Vibration thats felt in the seat? Rear end...

[Cobra1894]

I have a vibration in my seat in the mornings and after work when the car is cold... What are the possible causes. I just replaced the trans mount, u-joints, tailshaft bushing and yoke. The rear end is a used replacement peice that has been in the car for a few months. The driveshaft has about 3/4 in play when I turn it by hand. Is my rear end shot? I need to upgrade my gears anyway, but is there anything else I should replace at the same time I do the gears? Thanks!

 

[ss93cobra]

One could imply from your post that the vibration goes away or isn't there when warm. Is that the case? Plus, get new bearings, races, seals, and clutches when you change the gears. Yeah, more time and $, but you won't have to mess with it again for years....

 

[blkstangman88]

If it was ur rear end u would feel it at any speed and no matter how warm or cold ur ca is, trust me, i bent my pinion at 70 on the freeway from the bearings exploding, and it felt like my car was going to fall apart. got it to the shop and it was bent 3/4in, looked like a bent d$#%.
id start looking other places first.

 

[Cobra1894]

What would explain the play in the driveshaft. I can rotate it 3/4in, and since it is a used rear end I thouhg that would most likely the cause. What are the other possibilities? I can feel the rear end screw up at slower speeds but it seems to get really bad the faster I go. As it warms up it seems to calm down but is still there. What would happen if all my oil leaked out from the rear? I have a small leak.

 

[srothfuss]

if you are sure it's in the rear end you could start by changing the diff fluid to see if that helps.

 

[Cobra1894]

Any other ideas...

 

[ss93cobra]

If all the fluid leaked out of the rear end, you'd be hearing all kinds of grinding and growling. It's not uncommon to be able to move the driveshaft slightly when the car is in gear and the engine is off. When you say you can feel the rear end screw up at slower speeds, can you explain that more specifically?

 

[tylerrocks]

If all the fluid leaked out of the rear end, you'd be hearing all kinds of grinding and growling. It's not uncommon to be able to move the driveshaft slightly when the car is in gear and the engine is off. When you say you can feel the rear end screw up at slower speeds, can you explain that more specifically?

Ditto

Tyler