TH 350 Prep for reinstall after engine rebuild

So while I have my 72 TH350 out the car for engine rebuild I will want to cleanup, change filter and fluid before reinstalling it and the motor. Any suggestions to or needed repairs while its out and accessible? What kind of fluid? Can fluid in converter be changed(haven't looked to see if there was a drain plug)? Are there orings on the trans dipstick tube? Kickdown cable tube? Looks like fluid leaked there before. I know I'd like to replace the rear seal. Is there a front one as well behind the converter? What would be recommended way to remove built up oil on outside case? Thanks and sorry for all the questions

Todd

 

Good luck with everything Todd. For the out side of your dirty pan i would use dawn dish soap and a wire brush. Dawn cuts grease and oil real good. Mix it with hot water.

 

Anyway to keep water out of the trans when and if washed with water?

 

To keep water out.. install the torque converter, dipstick and whatever else you can attach on the transmission while pressure washing. Take advantage of those seals! Plastic bags secured with zip ties on the coolant fittings are a pretty cheap alternative. They make a plastic plug for the tailshaft if you feel like spending a few bucks. The kick down can be plugged with whatever your imagination comes up with.

Besides the front, rear, and pan seals.. The servo and piston 0-rings, 2 speedometer o-rings, selector shaft seal, vacuum modulator o-ring, dipstick, kick down o ring, and I'm running out of ideas off the top of my head.. A kit from Summit covered a few different years and variations to give every seal needed. A search on youtube is instrumental in tips on the teardown.

 

Thanks for the information. But I definitely DO NOT want to tear into this transmission.. I'd like to replace the seals and orings I can do without tearing into it. Cleanup the outside of the trans and get it ready for reinstallation.

Todd

 

No prob, and all the things I listed are external seals. No need to dig into the guts. Easy stuff.

 

i'll just have to figure out where to get them all from

 

Had already purchased filter and gasket from rockauto. But prefer that one you posted with all the orings, seals and gaskets. So I’ll order that. Never though to look at Chevy TH350 ones

 

If you pressure wash it, do not point it directly at an sealed areas, like the front pump, shifter shaft or tail shaft. They are to keep fluid in at lower pressure and not high pressure water out.

One seal that is often overlooked is the speedometer housing. There are two seals, an o-ring on the outside and a very small lip seal on the inside. Inspect your speedometer driven gear to see if it has a groove worn in it. Mine leaked badly around one of my cars. Also, if you speedo is not correct, this a good time to change that gear when you reseal it. That ebay link should have all that you need. Front seal is most critical since it is impossible to replace without splitting the motor and trans.