Indy 1968, Rindt and Brabham

Jochen Rindt had signed for M.R.D. (Brabham) for the 1968 season. He and Jack Brabham drove the unreliable Brabham-Repco BT26's during the F. 1 season, Rindt obtaining no wins just two 3rd places.

M.R.D. entered also the Indy 500 in that year, and I seem to remember Brabham didn't want to race, so just one Brabham-Repco was in the starting grid, driven by Jochen Rindt, #35 - retired on lap 5 for a broken piston.
I've read Jack, after the 1964 accident that claimed the lives of Sachs and McDonald, had promised his wife he couldn't start again the brickyards, but this is not true, because he raced again in 1969 and 1970.
Why did team Brabham entered just Rindt and not Brabham at Indy 1968? Or was Brabham entered in the field? did he do some practice at Indy or even he was not at the circuit?

Who knows?

I'll venture an opinion here, and I stress it's without knowledge...

Jack was probably more interested in the World Championship... and Repco were up against it to some extent with the DFV now on the scene and repeated valvegear failures (in Europe only) in their 4-valve engines.

No doubt Monaco clashed with Indy that year in some way or other... as usual.

I'd guess that Repco's resources were sufficiently strained and that Rindt's appearance was all they could manage.

Brabham took a "refresher test" in Rindt's car, the #35 on May 5th. He denied that he was going attempt to qualify, but was out shaking down the car. The choice of primary driver may not have been Brabham/MRD's, Goodyear may have made the choice.

The second car, #95 was put up for sale as soon as the field was full (May 27th or so). The Fox history has (only) Masten Gregory testing the #95 and no qualifying attempt.

Ray, you may be right about Repco's problems. According to Autoweek they were trying to develop (a Goodyear commission) the Indy 4.2 litre engine AND an Indy 2.8 turbo at the same time. The turbo had serious FI problems that were never sorted.

One dilemna that Repco had that year was the valvegear failures...

Not the fact that the things were failing, but that they never failed in bench testing, only in Europe. Phil Irving came out of that exercise convinced that such engines could be better off with two different oiling systems... one for the top end, one for the bottom end, each using a different kind of oil.

Uh... yeah... the oil used in Australia and in Europe was different.