I jus put new u joints on my front driveshaft and when I got it locked in 4x4 it vibrates bad. Any ideas? Also I think I need to rebuild my TC. I just put new tranny in about 2 months ago and I checked tc fluid today and its dark and smells burnt. Any links to rebuild kits? Its a 231 DHD. Thanks

 

Check that the front u-joint is fully seated in the yoke.

Did you replace the joints in the cv joint as well? (double-cardan joint, whateveryawannacallit) There's a spring an ball that goes in there as well. If you don't reassemble it just right, it WILL give you a vibe.

Drop the rear driveshaft, pull the tail housing off the t-case, and check and see if the snap-ring that holds the rear bearing in place is still there...... if it isn't, do a search on "Transfer Case Saver". It replaces the snap ring, and is a MUCH better design.

Before you drain your t-case, make sure you can get the fill plug out.

 

I jus replaced the front one. I checked the tc snap ring before I had my tranny rebuilt.

 

Did you take the driveshaft apart? (at the splines?) If so, you need to make sure that the ujoints line up correctly.

 

Also did you assemble everything the same way it was taken apart? if the yoke was rotated 180 degrees when it was reassembled it could cause a vibraation.

 

So where the u joint goes into front axle I have 180 degrees off? The driveshaft is flat and has 4 bolts that bolt to the tc, cud I have that 180 degrees off?

 

It should be balanced...and therefore, no vibration.

 

You have 3 U jouints in your front axle. The one by the transfer case being a double cardon joint (as mentiontioned by HeyYou) having 2 U joints. The third down by the differential. The problem is, when a driveshaft is installed by the factory, it is 'phased' (as they call it in the ASE books) and that is the way the driveshaft is balanced. So if you take the driveshaft apart to replace the u joints and it not 'phased' or realigned properly when you reinstall the shaft, it will become unbalanced. Hince your dilema. I would think if you take it to a driveshaft specialty shop to have it rebalanced, it should be fine. But next time you do U joints, make sure you mark the location and direction of everything before you take it apart.

 

I hope that makes sense to you as it is the best way I can explain it.

 

I forgot about the double cardon thing! That does make a difference....

If the vibration is caused by this it will cause problems so it needs to be fixed.