03 rear differential changes or fix

[lonestar]

I hear a very faint drivetrain noise from about 45-65. I probably only hear it because I'm listening for it, since I read about it here. It seems Ford made some attempt to fix all the rear differential problems found on 02's. I found a rear differential assy on EBAY for 07/17/02-07/19/05 Explorer/Mountaineer (2003-2006).

Does anyone know what changed on the rear differential?
Would it mount in a 2002?
Did it really fix anything or would I be better off just rebuilding my own?


I also noticed one of my axle seals was leaking and the fluid was overfilled above the filler plug. It looks like the filler plug is lower than on my 91.

Anyone have experinece replacing seals on their own? Bearings?
Is there a fix to the noisy rear diff?

 

[ExplorerDMB]

If you go into the Technician Corner the TSB on this issue is there. They recommended a rebuild kit

-Drew

 

[lonestar]

I found this awhile back.

TSB 05-12-6

It seems many are experiencing noise again after the TSB repair work has been performed.

I was wondering if anyone has performed this work on thier own. But more importantly, is there a real fix to this problem?

 

[bos20k]

I'm going to be bringing mine to the dealer to have the diff service done under warranty next week. Exact problem that is in that TSB. The mechanic said there is a newer TSB than that one but basicly the same thing. I asked him (actual mechanic, not service advisor or whatever) if they have many of these come back for the same problem after the repair has been done and he said no. They had one come back because it wasn't shimmed right when they did it but other than that no. He said it is a common problem and they do a lot of them.

My dealership has a good service department though so your milage may vary...

 

[lonestar]

any clue what they did?

how did it turn out?

 

[bos20k]

They replaced the 'ring and pinion'. The same differential service that is in that TSB. Seems to be ok so far... Took them like three days to get it done. First day the guy that was going to do it was tied up on another car. Second day he had it all apart and didn't have it done yet and the service advisor wasn't going to push him to get it done since they wanted to make sure it was done right. Picked it up the third day.

 

[lonestar]

Thats it? Just replaced the failing parts.

Any changes in alignment, shims or backlash? Or just back to original specs which may fail again.

Is there any known solution?

 

[bos20k]

Well, to my knowledge whenever you replace the gears in a differential it must be re-shimmed and adjusted for the new gears that are going in. You can not just leave it adjusted/shimmed the way it was for the old gears or it is almost guaranteed to fail. That goes for any differential not just Explorer diffs. I'm not a mechanic but that's what I've read about a thousand times.

I also forgot to mention that they changed the diff oil to 75w140 I think it is (as opposed to 75w90 from the factory) as specified in the TSB. Makes me wonder if this problem would have happened at all had they come with 75w140 from the factory...

 

[lonestar]

True, you would need to adjust for new gears. I was just wondreing if they went by differenct specs.

 

[bos20k]

I would assume not anything really different, just the new gears and the heavier diff oil when they did the repair. Explorers have an 8.8" rear end which is in a bunch of other ford products including my CrownVic. I doubt that there is anything inherently wrong with the design in the Explorers that causes this. My guess would be that it was low quality gears from Visteon or wherever combined with diff oil that is too thin. That's just a guess based on what I've read and the fact that they replace the diff oil with heavier stuff.

As far as having the repair done and having the problem come back I would guess that is due to poor quality work being performed at dealerships. Maybe they aren't taking the time to shim and adjust the new gears properly?

That's all just somewhat educated guesses on my part though so take them with a grain of salt.