Bad vibration in 4x4 under acceleration

[2003trailext]

this seemed to happen only after I replaced transfer case fluid, tried to take off driver side strut and the axle popped out at the joint/boot about 3 weeks ago. i also replace tires up front with better used ones(doubt if its tires). prior to all this I had and alignment done and my old tires were wearing unevenly so i got a realignment. From what I recall everything still seemed find until about 3 weeks ago. I cant recall exactly but it seem to happen after i changed my transfer case fluid. either way my tb as been on marks 2.5 lift, blistien hd,stock springs up front and z71 springs and rancho shocks in the back. 1.5" wheel spacers and 265/70/17 since i started driving it 4 months ago. we have had a lot of fun in the snow. somebody made a comment why would one be cruising in 4hi. i personally would like to cruise in 4hi in snowy and heavy rain conditions. I feel safer knowing all my wheels are trying helping to keep me on the road in bad weather. Im mad that i cant use my 4wd without this dreaded vibration. it seems to happen to me at any speed and as soon as 4wdhi is switch to 2hi it stops.

[Bacnbit]

this seemed to happen only after I replaced transfer case fluid, tried to take off driver side strut and the axle popped out at the joint/boot about 3 weeks ago. i also replace tires up front with better used ones(doubt if its tires). prior to all this I had and alignment done and my old tires were wearing unevenly so i got a realignment. From what I recall everything still seemed find until about 3 weeks ago. I cant recall exactly but it seem to happen after i changed my transfer case fluid. either way my tb as been on marks 2.5 lift, blistien hd,stock springs up front and z71 springs and rancho shocks in the back. 1.5" wheel spacers and 265/70/17 since i started driving it 4 months ago. we have had a lot of fun in the snow. somebody made a comment why would one be cruising in 4hi. i personally would like to cruise in 4hi in snowy and heavy rain conditions. I feel safer knowing all my wheels are trying helping to keep me on the road in bad weather. Im mad that i cant use my 4wd without this dreaded vibration. it seems to happen to me at any speed and as soon as 4wdhi is switch to 2hi it stops.

This is just to make sure. Did you put the correct fluid in the tcase? (GM Automatic Transfer Case Fluid, GM PT# 12378508 The Blue stuff). We have had to reservice multiple units that folks have put the wrong stuff in and after cleaning and changing it takes up to a 100 miles for the tcase to start functioning correctly again. sounds weird. But have seen it.
Also lets look at that statement about the axle popping out at the joint. Did it come completely out of the tripod? If it did it may not be back in the same position it was removed from causing vibrations. Seen that one too. All just food for thought. Hope you can solve it. I get ya on the 4wdhi in the snow.

[2003trailext]

this seemed to happen only after I replaced transfer case fluid, tried to take off driver side strut and the axle popped out at the joint/boot about 3 weeks ago. i also replace tires up front with better used ones(doubt if its tires). prior to all this I had and alignment done and my old tires were wearing unevenly so i got a realignment. From what I recall everything still seemed find until about 3 weeks ago. I cant recall exactly but it seem to happen after i changed my transfer case fluid. either way my tb as been on marks 2.5 lift, blistien hd,stock springs up front and z71 springs and rancho shocks in the back. 1.5" wheel spacers and 265/70/17 since i started driving it 4 months ago. we have had a lot of fun in the snow. somebody made a comment why would one be cruising in 4hi. i personally would like to cruise in 4hi in snowy and heavy rain conditions. I feel safer knowing all my wheels are trying helping to keep me on the road in bad weather. Im mad that i cant use my 4wd without this dreaded vibration. it seems to happen to me at any speed and as soon as 4wdhi is switch to 2hi it stops.

This is just to make sure. Did you put the correct fluid in the tcase? (GM Automatic Transfer Case Fluid, GM PT# 12378508 The Blue stuff). We have had to reservice multiple units that folks have put the wrong stuff in and after cleaning and changing it takes up to a 100 miles for the tcase to start functioning correctly again. sounds weird. But have seen it.
Also lets look at that statement about the axle popping out at the joint. Did it come completely out of the tripod? If it did it may not be back in the same position it was removed from causing vibrations. Seen that one too. All just food for thought. Hope you can solve it. I get ya on the 4wdhi in the snow.

yes its was the blue stuff bought straight from gm dealer. they had the acdelco branded one.
yes it came completely out of tripod and i was thinking it might not be in same position as well.
thanks for reply

[2003trailext]

replaced wheel bearings, 4wd disconnect and cv axle. still have this problem. im looking for some tires now. after i get some i will get a alignment. it would be nice if thats all it was.

[2003trailext]

just giving update. my passenger side axle wasnt in disconnect all the way. prior to me changing disconnect it got bad to the point where it was making alot of noise. so my vibrations came from the axle not being in disconnect all the way and (before replacing stuff) i would say having bad disconnect bearings allowing more play in axle part going into disconnect. hope this helps other further pin point there similar problems

[Craig]

I know this post is been down now for some time, however I am curious if people having this problem have replaced their disco with the AWD sleeve and if so did that seem to help at all?

[HawkeyeC25]

Lots of us have done the AWD Sleeve swap (myself included). It's usually not a fix to any issue besides a failing fork You should find a lot of info using the search function on the site for this topic.