4wd Noise HELP!!!

[88chevota]

I have a SM456 tranny to NP205 t-case. when I am in 2wheel drive everything is perfect. When I go into 4 high and hit 3rd gear it starts to make this weird rattling noise, almost like it is trying to pop out of four high, but it stays in fine. I am not sure if it is the t-case or not. Here is were it starts to ge weird. I take out the d-shaft and no noise smooth as ever. put back in the d-shaft, lock the hubs and leave it in 2wheel no noise. only makes noise when 4wheel is engaged with d-shaft in. (does not matter if front hubs are locked or unlocked still makes noise) What the heck. Anyone have any ideas? d-shaft appears to be in good condition. I even regreased it.

 

[rover67]

i am having the same problem.

i am currently in the middle of a 3000 mile trip with the truck and plan on trying to take the tranfer case apart when i get back home to denver. PLEASE PM me if yo ufigure it out... i'll do the same.

 

[CruisinFJ60]

sounds kinda like the front output bearing may be a little loose and only vibrates enough when the transfer is engauged

 

[mtnfj]

T-case noise

I had a similar problem that showed up about a month ago. I don't know if it's the same on SM/NP configuration but with my 83 stock trans and t-case, the seal between the two fails and the fluid in the t-case flows into the trans, leaving the t-case dry and burning up the bearings. I replaced the trans and t-case because it was easier than spitting the t-case and going through the brain damage. If need be, I can go into more detail (ended up paying $200 for the trans/t-case and $450 for install).

 

[mudpig]

having similar problems...... very noisy and clunky in 4wd..as long as hubs are in. by rotatng the front outputu shaft by hand u can feel the clunking and vibration on the front of the t case... im thinkin bearing...whats involved in fixing it can it be doen in situ???

 

[88chevota]

I am not sure it is that front bearing in the t-case. Everything seems to be just right in the t-case. My front diff has a decent amount of slop though. I took it for another drive and it only does it when I let of the gas. Weird... It's supposed to snow tomorrow so I won't be able to look at it until the weekend. I get back to you all when or if I figure it out.

 

[88chevota]

I still can't figure this out!

I think i have narrowed it down. I changed out a portion of the d-shaft and it still does it. It does not do it in 4-low though.

I am going to order a bearing and seal kit for the t-case so that should do it. It sure sounds like it is in there the more I listen to it. I think it could be the needle bearings inside slopping around.

I'll report back when I get it done.

 

[88chevota]

ok so I was going to order the t-case rebuild kit and I was telling the guy my problem and he said I should look at the front diff and the shift fork slider.

I hate the front diff!!! I wish it has an inspection cover! anyone converted one to an inspection cover?

 

[Turkeypen]

I have the same issue, and for what its worth, I'm going to drop the front shaft and tighten the Pinion Bolt as a first step.

I am following this post and hope you discover the source!

 

[88chevota]

I have the same issue, and for what its worth, I'm going to drop the front shaft and tighten the Pinion Bolt as a first step.

I am following this post and hope you discover the source!

I did that already. I have tested just about all I can. Now it is time to start taking something apart.

 

[88chevota]

Finally!!!!! Thanks to some good buddies who helped me take a good look at everything it is finally fixed. It was a combo of things all in the front driveshaft! Angles were bad, shaft was way out of balance, and the splines were sloppy. I bought me a double cardan from a 85 mini and had it mated to a good cruiser shaft with good splines, got it balanced. I put it in today and drove it. I love it when the only thing I hear is the rumble of the V8. Problem solved. Good luck to all the other guys who are experiencing the same issue.

i thought I had checked everything, I turned, pulled, pushed, tugged to see if anything was loose except at the splined part of the driveshaft. Took someone else to look at it. He just grabbed the splined area and pushed up and down and the thing slopped all around.