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I pulled a th400 out of a 1971 350. How do I know if it is any good? The car wasn't running when I got it, so I don't know if it still works. what are some things I should be looking for on it?
Short of pulling the pan and checking what’s floating in there, you can’t tell much by looking. You’d need to pull the valve body and do some air checking. Not really a DIY project. Messy and possibly unforgiving. Buy an ATSG and/ or Ron Sessions repair manual before you”dig in” so you can see what you’ll get into. Procedures and cleanliness are key.
Or you could take it to a transmission guy. But I’m sure they’ll tell you it needs rebuilt…..
Good advice above...You need to remove the pan anyway to change the fliud and filter. Catch all sluged and metal particles in a large clear plastic container so members can identify what clutche/seals/gears might need replacing.
My TH400 had a slight buildup of black sludge in the bottom of the pan, BUT the fluid did not smell burned or look discolored. After servicing the trans, it worked perfectly. The shiftdown solenoid did fail later but that was only a $35 repair.
Even if it does meed rebuilding, a basic $250 kit will normally do the job. After diriving the car a few thousnad miles, remove the pan and check fo large metal particles to see if gears need replacing.
Look for water or rust in the pan from sitting a long time, maybe outside. Any corrosion or rust in the trans or valve body is not good.
Not all Th400 were built the same. The late 60's had better 2nd gear and sprags then the later ones.
When I rebuilt my original 72's Th400 I used an early drum and sprag, along with the hot rod tricks to the pump and valve body. I made an adapter from black pipe and angle iron to mount the trans in my eng stand.
Th 400
