Busted diff

[PaulThePhotographer]

Sean K. previously said:

If you do blow it so bad, you can't move it, take out the rear driveshaft and run it back to pavement in front wheel drive (assuming the trail isn't so bad that you have to have 4WD to get out).Sean

uphill previously said:

I've done this before (not with the FJ) and it works just fine. Disconnect the drive shaft, throw it in the back or on the roof and drive home. As Sean said, the only problem comes if you're in the back of nowhere. That's why it pays to go with at least one other rig.

I guess I don't understand this "remove the DriveShaft thing. If the rear wheels are still turning isn't the ring and pinion still turning also? Even with the driveshaft out?

And if the Ring and Pinion are still turning then they are still crunching the teeth or locking up on parts of the teeth.

????

[Sean K.]

FJCRUSR previously said:

You can't drive an FJC for long or fast on a broken rear diff. even without the drive shaft...
That's unless you live very close to the trail.
You do the best you can to get on pavement and hope for the best.

Largely depends on what is going on with the diff itself. If it's sheared most of the teeth, it may just clunk really bad and only bind occassionally as it rotates. If it completely siezes up, you'll have to pull both axle shafts, pull the third (after getting the DS off) and then put the axle shafts back in.....then it will free roll.

Man, a floater would be a lot easier in that worst case scenario. ***EDIT*** At least it's not a fawkin' C-clip axle.

Sean

[Sean K.]

PaulThePhotographer previously said:

I guess I don't understand this "remove the DriveShaft thing. If the rear wheels are still turning isn't the ring and pinion still turning also? Even with the driveshaft out?

And if the Ring and Pinion are still turning then they are still crunching the teeth or locking up on parts of the teeth.

????

Yes, but you're not transferring any of that impact load to your tcase. If the ring and pinion bind and won't allow the wheels to turn and the tcase continues to put power down the driveshaft....you could damage the shaft and the tcase.

See my post above this one for further info.

Sean

[FJCRUSR]

PaulThePhotographer previously said:

I guess I don't understand this "remove the DriveShaft thing. If the rear wheels are still turning isn't the ring and pinion still turning also? Even with the driveshaft out?

And if the Ring and Pinion are still turning then they are still crunching the teeth or locking up on parts of the teeth.

????

BINGO!

[Sean K.]

Not bingo....re-read.

Sean

[TrAiLbUs1]

Sean K. previously said:

Depends on how bad it's busted. If you only lose a few teeth....you can usually drive out unless the trail is REALLY bad...in which case, the ring and pinion will be significantly weaker due to the missing teeth and will likely start to shear teeth that are next to the broken ones. It will likely get progressively worse as you continue loading the gears....so easy does it until you can get back to pavement (assuming the initial failure isn't catastophic).

If you do blow it so bad, you can't move it, take out the rear driveshaft and run it back to pavement in front wheel drive (assuming the trail isn't so bad that you have to have 4WD to get out). If front 2WD doesn't cut it.....you may have to leave it, get a built third and come back to it if another vehicle can't help you make it out without the rear having power.

HTH,
Sean

I was going to say the same thing thank you!!

[FJCRUSR]

Sean K. previously said:

Largely depends on what is going on with the diff itself. If it's sheared most of the teeth, it may just clunk really bad and only bind occassionally as it rotates. If it completely siezes up, you'll have to pull both axle shafts, pull the third (after getting the DS off) and then put the axle shafts back in.....then it will free roll.

Man, a floater would be a lot easier in that worst case scenario. ***EDIT*** At least it's not a fawkin' C-clip axle.

Sean

I just happened to be right next to 3 FJC that busted rear diff. including Milkyxj...he was pulled to the road for the wrecker.
The other two, we took the gear out as you mention in the Home Depot parking lot.

[PaulThePhotographer]

I understand not trying damage anything else like a transfer case or transfer gears but if the Ring and Pinion is trashed I just wonder much it is going to roll even with the DS out?

We just had this happen to one of our group also. After it went out it did not roll but maybe 50 feet. Then the wheels locked up. Then it would unlock for a bit when we put it on the trailer (deep in the woods, Thanks AGAIN Jerry) but he was able to put in in reverse and drive off the trailer at the dealership. Clunking and Chunking with ever revolution.

But I guess there is no good option at a time like that. If you have to drop the DS and drag the frozen rear wheels, it just something you have to do?

[Sean K.]

I'm really tired tonight so I apologize in advance if it seemed like I was being short with you....I'm just trying to be brief as I'm exhausted.

Mainly, my point is that you have to attack a break like that (which IMO is pretty significant as it's not something you can fix on the trail easily like a broken axle shaft)....you have to take it in stages. When plan A doesn't work....i.e., just try and limp it off the trail, you move to plan B (taking out the rear DS and seeing if you can make it go then). If that doesn't work....plan C is next (take out both shafts, the 3rd member, and reinstall the shafts). You lose nothing by trying one at a time until you find a solution that may work. It's not like you're putting anything back on in plans A or B that you'll have to remove to get to plan C.

Hope that explains it.

Sean

[PaulThePhotographer]

FJCRUSR previously said:

I just happened to be right next to 3 FJC that busted rear diff. including Milkyxj...I pulled him to the road for the wrecker.
The other two, we took the gear out as you mention in the Home Depot parking lot.

I saw that thread.... What a story!