I believe some of the bolts used to fasten certain suspension components in todays cars are self tapping. As such, the threads are easy to strip if a mechanic over-indulges his right arm. I thought about a helicoil but this is a major suspension component fastened with three bolts per side - the torque spec is 74 ft lbs. A few of the bolts that did not strip the unibody threads are torqued beyond 125ft lbs...this begs a question not fit to print...09!#$%!#^@&@$& Now there, I feel a little better.

Cheapracer, I sent you a PM about this but I feared you may not recieve it for a while...do the guns still work on that Mig? I know a place you can take a few shots at...

They are indeed self tapping. So the first thing we do is helicoil them and fit proper bolts. The reason they are self tapping is because over the life of a production vehicle they'll probably never be undone deliberately, and the consequences of them undoing accidently are at best annoying.

If you aren't using a torque wrench these days then you can't afford to just reef on every bolt.

Just got back home after a few days of isolation. I suggest you get to a bodyshop, they do this type of repair everyday of the week - obviously cars crash and tear out suspension mountings.

This is also a problem in life, you have engineers thinking up ways to cheapen production, which is great, thats their job but not looking forward to Apes working on the cars in the outside world later on.

Using a torque wrench backwards will not get you a reading of what they were done up to especially if some form of lock or spring washers are used that work against you.

I have found that in many cases the larger problem is the thread locking compound used on these fasteners. Methacrylate, balls up in the thread spaces as the fastener rotates, binds and tears the threads. If you can get to the nut plate with a torch you can cook the thread compound out of there, then carefully back out the fastener with an impact wrench. If you don't have a torch and an impact handy, then lots of penetrating oil and patience -- one turn out, one turn in, etc, until the fastener clears up.

...these are the same folks who dialed in 30 deg toe out front and rear...

I was quite pissy with the tech, I asked..."do you own a torque wrench?"

These 6 bolts are used to adjust toe so I am surprised that they are self tapping bolts - given that they need to be loosened every time an alignment is performed. but I understand the rationale for a quick assembly line.

So, a helicoil will work in this application? The bolt threads are fine - and I know I could have removed all the other bolts - I have lots of tools. But, I didn't want to risk a total failure while driving carefully to the shop...I figured if I remove the others they too may not thread to torque spec...I wanted to avoid a tow truck ride.

I've been around cars for many years, but for some reason I've managed to never experience these kinds of problems...I guess real car guys have been thru the lot.

Thanks for your help!

McGurie - I am still hunting down those codes for the CAN bus thingy.

Which "suspension fasteners" are you talking about? Your posts are like two-minute mysteries.

Rear suspension, trailing arm bushing...2005 mini cooper.

Each bushing carrier fatsens to the unibody with three bolts. This bushing carrier mates to the under side of the uni-body and it slides left or right which determines toe angle. The trialing arm fastens to the center of this bushing carrier and the other end the trailing arm has pick up points for the two equal length lateral links - upper and lower control arms.


"...two minute mysteries" ...what would you suggest?

With one bound he was by her side. Nora felt his hot breath as he ripped the thin silk...

...continue, please!



I wrote my openning thread with a little embarassment...so I walked around the problem with a shy question. I have idiots working on my car!

I feel myself starting to side with your mechanics. If you need a mechanic, that generally means you are probably not a mechanic yourself. In that case, maybe you should STFU and listen to the guy you hired to be the mechanic. If you can't do that in confidence you need to get a different mechanic and stop driving that one crazy. My buddy Dave has a sign in his shop posting his labor rate: $100 per hour, $200 if you watch, $300 if you offer advice.

EDIT: Sorry, don't mean to be rude. Just saying. Having idiots work on your car, I mean. Doesn't seem like that could turn out well.

I didn't take your note as rude. I know when to follow and when to lead.

However, my humble automotive experience has taught me that a torque wrench is a vital tool. In addition, after dialing in 30 degrees toe out front and rear on a production based car and stating "these are normal alignment for most cars" potentially highlights an individual who has probably not been behind the wheel long enough...or is carless...a follow up test drive should have in the least sent some tactile messages to the mechanics backside confirming a very unstable ride - lots of rear steer/bump steer...shockingly unstable McGurie! My background doesn't offer me the ability to define the physics, but the outcome is no different.

Bold statements perhaps coming from someone not formally trained as a suspension engineer. And although I have much to learn about cars, I would like to think that I have been fairly awake at the wheel while driving nearly 3 million miles thus far. I do understand your comments Mcgurie and referring to these guys as idiots is a sign of incredible frustration...on several levels. I was unkind.

I've seen that sign before and repsect it...the above is after several attemps sans my input...I have a sign in my car: I'll leave you alone if you get it right the first time, I'll pay 2/3rds your price if I have to bring it back once, 1/2 price if I have to bring it back twice and I expect the service to be free after I return the car three times...Okay, now I'm being a smart ass.

And at worst... deadly?

I think you mean 30 minutes.

Maybe 125ft*lb was in fact 125 N*m too?

0.30 degrees neg, yes - minutes.degrees seconds...infinitesmals

...just got the car back...the tech used silver anti-sieze on the bolts and this apparently allowed him to over torque the bolt. Re-tapped one size larger and all felt fine duinrg my 7 miles trip to the office.

Oh gawd. I hate those scenarios! I'm starting to remember why I chose working on computers instead of cars...but then there's the "make one small change, reboot (waiting five minutes) see what's different, make another small change, reboot" dance. But at least I'm not under a car skinning my knuckles....actually now I've talked myself into thinking working on cars is fun.

Who's McGurie? McGuire's evil twin/alter ego? (I know it's niggling, but I like the sound of it. Maybe McGurie is the one ripping the silk fabric.)

With one bound McGurie was by her side. Gruntguru felt his hot breath as he ripped the thin silk...

The reverse I might believe.

Nice!

The tapped threads did not hold...time to pull the whole lot apart and weld in studs.

Oh I meant to answer this before but I forgot the name of the darn things...

Ok todays tech Forum quiz, they (a round nut thingy) go into thin steel hole and with a special tool you expand them into the hole leaving a dodgy but actually very sound thread -

they are.......

RIV nuts!
http://www.aimfasteners.com/rivnut.html

and you can fit them yourself....
http://www.fjr1300.info/howto/rivnut-tool.html

I win a night of sultry sex with me! WOW! Oh and your invited Tony to narrate that story......

With one bound he was by his side. Meb felt his hot breath as he ripped the thin cellophane from the tub of round nutty things and opened his story book...

...the nutserts instantly satiated his desire and the warm deep sigh of relief hit him as he grabbed his...



Cheapracer - do you mean nutserts? I should have thought of that...not sure they'll hold the trailing arm bushing...but I've used these in other less important application with great success...easier than welding in studs for sure but the threaded shaft is pretty deep or long...this sounds really bad...

I probably wouldn't use nutserts or similar on a suspension application. What size and thread are the fasteners? What kind of access do you have to the original nut plates? How about posting a digital photo so we can see what you have?

I'll get a photo posted by Monday...unless I have time to get under the car before then.

M12 x 1.5 x 61.7 - three of these per side. Imagine a donut standing upright with a square plate sitting level on top. The donut is the bushing and the plate - with three holes in it - mounts the bushing to the uni-body. The holes in the plate are elongated to allow for toe adjustment. The trailing arm bolts to the center of the donut.

Access horribly tight...if studs are welded in cleaning any excess material can be accomplished with a toothpick; when reinstalling the bushing I have enough room for my hands and the bushing...that's about it.

In addition, the bolts are threaded into a hollow cavity - box frame? - as part of the uni-body. I would prefer not to open this structure from the top...I fear this might ruin the integrity of the uni-body. but, if I did have access from the top I could reverse thread bolts down thru this area and weld the head of each bolt. The excess weld material becomes a problem because the flange sitting on top of the donut must mate flush with the uni-body...I could add a thin spacer plate...I will get pictures