can anyone advise about how long it will take to replace the output seal (I have slow but steady drip)? and while I am in there should I replace the bushing as well? any special tools required? I have never attempted this before and would appreciate any advise.

1st project/daily driver
91 RS w/ 350 swap

 

A simple seal replacement is under an hour, if you've done it before. What bushing? You mean the u-joints?
Tail Seal Replacement
Driveshaft & u-joint r&r

 

I thought that I read that there was a bushing inside the output shaft. and that people say that you should replace it while you are in there, and that it actually is the likely cause for the leak. i know to check the u-joint while I am under there just by seeing if there is any play in the drive shaft. Have I read the somthing wrong? I know you have posted to some of my previous questions and I appreciate it...this is all new territory for me as I have only worked on cars years ago with my brother and have just recently decided to take a chance on a car that I have always wanted...just trying to get her up to snuff and I am sure I will post many more novice questions.

 

The tail shaft is suspended out from the rear of the trans case. The tail shaft housing (cone) bolts onto the case and it covers most of the shaft. There is no bushing inside the tail housing. The tail shaft rides on a bearing, but you would need to completely dismantle the trans to get to it. Tail shaft is the first part in, and the last part out. Your tail shaft could have more than normal slop in it, but it would require a rebuild to address it.

 

The outside surface of the yoke (attached to the drive shaft via a u-joint), slides onto the output shaft of the trans. The way the seal works is it seals around the drive shaft yoke. So the other thing you will want to check is the yoke itself where the seal rides on it.

The yoke over time get worn down in that one spot where the seal rides, creating a slight depression around the diameter of the yoke. It would be small, and not often does it happen but it can.

If you can mark with a sharpie on the yoke right up against the seal that will give you an indication of where the yoke, if there is a grove, is worn.

There is a radial spring that is part of the seal, which is what helps it to hold to the surface it is sealing to. You could slip the new seal over the yoke before you install it to see how it fits the yoke. Make sure the yoke is clean.