i have a turbo II tranny on my first gen, i know i know im a first gen guy but nobody can aswer me this question on the first gen section. anyway back to the question, i put a custom driveshaft on my car and i had a vibration on it so i took it back and the driveshaft people told me that i have to replace my tailshaft bushing because the shaft on the yoke show a littel mark on it. and onther thing he told me that could it cause the vibration. i ask him anyways to rebalance the Dshaft and found i out that the driveshaft was out of balance, well instead of taking the tranny out i put the driveshaft in and drove it and didnt vibrate at all, now my question is do i still need to replace the tail shaft bushing? and how hard is it to replace? i know it cost 50 bucks i dont wanna spend 50 bucks if i dont need to. thanks

 

Reach under & shake the drive shaft near the front end.

If the tranny tail bearing is bad, you will feel the play.
If you can't feel lateral of vertical play, then no harm was done.

 

BTW if you park on an uphill grade, check that the rear seal is not leaking.

 

its not hard at all if you want to change the u joint it would take you about an hour for remove replace and reinstall . on the 1st gen they have a clip on the inside just remove the clips (4 total) and remove them reinstall the new u joint put grease into the new ends so the bearings dont come out install the clips one at a time then lube thru the grease fitting and wipe off the excess. i brought my u joint from mazdatrix. but it does not sound like you need to do that since it was rebalanced.