Something BAD happened today

[SSt4r]

Not good, something broke but not sure what yet...

Drove to work today and in the process of parking, I engaged reverse and tried to accelerate. There was a loud bang or pop & then the grinding. It would not move. I was able to roll back into a space and engaged park. It would not hold in park on a very slight hill; it rolled with a little notchiness. Put in drive again and no movement but loud grinding. Engaged center diff lock and it would move with no noise (I only went a couple feet forward then back again). Sound seemed to be from the center of the vehicle.
I had someone look underneath when I engaged drive and he saw the front driveshaft spinning with loud grinding; still no movement of the vehicle though.
I'm thinking not transmission but any suggestions?
Close to 150,000 no prior driveline issues, center diff lock & Lo range have been engaging fine. Didn't try to engage Lo today.

 

[RonJR]

Sounds like you stripped some teeth in the front diff. Root cause is hard to speculate on; perhaps the ring-pinion spacing was too large for some reason. Differentials are weaker in reverse than going forward, so if you goosed it hard in reverse and the spacing was excessive, it could have stripped some teeth.

Another possibility is a broken CV joint.

Engaging the center diff lock allows you to send torque to the rear wheels even if the front is free-wheeling, which enables you to move. I wouldn't drive it much that way, though, since there very likely are loose pieces of metal up front in places where they shouldn't be.

 

[alia176]

Dude, it ain't that bad. Tow it home, then start with the front CV axles. Do the wiggle test to see if it's one of the CV axle and if not, it might be the front diff.

When put it into drive you noticed the front DS spinning. Now, see if one of the front CV is spinning in place. If so, the spinning CV axle is broken somewhere.

 

[SSt4r]

Guys, thanks for the info. so far. Will check the CV joints.

RonJR, I did goose it in reverse with the wheels turned. If I destroyed the front diff, wouldn't I still get some torque to the rear to move?

 

[swampdodo]

Not without locking the center diff I think. Center diff is normally an open diff...so like current, torque takes path of least resistance.

 

[SSt4r]

Okay, thanks again all. Had helper check again & left front 1/2 shaft was spinning with truck stationary (outer CV joint failed), so hopefully that's all I need!
Gonna just research quality CV joints now.

 

[Jeffy]

Okay, thanks again all. Had helper check again & left front 1/2 shaft was spinning with truck stationary (outer CV joint failed), so hopefully that's all I need!
Gonna just research quality CV joints now.

https://www.cvjreman.com/cv-axles/

 

[alia176]

Okay, thanks again all. Had helper check again & left front 1/2 shaft was spinning with truck stationary (outer CV joint failed), so hopefully that's all I need!
Gonna just research quality CV joints now.

well, the best quality is OEM if you can swing the $$$$. Otherwise, a $80 reman unit from NAPA and the like with lifetime warranty will do ya! Seriously, if you're not running 35s and wheeling the snot out of it, I don't think it's necessary to spend oodles of money on CVs.

 

[crimedog]

I have had good results with the NAPA axles on both my 3rd gen and now 4th gen. However, the re-manufactured axles have given me issues with leakage around the seal. I always change the seal. Apparently whoever re-surfaced these axles got a little crazy and they took too much material off to maintain a good fit between axle and seal. This has happened twice.

I have used the new axles without any issues. They are only about $20 more and haven't had a problem. I do not have big tires or a lift, and I don't off road a lot, so your experience might differ.

 

[alia176]

I have had good results with the NAPA axles on both my 3rd gen and now 4th gen. However, the re-manufactured axles have given me issues with leakage around the seal. I always change the seal. Apparently whoever re-surfaced these axles got a little crazy and they took too much material off to maintain a good fit between axle and seal. This has happened twice.

I have used the new axles without any issues. They are only about $20 more and haven't had a problem. I do not have big tires or a lift, and I don't off road a lot, so your experience might differ.

I agree, NAPA has brand new CV axles for not much moola and they seal tightly. In fact, I tried to take one of them apart so that I can redo the boots to no avail. I've dropped them from a tall ladder, talked dirty to it, talked nice to it, cussed at it. Nope, wasn't gonna come apart. That MoFo.....SOB.......