I have a continuous leak where the driveshaft enters the transmission. Is this simply a seal that needs to be replaced? Scott
That's part of it...if the bushing that the yoke rides on is worn out, even a new seal will be leaking in short order. To find out, inspect it after you'd removed the old seal. The bushings are available for replacement if necessary. Devon
http://www.tciauto.com/Products/TC-'GMTH350'-0.aspx Here's one place, I'm sure there are plenty others. Or call a local tranny repair shop they might tell you some or sell to you indirect.
On a trans with a removable tail housing (TH350/400), I would remove the tail & rear seal, and check it for a snug fit over the yoke. No, replace probably the tail bushing and the seal, reassemble. Bruce Roe
How do i remove the tail housing on my TH350? Any tricks/tips, or do I just unbolt the driveshaft then unbolt the tail housing?
Unbolt the u joint u bolts securing the rear of the driveshaft to the yoke. Push the driveshaft forward, then down, and pull it out of the transmission. Unbolt the extension housing and, bring it to a transmission shop. Ask them to replace the bushing and seal. Be advised that you will lose transmission fluid when you pull the driveshaft.
Should I expect to lose all the trans fluid, or just a dribble? Is it possible that the yolk could also be worn/suspect? Thanks
I replaced my bushing this summer. It was fairly easy, but my car was on a lift. I drained my trans before replacing both the tail shaft seal and bushing. If the convertor drains down, I imagine you would lose a bunch of fluid. I think a trans shop familiar with older cars could knock this out in an hour or so.
You'll lose a quart or so. Depends on the angle. I would lift the car as high as possible in the rear, that will minimize the fluid loss. BTW, factory service manual and Chassis Manual are the same thing here.
