This maybe a gears and axle question (I am posting it in there also), But i figured that I would ask it here also.

Here's the scoop, I am getting a terrible vibration coming out of the drive train. I figured it was out of the drive train since I feel it mostly in the seat. It gets REALLY bad at around 90MPH, but you can feel it around 15-20MPH also.

I replaced the U-joints last summer and they only have 2500 miles on them, the rear end was completely rebuilt this winter (due to pinion bearing failure), I put in a new Poly trans mount since the stock one was shot, and I 180 the drive shaft thinking that it was put in different then before the rear end rebuild. I had this vibration last summer, but i thought that maybe it was because of the bad pinion bearings.

I was wondering if maybe the drive shaft is out of balance? I have also heard that the 4L60E trans. had a problem with the output shaft bushing/bearing going out, I don't know if this is a true fact. I was also thinking that maybe the tail shaft output bearing could be bad causing this vibration? If anybody else has had this problem please let me know!

If anyone could help me out with this that would be great. I can't drive the car with this vibration!!!! Thanks in advance for your help!

 

well first. (may sound stupid) did you check the wheel balancing? but, more likely, did you check the slip yoke attached to the output shaft? any play in that peice will give you that kind of vibration

 

he did put new wheels on the car over the winter but the vibration was there last summer also so, any other info would be great guys

 

also, if you have stock rubber motor mount and have a poly tranny mount, all the vibrations are coming to the transmission and then causing you to feel that shakes there instead of from the engine.

 

ahh didnt think of that yet

 

The vibration was there before I put in the poly Trans Mount. I thought that maybe since my trans mount was bad that it was causing this issue!

 

You always have to balance the driveshaft whenever you swap out U joints. This has happened to mine, and another of my friends' cars. It should cost around $50 to have it balanced. Even if it "looks" perfectly centered, 99 times out of 100 it isn't. Go spend the money on that, because it needs done, and hopefully that eliminates your problem!

 

Good deal! I am going to have it balanced first thing in the morning! Thanks!

 

Good deal. Let me know if that fixes it.

 

im kinda confused because i have also been feeling a vibration but it only happens when my converter locks up on normal throttle which is at 50 mph at first when i had my 3000 it would lock up at 40 nice and smooth but then one day all of a sudden once it locked it started vibrating like crazy so i thought my converter was done, so went ahead and switched to a new 3200-3400 and bumped up my lock-up to 50 and it was still vibrating so now im thinking its something to do with my rearend or tranny but its pretty wierd that it only does the vibrating when it locks up ?????

 

I am having the same problem lol! I had the scanner hooked up after a new exhaust install checking A/F. I made a couple WOT runs, then started back home the converter locked up and damn this thing was vibrating crazy! Got home checked it out...couldn't find anything. I am confused about this also. Let me know if you find anything.

 

^^^ You guys may want to look at yours also!!^^^

After more investigation and test driving it was also happening around 40-50 mph really bad right around 4th gear and lock up!


Well i found out what my problem is, the out put shaft bushing in the trans housing is wiped out!!!! I posted a video (it a $hitty cell phone video). It has about 1/2 of play on each side!



http://www.youtube.com/watch?v=x-MF25G_T9U

 

Glad you found the problem!