72 Auto transmission adjust shift

[Jim T.]

Re: 72 Auto transmission adjust shift

Your description of upshifts under light accelleration are the same on my '72's THM400. Also, I don't have downshifts as Ted describes, I have to push way down to make it downshift. However, the upshifts under heavy accelleration are significantly higher. I havn't mapped them out, too busy smiling. While reading this thread I was wondering what the up-shifts should be for a THM400 under heavy accelleration and would the engine option matter. Mine is an LS-5.

My original owner 70 turbo 400 with 350/300 would shift out 1st about 60 and from second to third about 90. This was done many years ago. With the current engine, ZZ1 crate engine 350/340 I have not tried what speed it would shift from second to third at WOT. Speeding tickets cost to much money. Rear end is 3:08

[Edward J.]

Re: 72 Auto transmission adjust shift

Jim, the more RPMS your engine turns the higher the shift points can be. 70 LT1, LS5, LS6 had higher red lines, hench shift points may show a few more MPH between shifts. don't forget the axle ratios to also change things.

[Terry M.]

Re: 72 Auto transmission adjust shift

I have been under a lot of them (not recently though. My days of judging chassis are done, but we do get them on the lift sometimes at the Advanced Judging Seminars. ) but I haven't had too many on the bench -- not more than half-dozen anyway. I was under the impression that there is no adjustment on the original vacuum canister, but I will admit I have never looked. And of course in judging that is not one of the features, just like the date code on the canister, we don't look for.

If you tell me my impression is wrong, I'll believe it. It would be best for Ted to check -- he might have an easy way out of his problem.