4WD woes

[NWPA Jeepy T]

97 Sport 5 sp
4" lift 35s
4.56 open hp30 front, Detroit 44 rear
Sye

2wd everything drives like a dream.
4wd, straight is fine, but when turning a 90° corner, there's a howling/grinding sound.

Wheel bearings and all axle shafts/joints are brand new

Rear diff rebuilt 11/23 with the locker
Front diff rebuilt 8/24 from damaged teeth from a bad pull

Any ideas? Am I into something bad in my diff or a t case rebuild? I thought about swapping my front driveshaft with my son's just to rule it out

I'd really appreciate any help.

 

[rasband]

I'd probably put a camera underneath to try to isolate, or put the whole thing on jack stands and see if you can reproduce it as safely as possible. Otherwise it's isolate and test.

 

[NWPA Jeepy T]

I'd probably put a camera underneath to try to isolate, or put the whole thing on jack stands and see if you can reproduce it as safely as possible. Otherwise it's isolate and test.

We tried with the jack stands, but it only happens on road, under load.
The camera is a thought, though

 

[rasband]

We tried with the jack stands, but it only happens on road, under load.
The camera is a thought, though

That definitely sounds bearing related. Swapping drive shafts is a quick and easy test.

 

[NWPA Jeepy T]

Diff bearings or t case? Only happens when turning in 4wd

 

[rasband]

Diff bearings or t case? Only happens when turning in 4wd

How would any of us know? You could at least upload a video to youtube and give us a link. But just because the ujoints and hubs are new, I wouldn't rule them out. If the torque is wrong or the ujoints were installed poorly or incorrectly - they could easily be to blame.

 

[Link]

Take the front driveshaft off or at least unbolt it from the front differential and SECURELY, strap it up. Do NOT turn the 4x4 on if the driveshaft is strapped up! Then perform the same driving tests. Report the results.

 

[rasband]

Are you driving 4wd on dry streets or wet/dirt/loose?

 

[NWPA Jeepy T]

It's dry now, but this started right after Thanksgiving when we had gotten close to 48 inches of snow in 48 hours. I'll work on the video idea and report back on the front DS test

 

[NWPA Jeepy T]

How would any of us know? You could at least upload a video to youtube and give us a link. But just because the ujoints and hubs are new, I wouldn't rule them out. If the torque is wrong or the ujoints were installed poorly or incorrectly - they could easily be to blame.

New Timkin hubs and 10 factory shafts. The shafts were preassembled and I torqued everything to spec when I installed. It was doing it before all the new stuff in Dec and again yesterday. I had just asked about which bearings because I don't understand the 4wd forces on different parts, so I thought someone might have input based on experience. I'll work on your suggestion though

 

[NWPA Jeepy T]

Video was inconclusive, so today I pulled my front driveshaft, checked all the joints and both diff & TC yokes and everything looked good. Moved to the rear & as I was loosening the TC yoke bolts, I noticed the yoke retaining bolt looked weird. Pulled the drive shaft & the rear yoke bolt was almost completely off, allowing the whole rear output shaft to move in & out about a half inch. I'll get that torqued down tomorrow, grease the driveshaft splines, reinstall & hopefully beat this for free!!!

 

[rasband]

Video was inconclusive, so today I pulled my front driveshaft, checked all the joints and both diff & TC yokes and everything looked good. Moved to the rear & as I was loosening the TC yoke bolts, I noticed the yoke retaining bolt looked weird. Pulled the drive shaft & the rear yoke bolt was almost completely off, allowing the whole rear output shaft to move in & out about a half inch. I'll get that torqued down tomorrow, grease the driveshaft splines, reinstall & hopefully beat this for free!!!

Yikes, even if this isn't the culprit (though it sounds like it is) I am really glad to hear you found this before something really bad happened!

 

[macleanflood]

I'd check your diff fluid for what's left of your ring and pinion.

-Mac

 

[NWPA Jeepy T]

I'd check your diff fluid for what's left of your ring and pinion.

-Mac

Not on the diff end, it's on the t case end. I checked fluid in different, t case & tranny Friday, just to rule out the cheap, simple stuff. All were mostly good with just s tiny bit of top off here & there