This is a followup to this thread: Good Vibrations!

I've checked the U-joints and they look and feel like they were changed shortly before I bought the truck so that isnt the problem. I've noticed that it only vibrates in 4th at about 1000-1200RPMs coasting....it's also started to make a constant noise in that gear like the clutch is rattling, but I just replaced the clutch and haven't noticed the noise any other time. Also, the "seal" (?) on the back of the transmission, where the driveshaft exits the transmission assembly, is leaking a little bit of fluid. It almost act's like a bearing is going bad...I don't know much about how these trannys are put together so any help with this would be appreciated!! thanks!!

 

May be low on fluid from the leak - also check the yoke for radial play in the tailshaft housing bushing - also check the center carrier bearing

 

ive checked the fluid recently and it is normal. its not leaking a whole lot, just enough to splatter some on the underside of the truck...there is a bit of play in the prop shaft...what do I need to do?

 

so you got your clutch installed? hope it went alright for you.

That vibration sounds alot like one I had. Mine turned out to be a u-joint. Couldnt tell it was bad until I actually disconnected the driveshaft from the axle.

 

Yeah, I just ended up having a friend with a shop do it for me. It was too stinkin hot around here to lay under my pickup for a few hours and he offered! The new clutch seems to be working a lot better! He said the old one was pretty much used up, so im glad I got that done. I will take the driveshaft off and look at it closer this week and see if the u-joints are bad...Do i need to do anything with the seal around the propellor shaft while im at it?