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1960s Armstrong dampers / shocks


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#1 giffo

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Posted 27 March 2010 - 12:06

Like alot of the old 60's formula cars they used the Armstong coil overs which had the adjustment knob on the side.

I know they are rebuildable and the set I have here are at about that stage of needing an overhaul. However before I head on into pulling them apart and causing myself too much grief I've been looking around for some re-build info on them. I have yet to find anything useful so I'm hoping some one here may be able to help.

Does anyone have an exploded view of one of these units that they may care to share?

Thanks in advance & Cheers

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#2 John Brundage

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Posted 27 March 2010 - 12:24

I've not had much luck getting these rebuilt from vendors. If I could find a source for the top seal, I would do it myself. There is also an o-ring that tends to leak at the adjustment screw. If you pull it apart, you will see that there are different size orrifices on the screw that vary the fluid flow.

#3 tedwentz

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Posted 27 March 2010 - 19:50

I've got a set of them for my vintage Brabham and would like to run them if I can get them rebuilt. I understand that the only chappie in the UK who could do so no longer rebuilds them. I tried to get them done here in the States, but that didn't go well. Please let me know if anything develops. It would also be nice if someone could unearth the technical specifications for the Armstrong part numbers. TW


#4 Dale Harvey

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Posted 27 March 2010 - 23:05

I have a set of those shocks and had them rebuilt by Bill Roberts at Grizzly Shocks in Seven Hills Sydney. There is also a firm in Victoria that do them. I think it is RG Leslie and Sons. I can dig up the exact contact details if anyone requires.
Dale.

Edited by Dale Harvey, 27 March 2010 - 23:06.


#5 giffo

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Posted 28 March 2010 - 00:31

I have a set of those shocks and had them rebuilt by Bill Roberts at Grizzly Shocks in Seven Hills Sydney. There is also a firm in Victoria that do them. I think it is RG Leslie and Sons. I can dig up the exact contact details if anyone requires.
Dale.


Hi
I'm not too concerned about finding a re-builder persay as my brother is a L.A.M.E (Licenced Aircraft Mainenance Engineer) and does many simiar rebuild jobs plus in a previous life I was a toolmaker/machinist. As for seals Transeals here in Perth they will/can make any seal you want if a standard one is unavailable. The trick is (I believe) will be to atleast see how they are assembled before dissassembly so as to try and find any issues before one could inavertanly break a critical part that may not be available. The other thing is my usual buget it so tight it doesn't extent to being able to pay for what is essentially a labour job when for me that is the part I can manage myself.

It sounds to me by a couple of the posts and what I have found to date elsewhere there are quite a few people around who would be interested in the same information.

Cheers.

Edited by giffo, 28 March 2010 - 00:32.


#6 Ray Bell

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Posted 28 March 2010 - 10:08

Repco's Super Seals division used to do the seals...

WW Shockabsorbers in Brisbane were a whiz on getting all of this stuff done. But they're only Armstrongs after all, are they worth the effort?

#7 giffo

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Posted 28 March 2010 - 10:35

But they're only Armstrongs after all, are they worth the effort?


Hi Ray
Are they worth the effort? YES.
You know how the movement is with originality. Since the car had them originally that is how it shall be now. Based on this principal that's how I'd like to keep it. Anyhow it's only a mechanical hydraulic item so they can't be too hard to rebuild. Can they?

Edited by giffo, 29 March 2010 - 09:46.


#8 horizon

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Posted 28 March 2010 - 16:08


Are they worth it ? In one simple word: YES !! I have them on My McLaren M4. They work really really well. I have pulled them apart and changed seals, main shaft and oil. I do have the Luxury of a shock dyno to test them though.






Hi Ray
Are they worth the effort? Unfortunatly YES.
You know how anal the movement is with originality. Since the car had them originally that is how it shall be now. Basid on this principal that's how I'd like to keep it. Anyhow it's only a mechanical hydraulic item so they can't be too hard to rebuild. Can they?



#9 Ray Bell

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Posted 28 March 2010 - 16:35

I thought M4s had Konis from new?

The Niel Allen M4a had them, anyway. I remember in 1970 they were sent back to Oud Beyerland for rebuilding.

#10 horizon

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Posted 28 March 2010 - 17:58

Ray,
The M4's used Armstrongs (according to the manual/parts list). All the Pics I have of M4's show Armstrongs. The M5A (F1) used Alloy Konis in 67, So it's likely that Neil Allan updated his car to the Konis.

Cheers

I thought M4s had Konis from new?

The Niel Allen M4a had them, anyway. I remember in 1970 they were sent back to Oud Beyerland for rebuilding.



#11 Ray Bell

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Posted 28 March 2010 - 22:42

Maybe not Niel...

Maybe it was Piers Courage who upgraded? 8212s, in those days the nectar of the gods.

Edited by Ray Bell, 28 March 2010 - 23:26.


#12 BT 35-8

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Posted 28 March 2010 - 23:18

I am in the midst of all this for my BT 35 and eligibility wise as well.

S.G. Leslie in Melbourne will do them , but they have advised they can only repair the
big external knob type , not unfortunately the screw driver slot type which is what I have on my car ,
due to the original manufacturing style on the later type.
That is their version anyway.

Bryan Miller.

#13 giffo

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Posted 29 March 2010 - 09:51

I have pulled them apart and changed seals, main shaft and oil. I do have the Luxury of a shock dyno to test them though.


So Horizon
From your post are you suggesting the refubishment is pretty straight forward for the knob style Armstrongs and to have them put on a shock dyno afterwards.
Whould that be correct?
Cheers


#14 horizon

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Posted 29 March 2010 - 16:59

giffo,
Yes ;) Even if you have to change the shaft (bent/rust) any machine shop can do the treads and hard chrome for you.

Good luck




So Horizon
From your post are you suggesting the refubishment is pretty straight forward for the knob style Armstrongs and to have them put on a shock dyno afterwards.
Whould that be correct?
Cheers



#15 giffo

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Posted 29 March 2010 - 22:28

Even if you have to change the shaft (bent/rust) any machine shop can do the treads and hard chrome for you.


Thanks Horizon
20 years ago when I used to build hydraulic & pneumatic actuators from scratch you could buy hard chromed stock bar in those small sizes. I should expect nothing has changed there. My ones will indeed need replacing.
Buy the sounds of it, it may pay to take some details and images when I get around to doing this to share here. It appears that there is a need for this info to be out there for eveyone.

#16 John Brundage

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Posted 30 March 2010 - 01:41

I have done the screwdriver slot type a number of years ago. If I recall correctly there is solder that needs to be removed and a thin lip to roll back before the screw is removed to replace the o-ring. A carefull touch is required when re-soldering so as to not damage the new o-ring etc.

#17 BT 35-8

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Posted 30 March 2010 - 03:10

Thanks John,

I knew that was the case , the people here don't appear willing to spend the time with them,
they would rather sell new AVO or Gaz or Koni.
I would happily send mine overseas as I have accumulated a few spares and also have them on my 74B March .

#18 M bennett

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Posted 31 March 2010 - 10:29

Thanks John,

I knew that was the case , the people here don't appear willing to spend the time with them,
they would rather sell new AVO or Gaz or Koni.
I would happily send mine overseas as I have accumulated a few spares and also have them on my 74B March .


I have some experience with Armstrong units. I used to be their Engineering Manager at their plant in Sunshine Victoria until they closed in 1984. I have a brochure and sectioned drawing of the screw adjustable units which I could scan and email. I also have many old parts lists and application listings.
Since then I had reason to rebuild the 1957 Armstrongs (non adjustable) on my Lotus in around 1994. This is the process I used.
Sent the units to S G Leslie who unrolled the closure and sent all the loose pieces back to me. I had the rods ground and rechromed to size (with mounting eye still attached) I found an NOK oil seal that would replace the old rubber bung style seal. Alternatively I believe a urethane seal could be machined to suit. Inspected and cleaned all the parts. There is seldom any broken/fatigued parts in racing shocks due to the low miles/hours of use. I then sent all the bits back to S G Leslie for re-assembly. Here a problem arose. They were roll closed but the oil used had a way too high viscosity. They came back almost rigid. I could not risk another round of unrolling and re-rolling so I had to resort to a drill/punch process through the base cap to drain the oil. I then obtained correct viscosity oil from Monroe and refilled the units using a syringe. The small hole was then plugged and cold soldered. The unit was then fine, so don't forget the importance of using/getting the correct viscosity oil which is specially formulated with anti-foaming properties etc. The net result is I still have the original 1957 shock absorbers on the 1957 car.
Looking at the drawing of the screw adjustable unit there are two issues to watch. Firstly on reassembly is how to locate the adjuster tube into the adjuster assembly? Could be done by a scribbing/alignment process. Secondly to replace the O ring in the adjuster unit does require the ability to undo a small roll over and then be able to reassemble/stake.
Trust this may help
Mike Bennett


#19 giffo

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Posted 03 May 2010 - 05:14

A bit of an update, I have now disassembled my 4 Armstrong’s for rebuilding. As suggested they look like a pretty straight forward job to refurbish and there is nothing inside that looks too difficult. There is a small difference between a 1960/61 model & 1966 model but nothing major. (I have the earlier ones on the front) Of the 5 seals needed it appears only the stem seal is not an off the shelf item and needs to be made, the rest are plain old O-ring’s. As for shock oil I have found AMSOIL do a couple of variants which is available locally (See link)
I suspect the major reason for these dampers to not operate correctly is due to oil level. I found 3 shocks with 100-120ml of oil & 1 with 200ml. I suspect the correct amount should be in the order of 250 to 300ml in each.
Next is stage two which is to have new shafts made rather than re-chrome the old ones (this turns out to be the cheaper and my preferred option) and then get the bodies re-cad plated.
If anyone is actually interested I can post a few images as I progress.


http://www.amsoil.co...efront/stm.aspx

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#20 Bowinracer

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Posted 03 May 2010 - 14:01

A bit of an update, I have now disassembled my 4 Armstrong’s for rebuilding. As suggested they look like a pretty straight forward job to refurbish and there is nothing inside that looks too difficult. There is a small difference between a 1960/61 model & 1966 model but nothing major. (I have the earlier ones on the front) Of the 5 seals needed it appears only the stem seal is not an off the shelf item and needs to be made, the rest are plain old O-ring’s. As for shock oil I have found AMSOIL do a couple of variants which is available locally (See link)
I suspect the major reason for these dampers to not operate correctly is due to oil level. I found 3 shocks with 100-120ml of oil & 1 with 200ml. I suspect the correct amount should be in the order of 250 to 300ml in each.
Next is stage two which is to have new shafts made rather than re-chrome the old ones (this turns out to be the cheaper and my preferred option) and then get the bodies re-cad plated.
If anyone is actually interested I can post a few images as I progress.


http://www.amsoil.co...efront/stm.aspx

I for one, am very interested. many thanks for this interesting topic. :up:

Edited by Bowinracer, 03 May 2010 - 14:01.


#21 bradbury west

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Posted 03 May 2010 - 15:56

It is always worthwhile having core info posted as it offers a formal record for the future. My Armstrongs, stamped 5/61, were rebuilt some years ago by Leda in the UK.
Your Amsoil link takes me back to the days when I was involved with them in 1981/2
Roger Lund

#22 hiteknz

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Posted 04 May 2010 - 08:31

It is always worthwhile having core info posted as it offers a formal record for the future. My Armstrongs, stamped 5/61, were rebuilt some years ago by Leda in the UK.
Your Amsoil link takes me back to the days when I was involved with them in 1981/2
Roger Lund

Yes very worthwhile information to have on record ,as time moves on a lot of the people who know or the information itself is lost,a couple of images sometimes answer a dozen questions

#23 John Ginger

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Posted 04 May 2010 - 09:08

I for one, am very interested. many thanks for this interesting topic. :up:



Me too, please post photo(s) as and when :up:

#24 Ray Bell

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Posted 04 May 2010 - 11:56

You will probably find, giffo, that the correct volume of fluid is, with the damper assembled and the shaft fully extended, enough to fill the working chamber (the inner cylinder) plus enough to half fill the outside chamber, the reservoir.

Castrol used to have a product called 'Shockol' (not sure of the spelling) that was good. I would caution you to not fall for the idea that heavier oil will help as it has two disadvantages. First it will endanger any parts that are fragile when its cold and thick, then it will lose viscosity as it warms and therefore damping efficiency.

#25 Lee Nicolle

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Posted 04 May 2010 - 15:03

I guess that most people who rebuild shocks could supply the correct oil. Ask the sprintcar guys who does their shocks as you are in Perth?
Otherwise Topperformance in Victoria [Koni] Grizzly shocks in Sydney or Wayne Randall, Shock Doctor in Qld should be able to supply. Dont put too much oil in them as they will not work properly.

#26 giffo

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Posted 05 May 2010 - 00:48

I'll get to some of the disassembly images soon but as for oil in the link earlier I should have posted the lighter of the two oils as what I have found out is the oil viscosity required is also relevant to the cars weight & what it's used for.
So I’d select the number 5 & not the number 10 as in the link.
As for the qty of oil so far I have based it a little on assumption as, as I said 3 of the 4 shocks had near 100ml & 1 had just over 200ml. While none leaked this is probably more due to the fact that they were near empty. The state of the seals & shafts suggests that they should leak if enough oil is present. If one was to just fill them up you would easily get more than a 2/3rds of a litre in them.
So Ray & Lee as I progress I'll check up on your suggestions but for now getting them ready for new shafts & having the bodies prepared and bead blasted for cad plating is my priority. Plus since I can only use the equipment I need on w/e's the going will be relatively slow.

Edited by giffo, 05 May 2010 - 00:49.


#27 Ray Bell

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Posted 05 May 2010 - 01:14

Originally posted by Lee Nicolle
I guess that most people who rebuild shocks could supply the correct oil. Ask the sprintcar guys who does their shocks as you are in Perth?
Otherwise Toperformance in Victoria [Koni] Grizzly shocks in Sydney or Wayne Randall, Shock Doctor in Qld should be able to supply. Dont put too much oil in them as they will not work properly.


It's actually Proven Products (now located at Albury) who Koni appointed as distributors for Australia...

They also make what was the Koni motorcycle range under licence, Koni having bowed out of the motorcycle field, so they export containerloads of these under their brand name of Ikon. They also sell them locally, of course. Proven Products have been the Koni distributors since the inception of the business under the name of Peter Antill Motors in 1959.

It's not by accident that I put forward that volume estimate by the way. That's how it's done. I can also provide a guide if there's a desire to uprate them, or to compensate for piston wear. Another good thing if you're working on these adjustable AT9s is to collect low mileage standard AT9s (they were used on a wide range of cars, there should be some sitting on shelves somewhere) and use these for components.

Many of the bits are just the same as the standard shocks. Pistons might be, shafts are and come in various lengths that can be cut to size, the working cylinders likewise to replace any that are scored internally etc.

Glad you're aware not to go too thick in the oil. There aren't many shock reconditioners today, but even so there are still some out there who rely on thicker oil to overcome damping efficiency lost to wear on components, all to the detriment of the user when the things heat up.

#28 giffo

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Posted 05 May 2010 - 03:20

It's not by accident that I put forward that volume estimate by the way. That's how it's done. I can also provide a guide if there's a desire to uprate them, or to compensate for piston wear. Another good thing if you're working on these adjustable AT9s is to collect low mileage standard AT9s (they were used on a wide range of cars, there should be some sitting on shelves somewhere) and use these for components.

Many of the bits are just the same as the standard shocks. Pistons might be, shafts are and come in various lengths that can be cut to size, the working cylinders likewise to replace any that are scored internally etc.

Glad you're aware not to go too thick in the oil. There aren't many shock reconditioners today, but even so there are still some out there who rely on thicker oil to overcome damping efficiency lost to wear on components, all to the detriment of the user when the things heat up.



Ray you make a good point and one I hadn't considered as yet. My brother regularly has shafts ground & re-hard chromed for aircraft applications & this is at quite a cost plus I have had an estimate on a new shaft to be around the $120 plus mark each. I have most of the tools to make these myself but cutting & scavaging bits from modern shocks is something I'll take a good look at.

Below the disassembly of the 1960/61 Armstrong Damper with 2 images at the end showing differences with the 1966 model

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prior to disassembly
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spanner for the top retainer
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exposing the top seals
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Showing the cap & shaft seals
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Lifting out the assembly
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Assembly removed
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Piston removed from shaft
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The inner workings of the piston (shown in assembly order)
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Main stem seals & washers (a wavey shaped washer was followed by 2 tapered ones & then the shaft seal)
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The parts & seals (in assembly order) of the adjuster
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This shot partially shows the difference with the 1966 shock to the 1960/61 shock above . The foot valve on the bottom of the tube seen here is the same for both
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The 1966 shock with the piston removed

This will be it for the time being & I'll post more as they are refurbished

Also I suggest not quoting this post so as not to duplicate the images more than needed

Edited by giffo, 05 May 2010 - 04:30.


#29 CharlieFarley

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Posted 14 May 2010 - 10:39

Hello All,

Would anyone know where i might be able to obtain these shock absorbers circa 1966 period ?
Many thanks for any help offered.

#30 giffo

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Posted 24 May 2010 - 00:10

Bit of an update as things are going quite nicely

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Parts ready to be sent for CAD Plating (gold colour)

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Parts that I made - new ends for all shocks

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More parts I made being the hard chrome shafts, The original pistons have been fitted and you can see some of the seals.
The 4 black ones are just O-rings & 1 Stainless steel split pin. Enough for one shock. The main shaft seal (blue) shows 2 seals. one each way for viewing. Missing still is the shaft wiper. After discussing this at the specialist centre (Transeals) it was determined that a modern approach would be better and use off the shelf seals than having something made. I haven't done a full assembly as yet but it appears and measures that the seals will stack over each other in the existing space. I did need to machine the retaining cap to take the minimum dia of the wiper seal. I'll post the part numbers once I confirm all is kosher.

Posted Image
Polyurethane Bump stops I made. I redesigned these from the originals as the poly is harder than the natural rubber. By tapering the bore as seen in the left stop allows for a softer stop that gets harder progressively

Point to note...
If you were to pay for this service and have some specialist rebuild your 1960 Armstrongs then I'd suggest you'd expect to pay around the same price as you can buy a new set of Spax or Avo shocks (about $1000 to $1250 Aust) or more?
I have managed to do most of this myself but some of the figures are Seals $65, Polyurethane $50, Cad Plating $150 approx, shafts I was quoted around $120 plus each and rechroming to be even more, Oil $50,
Time is the big one and I'd say I'll end up spending 6 or 7 hours on each shock, half the time if I was to do another set of shocks, now I know what I'm looking out for. This is still going to cost me around the $350 mark total by doing near all of it myself.

Lastly... the threads on the hard chrome shafts. They are 1/2" size on each end. The shock tops are UNF @ 20 TPI to take rod ends etc but the pistons are UNS @ 24 TPI which is both rare and came as a bit of a shock to find.

UNF = Unified Fine thread
UNS = Unified Special thread

Cheers & I hope this helps

Giffo

Edited by giffo, 25 May 2010 - 03:45.


#31 giffo

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Posted 28 May 2010 - 10:53

Seals
You can get more info and downloadable PDF docs of the Halite seals from the transeals website. Google - Transeals, Perth, Australia

Rod Wipers - Halite - Rod Wiper Type-831 Size RMW,14,20.6,3.8-831 (1 per shock)
Main Seals - Halite - U'Ring Hythane Type-601 - Size M24,14,8-601(1 per shock)
O-Ring - 5.0 x 1.0, NBR-70 , 5x1N7 (2 per shock)
O-Ring - 40.0 x 4.0 NBR-70 , 40x4N7 (1 per shock)
O-Ring - 0.239"x 0.070" NBR-70 , 010N7 (1 per shock)(edit 25-06-10 - this what was supplied but is wrong. I have used a smaller o-ring but do not have the part number)

Edited by giffo, 25 June 2010 - 11:48.


#32 giffo

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Posted 19 June 2010 - 14:20

I'm starting to get to the business end now

Posted Image
All the parts are back from being plated and the all the bearings have been fitted

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This image shows the tapered flat washer, main seal & wiper. You may note that in previous images there were more washers. Due to the different seal set up these were no longer needed.
The one taper washer is still required to protect the seal from the oil hitting/squirting onto the one spot. Again see earlier images to note the holes in the body which would be directly under the seal.

Posted Image
This image shows the wiper and some post plating machining. As the wipers arrived after the parts went to be plated I needed to machine some relief to allow 1. the seal to fit more correctly and 2. or the main reason is the retaining cap didn't fit up with the other parts correctly. This turned out to be better as now wiper is located more correctly and securely.

Posted Image
This image show one seal assembly

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This image shows the 4 shocks in preassembly. Next is to secure the tops to the shafts correctly.

I'll be picking up some oil next week for final assembly of this project next weekend.

#33 fredeuce

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Posted 19 June 2010 - 21:21

Whilst this thread has been devoted to the telescopic variety of Armstrong shock absorbers I would like to see a similar discussion and input on the overhaul of the lever action variety.

There doesn't appear to be much info around on these. Any manual you find simply doesn't deal with the issue. For example the factory manual I have for Austin Healey Sprites and MG Midgets has a meagre one page devoted to hydraulic dampers. Basically, what it says is that they must be returned to the maker for adjustment or repair. Not at all helpful. These are used a lot in older cars and various competition vehicles. It would be fitting to have something about them on here.

#34 Lee Nicolle

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Posted 20 June 2010 - 08:29

Whilst this thread has been devoted to the telescopic variety of Armstrong shock absorbers I would like to see a similar discussion and input on the overhaul of the lever action variety.

There doesn't appear to be much info around on these. Any manual you find simply doesn't deal with the issue. For example the factory manual I have for Austin Healey Sprites and MG Midgets has a meagre one page devoted to hydraulic dampers. Basically, what it says is that they must be returned to the maker for adjustment or repair. Not at all helpful. These are used a lot in older cars and various competition vehicles. It would be fitting to have something about them on here.

In my experience most cars with lever shocks have had them replaced with telescopic ones. At one time you could buy kits for early holdens and some small BMC products, eg Minors, Sprites, Lancers etc.
I think Giffos trials and tribulations with the Armstrongs would be easy compared with trying to repair lever shocks. In the old days the 'fix' was fill them with gearoil which did stiffen them but probably killed them. From memory Pedders were not interested in them when they first started with rebuilt tele shocks and that was 30 + years ago

#35 giffo

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Posted 20 June 2010 - 11:20

If you search MG, Austin Healey & Triumph forums I think you'll find answers for the lever shocks. Infact thats all I could find when I went looking.

Edited by giffo, 20 June 2010 - 23:49.


#36 Mistron

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Posted 20 June 2010 - 11:57

Point to note...
If you were to pay for this service and have some specialist rebuild your 1960 Armstrongs then I'd suggest you'd expect to pay around the same price as you can buy a new set of Spax or Avo shocks (about $1000 to $1250 Aust) or more?
I have managed to do most of this myself ......
Giffo


therein lies the key point of restoration surely?

Thank's for sharing, as I'm sure it will help others.

It does of course mean you'll now be rebuilding shocks for every old racer in the southern hemisphere!

top job, and well done.




#37 giffo

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Posted 21 June 2010 - 00:10

therein lies the key point of restoration surely?

Thank's for sharing, as I'm sure it will help others.

It does of course mean you'll now be rebuilding shocks for every old racer in the southern hemisphere!

top job, and well done.


Thanks for the kind words
Actually I wouldn't mind at all. (Doing other persons shocks) Send them on
I struggle to get the car on the track now. A bit of cash on the side would only help the cause.
I also think now my low estimate of 1k to do the rebuild is a bit low but each case would change depending on what was done or replaced.

Still I need to finish these four off and try them out first.

Edited by giffo, 21 June 2010 - 00:23.


#38 johnny yuma

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Posted 21 June 2010 - 05:39

The 1948-1952 Holdens had lever shocks,the Workshop Manual specifies NASCO shock absorber fluid (non-corrosive mineral oil based) for "only slight viscosity change over wide temperature range".The manual says only specialist firms should do up front shocks,but the rears can be done by a mechanic. Filling of the front shocks is easy by a filler plug,but the rears must be removed to fill as the end-threaded cylinders are horizontally mounted.They seem a very robust design,giving years of service on today's roads which are generally much smoother than the "good" old days ! Don't know if that NASCO fluid is still available though.

#39 Ray Bell

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Posted 21 June 2010 - 06:54

Seriously doubt it...

But it wouldn't be anything special. Castrol 'Shockol' was the go when we were rebuilding struts, it'd probably do the job fine.

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#40 ianselva

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Posted 21 June 2010 - 08:07

Front fork oil is available for bikes from most bike dealers , wouldn't that work as well ? It is also available in different viscosities.

#41 Lee Nicolle

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Posted 21 June 2010 - 10:41

The oil is not the problem, that is readily advailable. People who rebuild race shocks of any type can supply that. Or fork oil.
It is the parts to fix them that is the problem. We are doing with very old technology that is largely lost. A telescopic shock is easier to do than a lever action.
Which were never really much good anyway. That is why the telescopic shock replaced it and in its various form still around.

#42 Ray Bell

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Posted 21 June 2010 - 10:57

Obviously, with the amount of leverage on them, the transmission of the movement of the suspension to a shaft that in turn works pistons, there is a critical loss of motion and a reduction in travel generally... this means they have a lot of critical issues...

I was, coincidentally, talking to someone the other day who gets them rebuilt as a matter of course. $200 each, the things could never be worth that much!

Otherwise of interest, Peugeot dealers used to stock spare parts for rebuilding those heavy cast iron units used on 203s and 403s.

#43 johnny yuma

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Posted 23 June 2010 - 02:39

The oil is not the problem, that is readily advailable. People who rebuild race shocks of any type can supply that. Or fork oil.
It is the parts to fix them that is the problem. We are doing with very old technology that is largely lost. A telescopic shock is easier to do than a lever action.
Which were never really much good anyway. That is why the telescopic shock replaced it and in its various form still around.


Or are cost of production and ease of installation the main factors ? Struts and telescopic shocks rarely if ever receive a force parallel to the shaft at all times,this must wear out the seal,especially when a shaft on full droop plunges back into the damper body.A LEVER-ARM shock bolted to the body has an internal shaft supported at both ends and receives a rotating motion at a consistent right angle from a lever or levers.
Ultimately both shock absorber styles only contain internally fluid moving through an orifice or two so pushed by a piston or two,so can one necessarily be "better" than the other ?

Edited by johnny yuma, 23 June 2010 - 02:41.


#44 Ray Bell

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Posted 23 June 2010 - 03:04

There's a guide bearing below the seal that wears with uneven loading, not the seal...

The seal can be damaged by dirt or other contaminants or damage to the shaft.

Where the telescopic damper wins out in a big way is in the length of its stroke. This makes it possible to control the suspension much more easily than the lever damper with its tiny stroke and high leverage levels. Telescopic are definitely better, while at the same time probably cheaper and more readily fitted.

#45 Lee Nicolle

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Posted 23 June 2010 - 04:55

And a tele shock holds more oil and the shock is in the breeze normally so it can cool easily.
Heat kills shockers, that is one of the reasons most race shocks are alloy, they disapate heat quicker.
I think the poms invented lever shocks, they have a habit of making something simple very arkward, expensive and not very efficient.!!..Lots of Pommy cars had them.

#46 Ray Bell

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Posted 23 June 2010 - 08:05

Everything had some sort of lever damper before the telescopic was devised, which I think was in the thirties...

There were still American cars with levers into the war years, possibly coming out too. Holden, as previously noted, had them until late 1952, Peugeot had them up to the 403B on the front, the 403 all round (as the 403B shared rear axle with the 404, it went to telescopics at the rear when that model was imminent), and as you say the Poms had them by the bucketload.

Looking at BMC cars, there were a few standouts without them. The Isis, Oxford, Pathfinder and 6/90 of the mid-fifties had good old Girling telescopics with cooling fins around many of them, it was only when the Mini arrived that any other BMC car got them.

Don't neglect British Fords, though. Even Cortina station wagons, ISTR, had levers on the back.

#47 Lee Nicolle

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Posted 23 June 2010 - 12:30

Yes some American cars had them before and just after the war. The shock suppliers must have been doing good deals to sell them to the motor companys as they were out of date then.
That is I guess where Holdens inherited them from, and I think the shocks were Delco so it was probably a way to get rid of them.I may be mistaken but I think the narrow leaf springs ad something to do with the lever shocks.
The conversion kits to telescopic were advaiable in the 50s. I saw an add in a late 50s magazine I read recently.
I was a bit surprised that Pugs were using them so late as they were a innovative company of the day.
The Cortinas were what model? We didnt get them here until TC in wagons but I think the Poms had a few Mk1 wagons?

#48 maoricar

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Posted 23 June 2010 - 13:36

IST that level type dampers had, as part of their function, a role to play in suspension location.
Provided that they were properly maintained, they SEEMED to be quite adequate in most applications, including all but out and out competition use

I don't recall ever seeing them on Cortina wagon rears..but there's a heck of a lot that I've never seen !

#49 VAR1016

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Posted 23 June 2010 - 14:17

Lever arm dampers are horrible!

Over many years I was a victim of these mechanical abortions (Austin Healey 3000 notably)

I remember a section in the Race & Rally Car Source Book, that referred to a bloke called Forrest who in the 1950s/60s developed a radical racing Austin 7 saloon. Regarding the lever arm dampers he apparently experimented with various grades of oil to adjust the handling. He said "This method is cheap, effective and condemned by the makers."

I once had an Austin A60 van with the usual useless front dampers. I just used to fill them up every fortnight with old engine oil and enjoyed great handling for the first week or so.

Now here in France I have to work on some English cars. I bought a can of hydraulic oil for the front dampers on an MGB, one of which appeared to be completely empty! Much improved now, the car, though a bit oily in one place...

#50 David Birchall

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Posted 23 June 2010 - 17:30

I too spent my time with AH 3000s and their shocks...
It seems the answer, for me anyway, is to clean out the lever arm shocks fully and refill with 20w motorcycle fork oil-works very well on my DB2 but does not address the lack of a seal at the pivot point. There is also a spring loaded valve in the bottom of the shock which can be tightened up if req.

Edit: I would like to add how grateful I am for this thread-I have a pair of Armstrong adjustables for the front of my racing Elan and at some point I am going to have to restore them-now I have the info-many thanks.

Edited by David Birchall, 23 June 2010 - 17:33.