I dropped the front DS on my 99 after it started to fail.
I drove it awhile with the center diff locked with no problems.

My issue started after I changed the tcase fluid. I used Mobil1 75w-90(I know I shoulda gone heavier). I had a case on hand though so why not. Anyways after changing the fluid I started getting a vibration when going over 65mph. Keep in mind this is while the DS is removed.

I'm pretty sure I filled it completely full. Could low oil cause a vibration or is there anything else I should look at?

 

Output bearing possibly? Have you checked the flanges to see if there's any play?

 

I have not! What's the best way to check for play? I'm not clueless I just know some methods are better than others.

Is it not a bit weird I didn't have this issue until I changed the fluid though?

 

Could be a coincidence, but how long did you drive without a front shaft? I recently developed a similar issue after driving without a front driveshaft, not sure if it was related as I did go to conclave and beat my truck pretty hard on the trails.

 

I drove a good while without it. Probably +3k since it's not my DD my younger brother drove it to and from school for awhile, but never over 45mph.

He's a new driver and unlike myself has never broken a rule, and actually turns his phone off while driving. I know you don't care about him but I thought I should clarify how cautious he is and that he didn't abuse it, before someone jumped in with those accusations.

Have you solved your issue? If so how?

 

Haha well I wouldn't say I don't care about him... he's a human.

But that's besides the point.


No I have not, I'm about to fix a motor mount and I'll probably check out the t-case when I'm under there.

 

wait a second....is this your brother????



I love that guy

 

output check = drop shaft make sure nut is tight (center nut on flange). push up and down and all around. it should only spin.

 

Pretty close!

And I'll give that a try dusty. Hopefully the nut is just loose.

Keep me posted on what you end up finding out Zack.

And thanks for the input guys!

 

I've had a vibration over 65 since I got the truck. It seems to come and go, and so far I've had no luck at all diagnosing it.

I sorta think it's a bearing, either wheel or in the diff. The big difference is mine seemed to go away when I pulled the front shaft. I thought it was the shaft, but with a different drive shaft it's doing a similar thing. And because it seems to be intermittent it's hard for me to believe it's the shaft.

In your case, I'd start with rebalancing the front tires.