Seeking opinions on damaged differential

Noreaster1967

Noreaster1967

TJ Enthusiast
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Joined
Dec 13, 2019
Messages
119
Location
New Gloucester, ME
I was recently told that the differential in my '01 Sahara is toast and needs replacing. I expected that, given the way it was driving. I was also told that the damage was such that it will require me to replace the entire housing as well because of scoring. I have doubts about that, but know very little about gears and differentials, so I took some pictures to see what people here think. I will try to get better angles if there is anything in particular I should be looking at.
Thanks in advance.

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There might be some confusion on the wording. A housing usually means the whole axle housing, like the cast iron part in the middle with the tubes attached to it. Rarely does that need to be replaced.

The part that the ring gear bolts to and contains the spider gears can be called the differential case. I could see that maybe needing to be changed in your situation because the spider gears are pretty tore up.

Who told you you needed a housing? Is it someone you trust? I without disassembling it I would assume just the spider gears are damaged.
 
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The spider gears look trashed, and maybe they've scored where they ride in the carrier so you need a new carrier but I don't see anything in there that leads me to believe you need a new housing (I usually use that term to refer to the entire axle housing - everything between the brake backing plates). Maybe they're referring to the carrier as the housing?
 
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freedom_in_4low said:
The spider gears look trashed, and maybe they've scored where they ride in the carrier so you need a new carrier but I don't see anything in there that leads me to believe you need a new housing (I usually use that term to refer to the entire axle housing - everything between the brake backing plates). Maybe they're referring to the carrier as the housing?
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I asked him that and he assured me it was the axle housing. I Know he didn't remove anything but the cover, so he couldn't have seen more than what's in the photo. I'm currently looking for someone else in my area that has experience in this department for a second opinion, but figured someone here might see something I don't.
 
Paul Ruggles said:
There might be some confusion on the wording. A housing usually means the whole axle housing, like the cast iron part in the middle with the tubes attached to it. Rarely does that need to be replaced.

The part that the ring gear bolts to and contains the spider gears can be called the differential case. I could see that maybe needing to be changed in your situation because the spider gears are pretty tore up.

Who told you you needed a housing? Is it someone you trust? I without disassembling it I would assume just the spider gears are damaged.
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It was the mechanic at one of the only off-road shops in my area. I can't say I trust him any more than the next guy, but I don't really know him.
 
Noreaster1967 said:
I asked him that and he assured me it was the axle housing. I Know he didn't remove anything but the cover, so he couldn't have seen more than what's in the photo. I'm currently looking for someone else in my area that has experience in this department for a second opinion, but figured someone here might see something I don't.
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Definitely get that second opinion. Don't need to limit yourself to offroad shops, either. There are a couple of shops around here that specifically deal with differentials.
 
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freedom_in_4low said:
Definitely get that second opinion. Don't need to limit yourself to offroad shops, either. There are a couple of shops around here that specifically deal with differentials.
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I definitely get what you're saying. I only went to the off-road shop because my old mechanic doesn't have experience with lifted vehicles and missed the differential issues when I first brought it in to be looked at. Now that I know what's wrong, I can look for a gear shop.
 
From the photos it just looks like some damaged/worn spider gears... Without pulling the main caps to check for damage under the bearings or for damage around the pinion, I wouldn't think the housing trashed. I 2nd finding a diff specialty shop. Does the offload shop do a lot of regearing for the area? did someone recommend you to them?
 
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At worst you need a new carrier. I seriously doubt you damaged the housing at all. No way to really tell until you pull the shaft and carrier out. Find a gear shop, get a quote or two to overhaul with new carrier.
 
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Axeman said:
From the photos it just looks like some damaged/worn spider gears... Without pulling the main caps to check for damage under the bearings or for damage around the pinion, I wouldn't think the housing trashed. I 2nd finding a diff specialty shop. Does the offload shop do a lot of regearing for the area? did someone recommend you to them?
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There’s very limited wheeling options in my state, so most of the lifts and mods are backyard projects. The shop I went to is the only one I know of in my area, but I don’t personally know anyone that has used them.
I do know of a few good shops that specialize in transmissions and rear ends, so I’ll get ahold of one of them.
 
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Is this guy able to set up gears? If not, it is easier to swap the entire axle.
 
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Noreaster1967 said:
Thanks for all the input, guys. Do you think the damage could have been the result of putting larger (31") tires? Incorrect pinion angle?
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Doesn't look like that to me. Did you find any metal in the diff or did this happen before you bought it? Putting 31 or heck even 37 inch tires should't cause damage like this.

a bad pinion angle would kill your u-joints, but not the spider gears.

One thing to consider is maybe moving up to a lunchbox locker (super easy to do yourself (seriously) and cheap) or a full case locker (not easy and not cheap but might be almost as cheap as getting new gears and having them set up.

My son and I installed a lunchbox locker in the front of my TJ in a few hours which counts the time of taking a break and eating lunch. Lot's of Youtube videos on the subject. Plus it will give you more familiarity with your Jeep, how it works, and a REALLY BIG sense of pride for taking things into your own hands!

Just my .02 cents worth.
 
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HYRYSC said:
Doesn't look like that to me. Did you find any metal in the diff or did this happen before you bought it? Putting 31 or heck even 37 inch tires should't cause damage like this.

a bad pinion angle would kill your u-joints, but not the spider gears.

One thing to consider is maybe moving up to a lunchbox locker (super easy to do yourself (seriously) and cheap) or a full case locker (not easy and not cheap).

Just my .02 cents worth.
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It was like that when I bought it. Every once in a while I'd feel a pop when turning at lower speeds. As for metal, yes, I found pieces gear when I opened it up.
 
hmmm, well then it might, not necessarily, but it might have contaminated the bearings on the diff. You might want to get a mechanics stethoscope and put it in the air and turn R&P slowly to listen for any grinding noises in the carrier bearings. If not, I would still flush everything out really well and probably even replace the diff fluid after a couple hundred miles at the most just to make certain.

Is this your daily?
 
Looking at your pictures, all I see is a couple of spider gears that are bad. If he is saying you need a new housing or even a new carrier without even pulling out the carrier to investigate, take it to somebody else and don't go back to him.

From the looks of it, it's a simple spider gear replacement need from the pictures you posted, nothing more. The metal pieces you found are most likely those bits of the spider gears.

As far as the other issues you have such as a pop when you turn, investigate those separately from this.
 
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