differential failure

[Regulator1175]

Tuesday night we were on our way to pick up dinner for my oldest daughter's birthday and we came to a rather rapid stop from 65mph in the middle of the highway. She got the truck into the center median, we were in the left lane and couldn't get over to the right, and I got out and checked it out. It would move forward with some gas, but the tire was obviously binding up on something. It would not back up at all.

So I got on the phone and got roadside assistance on their way out to get me, and Tracey had my brother come down and get her and continued on to get food while I waited with the truck. I asked for a normal tow truck, seeing the obvious problem that if it went up on a flat bed it would be a bitch to get off. What showed up, a flat bed truck. He told me that it would be another hour before they could get anything else out so we just went ahead with that truck. Got the truck back to the house and spent 30 minutes trying to get the Bravada off the flat bed without hitting any of the other vehicles in the drive.

I didn't have any time on Wednesday, however got into it on Thursday. My initial guess was the front differential. Sure enough when I started tearing it down it was pretty obvious that I was correct. When I pulled the half shaft I got pieces of gears with it, I don't think that is supposed to happen.

Unfortunately at this point I am seriously hurting for money, and this repair is far down the list. I pulled the half shaft on the drivers side as well, and she now has a 2 wheel drive Bravada. It will get her around atleast, so I am going to call that good enough for now.

Any suggestions on a fuse or relay to pull to ensure the TC doesn't kick in? I want to avoid any further damage inside the differential if I can help it.

[SteveTB03]

If the damage is in the differential why don't you just pull the front driveshaft out?

[TangoBravo]

h

[bartonmd]

You'll want to take the front prop shaft out of the T-case and front end, or it's still going to try and drive the front differential...

Mike

[Regulator1175]

If the damage is in the differential why don't you just pull the front driveshaft out?

You'll want to take the front prop shaft out of the T-case and front end, or it's still going to try and drive the front differential...

Mike

I was kind of afraid that was going to be the answer. It means getting into something I have no experience with. I don't mind learning, and am pretty good at figuring it out as I go, but its 15* outside and I don't want to freeze my ass off laying in the snow and ice. I was hoping for a simple "pull this fuse" solution.

[mikepeters1983]

If the damage is in the differential why don't you just pull the front driveshaft out?

You'll want to take the front prop shaft out of the T-case and front end, or it's still going to try and drive the front differential...

Mike

I was kind of afraid that was going to be the answer. It means getting into something I have no experience with. I don't mind learning, and am pretty good at figuring it out as I go, but its 15* outside and I don't want to freeze my ass off laying in the snow and ice. I was hoping for a simple "pull this fuse" solution.

If it was simple then it would be no fun lol

[The Roadie]

I thought the Bravy uses front fuse #8 for the TC same as the rest of us. There may be a separate one fopr the encoder motor. Have to cnech in a few hours when I get to my manuals.

[bartonmd]

I thought the Bravy uses front fuse #8 for the TC same as the rest of us. There may be a separate one fopr the encoder motor. Have to cnech in a few hours when I get to my manuals.

Even if it's not working the clutch, I thought it always transferred ~20% torque to the front, or something? i.e. I am under the impression that even if everything is disconnected, the front still gets enough power to spin the prop shaft?

Mike

[The Roadie]

Ahhhhh, it's like 5% torque, but you're right. You'd have to pull the encoder motor and rotate the control shaft to zero torque transfer.

Far easier to yank the driveshaft.

[teebes]

Gatorade caps anyone? I'm running a special for the holidays.

[DJones]

What would cause a differential failure like that? I would suggest yanking the driveshaft too, because you may need it out of there for the repair anyways.

[bartonmd]

What would cause a differential failure like that? I would suggest yanking the driveshaft too, because you may need it out of there for the repair anyways.

Likely a pinion or carrier bearing... On a 4WD model, I'd say also possibly spider gears, as they run all the time when in 2WD, but since he has no splined disconnect, I would say probably not...

Mike

[Regulator1175]

Sorry I haven't gotten back here to answer questions, life has been a bit hectic.

When I pulled the half shaft there was no oil in the diff at all. Obvious root cause of the failure. We purchased this truck about 20k miles ago, and I was assured all the fluids were changed. In fact the TCCM had to be serviced before I bought it because the truck was stuck in 4 hi, and was hopping when we tried to take it out for a test drive. Not to be the one to trust anyone, I did go through the entire truck and all the fluids were good and did look like they were new. I have had no loss of fluid on the driveway, so my only assumption is that it was throwing oil from the half shaft seal while driving.

In any event, I can stick my finger into the diff and can feel loose and broken pieces of gears, so I am sure a rebuild is going to be interesting. There is no visible damage to the case, so it should just take a rebuild. Fingers Crossed anyway.

[Zero]

best of luck buddy, here to hoping it wont cost and arm and a leg

[MD_trailblazer]

This same thing just happened to me as I just finished replacing my transfer case and I found out my front diff is messed up as I can move my drivers side inner cv joint likes it's nothing moves couple inches to each side just like his problem but how much is a rebuild kit for these?

[MD_trailblazer]

I need help on this as I need to know if it will be ok to drive my truck with just the three 18mm bolts holding the wheels on on each side

[The Roadie]

I need help on this as I need to know if it will be ok to drive my truck with just the three 18mm bolts holding the wheels on on each side

If you mean the 18mm bolts that hold the wheel bearing assy into the steering knuckle, it will be perfectly fine because that's all the 2WD vehicles have up there. The CV shaft nut doesn't add a lot of strength to the bearing.