1-2 shifts early

[HOTTOGO]

According to what you have listed in your previous post in your PR system and your last press. test, I'd say you definately need the the PTS pr system. I know it's throwing more $ at the trans but it is not just a performance mod, it is also for longevity. I wouldn't worry about the "buzz" or fluctuating needle, but the pressure drop is of concern. I think you'll be well pleased with the PR system. Try that and see what you have before going any further.

 

[Russ Merritt]

My early 1-2 is gone with the new parts, loaded direct drum, band, servo, gov, PR system, PTS shift kit, not terrible but softer than I would like 1-2 shift. 260 psi WOT, 225 at the shift 1-2. This tranny has done this forever and we can't seem to fix it.

 

[68Camaro]

I had sometime to drop the VB and check the Upshift Mod Valve, it was not sticking, but did not move freely either. Cleaned it up and made sure it would slide side to side under it's own weight. I also put the stock valve body plate back in and installed all the check balls attempting to get closer to stock. With this, I was able to increase the TV setting alittle and still maintain good 2-3 and 3-4 shift points. This did help, but did not completely solve the problem. About 50% of the time it makes the 1-2 shift correctly at 5000rpms.

The boost feed tube seems fine, l did locktite it in to be sure. The next item per Mark's suggestion will be the PR system.

With a .471 boost valve and a stock CZF Rev boost valve, what should my preassures be? Is my stock pump (added hardened rings) the root of the problem? The reason I ask is that a stock trans with a smaller boost valve doesn't have this problem.

Thanks,
Greg

 

[68Camaro]

1-2 Shifts early - Revisited

I was unable to solve this problem last fall, then snow came and I just put a cover on the car left it alone for a while. Some warmer days are starting to show up and I would like to get this figured out before spring.

Anyone have any new thoughts on why my 200R4 would make the 1-2 shift at 3500rpms at full throttle but all other shifts at 5000rpms. When it down shifts from 2 to 1, it will run up to 5000rpms for the shift. Also there is no boost in line pressure in R or Low. I have relpied to my last thread so all the details are attached.

Thank in advance for your thoughts.

Greg