Horrible vibration. 4 bolt swap, and car has been sitting

[steve]

Remember that the MT and AT rear diffs have different gear ratios. Make sure you have the right one.

 

[Momar]

Remember that the MT and AT rear diffs have different gear ratios. Make sure you have the right one.

Ya, I have thought of that, but I would not think that it would roll at all hardly if the front and rear had different ratios.

 

[steve]

It does right up to the time you burn out the VCU in the center diff.

 

[Momar]

It does right up to the time you burn out the VCU in the center diff.

Welded center diff.

 

[evo9mrtt]

Check your intermediate shaft and its bearing. I know it's a long shot but sometimes the mount comes off the back of the block or becomes loose and can cause some crazy vibration! I recently had mine come off while on the highway and it made the car vibrate horribly! After I replaced both bolts and got it buttoned back up it drove better than it did when I bought it. 10 fold!

 

[Momar]

I actually had that happen on a highway trip before. It was different. This feels more like it is the rear or middle of the car. I will double check it though. Like I said the only driveline thing that I changed was the 4 bolt swap. I would think it about has to be the diff, but I dont find any slop in the pinion like I expected. idk.

 

[Momar]

I swapped a different 4 bolt differential into the car and it fixed the problem. I haven't taken the diff apart to figure out what the problem was, but it was definitely something with the diff. And a positive, is that the lsd is functional in this one too, so fixed 2 problems.