the other day i was going down a trail and engaged 4wd every thing was fine until i got off the trail and put it back in 2wd. Now any thing above 25 mph results it a grinding and vibrating noise so bad it drowns out my radio and vibrates my mirrors to the point of not being able to see out of them. i have tried putting it 4wd to see if that helped any thing and it just made it worse. the grinding/vibrating still occurs when i put it in neutral both ax-15 and t-case.

my jeep has:
95
ax15
1" t-drop
3.5"lift
d30 front axle
c 8.25 rear
np231 t-case

if you need any thing else ill get it for you
and thank you very much for your input

 

Interesting.... I did the Vacuum bypass for my front D30. I had the part time system with a 231 T-case. While traveling at highway speeds I got this really gnarly grinding sound. It went away when I threw it in 4wd, and promptly came back when switching back to 2wd. After switching between the two in rapid succession the sound went away, and I haven't heard it since. I wonder if it is a bad bearing in the T-case? I know dill about it though, I am new to Jeeps. Hopefully someone comes along with a good answer, maybe my experience is related to yours?

 

ive seen a couple of other 4x4 do the same thing because the auto hub was still partially locked in, try putting your jeep into 4 low the put your trans into nuetral , put back into 2 wheel the back your jeep up about five feet then put into drive. i always take mine out of four wheel like that and have never had any problems, but that should disengage it!

 

Vacuum actuated front axles went away in 91 or 92 IIRC.

 

Could I have blown my case or front diff?

 

Sure. Jack it up and rotate some tires. Look at driveshafts, axle u-joints and driveshaft u-joints. Inspect fluid levels and condition. Unfortunately we can't see or hear your Jeep from here.

 

ill see if i can get a video up here of it. u-joints are fine no play in any of them plus i just changed them.
i do have a blown main shaft output seal would this cause this kind of issue

if my front diff was blow wen i pulled the cover it would have been noticeable right?

 

i think i may have found the problem its my front drive shaft. it apparently has shifted in an odd angle and is smacking up against the adjustment bracket for the t-case pics to come

 

just figured i would let you guys see what happened to my d-s this is what it looked like when i pulled the u joints out

 

Interesting what you find when you crawl under and have a look..............

When's the last time that driveshaft was lubed?

 

hell if i know thankfully i have a spare