1971 Jeepster Tranny Question

[Steve]

Hello fellow Jeepsters,

My 71 appears to be having a tranny issue, but maybe it's normal since I am new to the vehicles. It is the original turbo 400 tranny behind a 1977 Buick 231 odd fire. The problem is that at idle, when I change from park to drive, the tranny pushes so hard that I have to really stand on the brakes and the engine almost dies. It even barks the tires on cement. The engine is rebuilt (tons of power!) and the idle is set at 600 rpm. It also shifts really harsh from first to second and from second to third. It's very drivable the way it is but it doesn't seem right. I just had the tranny R&R and I hoped they would fix the issue but they did not. They said the 3/4 ton tranny was too big for the vehicle and that's why it shifts harsh. I don't buy it though.

Any thoughts?

Thanks!
Steve

[justjeepsters]

I have had that problem and had to sell the jeepster. How much do you want for it...

Just kidding - it looks really nice. Most likely, you have a torque converter problem. The V6 had a higher stall than what normally came with a V8 - which most turbo 400 transmissions were bolted to. Most likely when you had it rebuilt they also replaced the converter with the wrong one with a lower stall. This will make them act as you have described.

The gear ratio can also affect this - but highly unlikely. You most likely have 373's and that should work fine.

Larger cam shafts can also affect the amount of torque sent to the rear wheels, but once again this is mostly on V8 motors - I vote for the converter

[RRich]

Try lowering the idle more. You'll probably need to adjust the idle mixture again.

[Steve]

If the idle speed is set correctly at 600rpm, does it matter what the mixture is?

Thanks,
Steve