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Discussion Starter · #1 ·
Good Morning all,

It's been a while since I've posted here, but this issue is throwing me a curve ball.

I rebuilt my TH400 a little over a year ago with the upgraded clutches and steels. I also dual-fed the direct drum by removing the second teflon seal and plugging the main feed hole right of the center support bolt with a 3/8" cup plug in the transmission case.

Recently the transmission started acting goofy. When cold, the transmission refuses to go into reverse, when warm I have to rev the engine up to around 2,000 rpm to get it to pop into reverse.

Third gear wont shift out of second until a very high rpm when it's cold, somewhere close to 5,000 rpm. When hot it's a little better. The transmission also likes to slip out of 3rd if i drop RPM below 3,000.

The good news is the shift points are consistent, so I'm leaning towards a governor issue. Upshifts happen at 4,200 rpm for 1-2 and about 5000 rpm for 2-3. I have the B&M Governor recalibration kit installed with light springs and weights, I'm not sure what numbers, I'll have to check that later.

I have checked and verified the following:
-Fluid level, at cross hatch when hot, no bubbles, fluid clean.
-Replaced filter, there was a decent amount of clutch material in the pan (non-ferrous), I'm assuming from the clutches wearing in.
-Check ball locations verified, VB torqued to spec in an inner-to-outer sequence.

I have read a few threads on similar issues, most of which seem to point towards either the governor, modulator, or a direct drum issue possibly involving lip seals or teflon seals.

My first plan of action is to recalibrate the governor with heavy springs and weights, although, this doesn't explain the issue with reverse slipping or the transmission popping out of 3rd under light load/lower rpm.

Any help, advice, or reading materials would be very helpful and greatly appreciated.

Thanks.
 

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Discussion Starter · #3 ·
Another thing, when removing the valve-body to check the check balls my square-can detent solenoid fell apart. I didn't think anything of it since the detent solenoid isn't connected to anything. I read through the trouble-shooting section of the B&M Transpak instructions and noticed that it stated that a "loose or damaged kickdown solenoid" will cause late/no shifts. When I re-installed the valve-body I only installed the lower section of the broken detent solenoid. I'm thinking of replacing this since they're cheap and easy. I hope that's the issue.
 
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