7/19/23 New edit!!! Truck is fixed! Was the axle

Hello all.

So I have an 07 that vibrates (like a driveshaft vibration on D2 etc. ) but it only is noticeable when I am accelerating. The harder I accelerate, the worse that it is.
The vibration is NOT there when coasting or being real easy on the throttle.

History: New right front hub installed in Feb.

She has the famous transfer case wine

Forward output shaft seal on the transfer case IS leaking.

Center carrier bearing appears ok.

Scary **** I found and did:

1 bolt missing from front ds at the t case and another very loose. The hardware has been reused from about 7 months ago I took off the front ds checking for something else.
I have since tightened the loose bolt and replaced one bolt with a grade 8.8 bolt (temp fix...waiting on new oem hardware).....Vibration is still prevalent. No improvement.

Checked hubs by shaking tires method...they all seem fine.

My hypothesis is that the loose bolt and missing bolt definitely created part of this problem and probably caused my t case seal to leak.

However, since tightening the bolts had no effect, I think this coming from the transmission side.

any ideas?

 

My idea: All the **** you just listed above.

 

Well an update: rear drive shaft missing a bolt, and carrier bushing IS bad. I didn’t


see it before

ordered new 2 piece bushing from JXB and getting some more hardware from the salvage yard and going to use red loctite

 

I tend to just recommend replacing the shaft. Because if the center support is torn then usually the bering itself is on the way out and the joints are definably worn. Anything besides replacement is a temp fix. But if you don't trail hard, then really you may be okay for some time. A new GKN (OEM) shaft is $450 shipped from the UK and I think for a critical item is the ideal way to fix it. Just my 2 cents tho.

 

Well I replaced the center support with the JXB performance unit. Used the street (soft bushing) and it has reduced the vibration quite a bit but there is still some present on acceleration.

 

Update: I replaced the rear drive shaft and it go rid of the vibration from under the seat. The old drive shaft bearing seemed ok but I noticed it was out of round slightly.

BUT NOW,
I feel a slight vibration in the front end instead of under the seat...so now i'm going to chase that.

This time the vibration is more akin to cupped tires feeling. But it doesn't do it while coasting. And yes, it is more prevalent on heavy acceleration which leads me to the torque converter thing idk if that is an indicator of that famous issue.

Has anyone had to replace the rear transfer case mount? Mine is oil soaked of course and I can't tell if its collapsed or not.

 

updating this only because I hate to see unresolved threads....this is not resolved yet.

I replaced the driver side cv half shaft.

Now there is a cv style clicking when driving straight. and a vibration on deceleration.

I am going to remove the front drive shaft (which there is no guidance on so I have to remove the exhaust apparently) and see if I can tell if the joints on it are bad or something.

 

Thanks for the update - really appreciate it. I wanted to add too that one way to get a clue if the torque converter might be an issue is to observe lockup status with a scan tool while driving it.

 

If you replaced a CV and now have CV clicking, would not the new CV be suspect? I have a hard time believing vibration on decelerations would be from the front drive shaft unless it is somehow severely compromised (bent, etc) - in which case I would also think it would be more an issue under acceleration.

 

Ditto what Dakota said about the new cv axle. Aftermarket ones can be... problematic, if that's what you used.
By the way, Dakota, what brands of cv axles have you had good luck with?