Rear Band. Intermediate Band.

[mpasiuk]

Hello:

Upon re-assembly of my th400, I know that I have to soak the intermediate band and clutches for about 20- minutes in ATF. I'm almost sure (but checking do I have to soak the rear band also for the 20-minute time period?

Thx,...Mike

 

[crashbox455]

soak 'em all.

 

[Metalguy]

As long as you have the trans. out, you might want to take some measures against the dreaded pump "bushing walk". Most of these GM trans. have the same problem. The oil leakage between the converter snout and the front bushing flows thru a small hole, ~1/4" dia. That hole cannot flow enough oil to avoid pressurizing (and therefore large leakage) IF the bushing wears more than a few thousanths of an inch. Some of those holes were also drilled on the corner of the bore, instead of on the front face (vertical face) where it belongs. The problem is sneaky. IF the bushing "walks" a bit forward, like many of them do, it will partially block the hole--INSTANT large leak.

I always made sure to "port" such holes to make sure they could flow enough oil even if the bushing moves forward. I also drilled the holes a bit larger. Also use high-temp. Loctite bushing mount on the bushing OD.

 

[mpasiuk]

Thanks for the advice.. I'm already doing a bunch of mods to trans, but did not know of this front pump bushing problem. I did not install the bushings to any of the parts.. I had the local machine shop perform the work.. I wish I would of bought the tools and installed them myself.. hindsight

This is my first tranny rebuild... Are there any other bushings I should double check for similiar problems...

Thanks again

Mike

 

[Metalguy]

None that I'm aware of, but it's pretty easy to pull the pump and do the mod. *I* sure wouldn't install one w/o it--having had a vacation ruined when my switch-pitch T-400 I had in a '74 Camaro decided to walk the bushing as I went back to 1st gear to blast around some slows near the entrance to Bryce Canyon. Too a while to figure out why it was pouring trans. fluid from the front area. Found a very friendly garage that allowed me to remove and examine the damn trans. Worst part was that my WIFE noticed the different-color band that had been under the bushing and said "Why is that area a different color than the rest?", as I was closely examining the front lip seal and finding it perfect.

 

[enginesrus]

You can pour the fluid on the bands, just keep doing it till they are saturated.