Driveshaft dropped off and caught fire... is it totalled?

[slamgranderson]

I was driving today when I heard a loud whine coming from underneath the jeep. I kept going for a bit and then it got worse and right as I was pulling off the highway i heard a number of clunks, and the car stopped moving. Got out and theres a fire on the rear differential. The driveshaft is completely disconnected from the read diff. I'm in CA on a road trip and am supposed to be in Colorado in a few days. I paid 3,000 for the jeep and it has 120k miles. I'm wondering if anyone may know about how much the cost of repair may be and if it exceeds the value of the car, in which case I'll have to junk it and get a rental and keep moving. Because its sunday the garage where I towed it won't be able to check it out until tomorrow but I'm wondering if it's even worth it to pay for an inspection.

Any thoughts?

 

[LibertyTC]

Wow..Sorry to hear about the catastrophic failure of the 8.25 rear diff and potential damage to the dive shaft?
Did the fire cause anything else to melt under the jeep? Is yours a 2004 with a trac-lok rear end?
Photos would be helpful.
The first most important question is where is the closet junk yard you could find KJ parts at?
If it is just the rear diff without damage to dive shaft, it may be repairable somewhat quickly.
On road in a hurry and your pressing schedule, makes your choices difficult.
The shop may sympathize with you to at least give you a quick cost summary of damage, and a decision may have to be made by you, right there & then.
Post back what happens please...

 

[Aceofspades]

Get a rental and fix the jeep?

 

[HoosierJeeper]

Ujoints probably failed. I'd fix it and keep going. 120k is young for a KJ.

 

[JasonJ]

Ujoints probably failed. I'd fix it and keep going. 120k is young for a KJ.

Agreed... doubtful it's permanent damage. A rear diff fire is kinda rare as it is... clearly something locked up and got too hot, likely then ignited grease on/near the rear diff, or the fluid inside. With the driveshaft dropped off at the rear axle, would almost have to be rear u-joint. Next question is, did it screw up the yoke on the driveshaft too?

 

[Billwill]

I would open the rear diff to inspect it for damage and yes definitely check to see if it is a trac loc diff and needs the Mopar friction additive.

 

[slamgranderson]

I didn't get a chance to take any pics before they towed it away, but essentially the gear oil must have dropped out of the diff because it got so hot the pinion was literally sheared off. the differential is definitely shot but I think the driveshaft might be okay. I think the fire may have been gear oil igniting. Luckily someone drove by with a fire extinguisher in their truck so I was able to put it out pretty quickly, hopefully that damage isn't too significant. So I think a full rear end replacement is in order. The mechanic is calling around the local junkyards. I do think it may be worthwhile to repair, if it's around $1000 I could swing it.

 

[Shaggy]

I didn't get a chance to take any pics before they towed it away, but essentially the gear oil must have dropped out of the diff because it got so hot the pinion was literally sheared off. the differential is definitely shot but I think the driveshaft might be okay. I think the fire may have been gear oil igniting. Luckily someone drove by with a fire extinguisher in their truck so I was able to put it out pretty quickly, hopefully that damage isn't too significant. So I think a full rear end replacement is in order. The mechanic is calling around the local junkyards. I do think it may be worthwhile to repair, if it's around $1000 I could swing it.

Definitely get it fixed if it's around the $1000 range. No need the junk it for that price.

 

[duderz7]

If the engine is the same size, so is the gear ratio in the diff when you're looking for a replacement

 

[LibertyTC]

You should call a dealer with your VIN number & ask them if you had a locking 8.25 rear diff or not.
The Trac-Lok does require a Mopar 4 oz bottle of friction modifier added to the gear lube.
I use Lucas dino gear lube and add the friction modifier, as I have a Trac-Lok that is definitely required!
From owners manual:

Mopar SAE 75W-140 (API GL5) Synthetic Gear Lubricant or equivalent.
The 8.25 Corporate Rear Axle should use a SAE 75W-90 Gear Lubricant.
For trailer towing, the lubricant should be replaced with SAE 75W-140
Synthetic Gear Lubricant. Models equipped with Trac-Lok™ require a friction
modifier additive.

 

[Billwill]

My 2002 Export 2.5 CRD Manual has the 4.10 Trac Loc rear diff...label on rear axle states this. I was feeling binding in tight turns on tarmac so replaced the rear diff oil after first pouring in the required Mopar Friction additive. One site...Lost I think...advised to then do a couple of figure 8 turns to settle the rear diff and also advised to use Dyno oil in the Diffs...not synthetic but that always sets off a major argument!

 

[tommudd]

If the engine is the same size, so is the gear ratio in the diff when you're looking for a replacement

Depends, not all are same, depends on automatic or manual as well

 

[tommudd]

My 2002 Export 2.5 CRD Manual has the 4.10 Trac Loc rear diff...label on rear axle states this. I was feeling binding in tight turns on tarmac so replaced the rear diff oil after first pouring in the required Mopar Friction additive. One site...Lost I think...advised to then do a couple of figure 8 turns to settle the rear diff and also advised to use Dyno oil in the Diffs...not synthetic but that always sets off a major argument!

Yep, never ever use that synthetic crap in diffs

 

[duderz7]

Depends, not all are same, depends on automatic or manual as well

Well, I learned something today

 

[slamgranderson]

Okay in case anyone is wondering how this turned out, well the fire actually did more damage than I thought. Wiring harness is burnt, so are the brake lines and the fuel lines. When you turn the key, gas dribbles onto the road lol. So the sad conclusion is that it would be way more than the value of the jeep to repair it. This thing is headed for the scrapyard. A sad day indeed!

 

[LibertyTC]

Sorry to hear that. Hopefully the insurance helps you out.