Some of you may remember a while back I had an 80E that would not shift into 2nd under hard acceleration after a trip to the track. This was after a few months of trouble free street driving. I almost sent it to FLT but the local guy that built it the first time offered to fix it for the price or parts only.
Well, long story short I've got the trans back in the car, and it has same problem.
The builder said the sprag was broken (turned both ways) and this caused the intermediate clutches to burn up.
I've double checked that the fluid level is correct, the converter was sent back to PI to be freshened up, and I've got a pressure gauge temporarily hooked up.
I went WOT one time, banged the rev limiter, never saw the pressure gauge budge. Tried it one more time, but let out to about 2/3 throttle and saw 75 psi on the gauge. The car was in boost at this point so apparently that is max line pressure.
This is a pretty basic build; alto red clutches, upgraded steels & vac modulator. This time I added a transgo HD-2 shift kit while it was apart.
I'm running the trans go blow off valve on the vac line running to the modulator.
The only other thing I can think of is to hook my vac/boost guage on trans side of the blow off valve to make sure the trans isn't getting boosted and that it is seeing the vacuum the engine is pulling.

Any other ideas what I can check? I've never checked line pressure before but I was thinking I'd be seeing somewhere in the neighborhood of 175 psi in boost. Is my line pressure way too low?
I hope I can figure this out without spending a shitload of money on this pile; but I'm not optimistic.
Any ideas of things to check before pulling it again are very welcome.

 

Unhook the vacume line from the modulator and start car you should see around 200-240 psi this way depending on the boost valve . 75 PSI would be approx correct for pressure at idle with vacume line hooked up. Both measurement are made in OD position idling

 

I'll be sure to try that, but I'm only seeing 25-35 psi @ idle with the car in OD. The 75 PSI was during a 2/3 throttle shift while in boost. That was the highest I ever saw the pressure go.

 

If thats true you have a pressure issue and will burn it up again

 

That's what I figured and that's why I parked it.
Is something in the valve body likely the culprit? I'm really hoping it is so that I can possibly get this fixed without pulling the trans again.
I'll see what it does tomorrow with the vac. line unhooked.

 

I would look at the assembly for the Modulate valve behind it then the PR valve

 

Well, I tried what you suggested & the results are not good.
I'm seeing no noticeable change in pressure from P to any other position on the shifter. They're all showing 35 - 40 psi.
Can you point me to my next step? I'm pretty ignorant when it comes to working on a trans, all I've ever done is R&R and filter changes so as detailed as possible would be good!
TIA

Craig

 

Thanks for the help perfomabuilt, he's willing to chat with me and help me figure out the problem and I didn't buy a thing from him. That's customer service!!!

 

Could the push pin be too long/short for the modulator valve? I know with the stage 3 kit you can cut it down for less pressure. Maybe too short? I'm no builder, just throwing it out there.

 

That's a good question. Is there an adjustment screw or something on the modulator? I talked to my builder, the PR valve is new; it came with the trans go HD-2 kit. He suggested before I do anything else I look into adjusting the modulator, but we didn't have time to talk specifics.

Can the modulator be adjusted??

 

Anybody?? Is it possible the modulator is way out of adjustment?