NEED HELP! Bad Vibes in 4WD

I've got a bad vibe, more like a shake, that seems to be coming from the front end somewhere. It shakes the truck bad when 4wd is engaged, then goes away in 2wd. I am fairly certain its coming from the front diff or shaft extension, but could be the T-case as well. ???

I took it to a shop that said it was the front DS, so i had that straigtened/rebalanced by my Driveline shop with no change or improvement. The same shop also recently rebuilt my rear DS, so its good. I have also replaced both CVs hoping it was something simple like that but no change in vibe.

It is now at another shop and they can't find anything wrong. Next step is tearing the diff apart, but he is hesitant because he doesn't want to do all that and not find something because it will not be cheap.


Anyone had any similar issues? Any suggestions? Please help
Im losing my damn mind

 

https://www.tacomaworld.com/threads...differential-bearing-vibration-thread.152173/

TSB or do the ECGS bearing.

 

My bad. I should mention I've got 4:88s and an ARB locker. So there is no needle bearing.

 

Ah well, if only it had been that simple!

 

Belive me, i wish that was the case

 

subbed in case I need it for future reference... hope I don't though. I've got the same gears and locker

 

I wonder if it's the bearing in the shaft extension. Did you see if there was any kind of play when you changed CVs

 

Just a guess but unbalanced front drive shaft?

 

Sorry dick didn't see that.

 

Looked fine, but its hard to say.

I'm wondering if it may be the other end. It's got a weird gear and shaft system(not sure what it's called) that connects it to the clamshell. Maybe something is fucked up in there?
Here's some pics from the spare i have

 

Had that overhauled. Would have been nice if it was that though

 

Could the flange on the pinion or transfer case be warped?

 

Dunno. He said visually everything looked good there, but I'll have him check.

 

Not sure how that gear on the clamshell side is secured, but it could be what's securing it. You could swap shaft extensions since you have a spare. Other than swapping front riffs completely, not sure what else it could be.

 

My thought as well. I feel like if it was in the diff there would be some sign of metal or damage in the fluid. It was clean.
Worth a shot before tearing the diff itself completely apart.

 

You just pry it out with two screwdrivers and tap it back in evenly. The stub shaft

Edit- There's a c clip at the bottom of it. Just like the inner cv

 

@tacomgee are you having a shop pull the clamshell if needed? If you do it yourself and want some help, hit me up!