Differential Oil

07streetbobrider

New member
I was at the dealer today for another free oil change and inspection. On the inspection they told me I need rear brake pads and rotors turned ($329.95) and they said the rear diff oil was dirty. Quoted me $149.95 to change the rear diff oil! They wanted to make an appointment- no thanks I'll do it myself (and save receipts). Jeep has 30,000 miles on it and the rear oil was changed about 10,000 miles ago with some warranty work. My question is can you tell if diff oil is dirty by looking at it?
 
I was at the dealer today for another free oil change and inspection. On the inspection they told me I need rear brake pads and rotors turned ($329.95) and they said the rear diff oil was dirty. Quoted me $149.95 to change the rear diff oil! They wanted to make an appointment- no thanks I'll do it myself (and save receipts). Jeep has 30,000 miles on it and the rear oil was changed about 10,000 miles ago with some warranty work. My question is can you tell if diff oil is dirty by looking at it?

After 30 of normal driving, it likely needs changed. Its easy to do yourself and you can savr a ton of money. There is a write up on here about how to do it.

Edit: i completely missed the part about the oil being changed 10k ago...
 
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I was at the dealer today for another free oil change and inspection. On the inspection they told me I need rear brake pads and rotors turned ($329.95) and they said the rear diff oil was dirty. Quoted me $149.95 to change the rear diff oil! They wanted to make an appointment- no thanks I'll do it myself (and save receipts). Jeep has 30,000 miles on it and the rear oil was changed about 10,000 miles ago with some warranty work. My question is can you tell if diff oil is dirty by looking at it?

Being that you only have 10k on the oil I would say your ok. Per the manual you should change it every 30k of normal driving or every 15k under heavy conditions (towing, off roading, etc). If you have wheeled it and went thru any water crossings then you should do it after each one to make sure no water is in there.
 
I used Mobil 1 Synthetic Lubricant LS on my last Jeep which was a Sport with a limited slip rear dif. Is there a particular oil that needs to be used for the Rubicon with e-lockers? I need to change mine today and not sure if I should stay with Mobil 1 or go a different brand.
 
My question is can you tell if diff oil is dirty by looking at it?

I guess you'd have to define what "dirty" is. You can definitely tell if you have water in the diff but short of draining the diff, it can be hard to tell what the real condition of the gear oil is just by opening up the fill bolt. Depending on how hard you use your Jeep, a change at 15,000 is something you might want to do.
 
I used Mobil 1 Synthetic Lubricant LS on my last Jeep which was a Sport with a limited slip rear dif. Is there a particular oil that needs to be used for the Rubicon with e-lockers? I need to change mine today and not sure if I should stay with Mobil 1 or go a different brand.

U don't need an additive for the elocker. If it has it in the oil already like rp, and some others it's fine. I use Lucas 75-140 in the rear I get from Amazon in a gallon. Has worked great for along time for me.
 
I was at the dealer today for another free oil change and inspection. On the inspection they told me I need rear brake pads and rotors turned ($329.95) and they said the rear diff oil was dirty. Quoted me $149.95 to change the rear diff oil! They wanted to make an appointment- no thanks I'll do it myself (and save receipts). Jeep has 30,000 miles on it and the rear oil was changed about 10,000 miles ago with some warranty work. My question is can you tell if diff oil is dirty by looking at it?

others have addressed the gear oil, the brakes are also easy to DIY and for a lot less. You can get both rotors turned for cheap, Pep boys used to do it for around $15 /rotor or buy replacement rotors about $50/rotor, new pads $60 and save by doing it yourself.

if you buy new rotors get the others turned, wrap them in oil paper to keep them from rusting and put them away for the next time.
 
I was at the dealer today for another free oil change and inspection. On the inspection they told me I need rear brake pads and rotors turned ($329.95) and they said the rear diff oil was dirty. Quoted me $149.95 to change the rear diff oil! They wanted to make an appointment- no thanks I'll do it myself (and save receipts). Jeep has 30,000 miles on it and the rear oil was changed about 10,000 miles ago with some warranty work. My question is can you tell if diff oil is dirty by looking at it?


I'm betting that they looked at the mileage of the jeep (30K) and based on that said you need the diff oil changed. Not looking at the service record that would show it was changed at 20K. That said, $150 for something that takes longer to explain how to do it rather than doing it is crazy. WAL has an excellent write-up (as usual) on diff oil change. I'm at the point that I look up his maintenance write-ups before bothering looking in one of my hardback manuals.


Diff:
http://wayalife.com/showthread.php?...K-Wrangler-Differential-Fluid-Change-Write-Up

Brakes:
http://wayalife.com/showthread.php?4349-MAINTENANCE-Jeep-JK-Wrangler-Rear-Brake-Pad-Replacement
 
I am going to do it myself. I was wondering if they could just look at it and see if it's dirty. They said the front diff is good. Just checking the integrity of this dealer in Modesto. Had some bad experiences with a ford dealer a long time ago. Blows me away if I would have said yeah fix it I would be out around $500. Thanks.
 
I am going to do it myself. I was wondering if they could just look at it and see if it's dirty. They said the front diff is good. Just checking the integrity of this dealer in Modesto. Had some bad experiences with a ford dealer a long time ago. Blows me away if I would have said yeah fix it I would be out around $500. Thanks.

Your front diff will always look "cleaner" as for the most part, it isn't under a load. Your rear is always doing work and so yeah, it'll look "dirtier" especially if you are running a higher gear ratio. That being said, draining the oil and looking at the drain plug to see how much metal filings are on it is really the only way to know for sure just how "dirty" it really was. Again, if you're running a higher gear ratio and do a lot of hard driving, it isn't such a bad thing to change your fluid once every 15k.
 
I am going to do it myself. I was wondering if they could just look at it and see if it's dirty. They said the front diff is good. Just checking the integrity of this dealer in Modesto. Had some bad experiences with a ford dealer a long time ago. Blows me away if I would have said yeah fix it I would be out around $500. Thanks.

Drive it around for 5-10 miles, then pull the fill plug and put a long zip tie down in there. That will at least give you a rough idea of fluid condition and if there is any metal, water, etc. But as others have said, it may be time for a service just for PM anyway. Fluid should be a amber-yellow color, fyi. Dirty fluid will be black or dark brown. If it has water in it, it will be muddy looking and won't really look like oil.
 
Your front diff will always look "cleaner" as for the most part, it isn't under a load. Your rear is always doing work and so yeah, it'll look "dirtier" especially if you are running a higher gear ratio. That being said, draining the oil and looking at the drain plug to see how much metal filings are on it is really the only way to know for sure just how "dirty" it really was. Again, if you're running a higher gear ratio and do a lot of hard driving, it isn't such a bad thing to change your fluid once every 15k.

Sometimes I'll change my rear twice before the front, and when I do Change the front, it still looks new.
 
I was surprised how hot the rear diff can be and how "dirty" the oil can get especially after towing a U-Haul in the AZ desert.:eek: Like voting, do it "early and often". It's cheap insurance.:yup: The dealers and lube shops make a fortune on this type of work.:mad: Good luck.
 
Well I took everyone's advise to change the diff oil. I decided to just change it out this time and open it up next time. Pulled the plug and it has 4-5 chunks of metal stuck to it. Great. Pulled the cover to see where it came from. Chips came from the spider gears. What would cause that? Anyway I bought the jeep with the optional tracloc limited slip rear end. It looks like it is an open diff to me. Is this what jeeps limited slip looks like? With both wheels off the ground when you spin one the other doesn't move.View attachment 173844Diff.jpg
 
Well I took everyone's advise to change the diff oil. I decided to just change it out this time and open it up next time. Pulled the plug and it has 4-5 chunks of metal stuck to it. Great. Pulled the cover to see where it came from. Chips came from the spider gears. What would cause that? Anyway I bought the jeep with the optional tracloc limited slip rear end. It looks like it is an open diff to me. Is this what jeeps limited slip looks like? With both wheels off the ground when you spin one the other doesn't move.View attachment 173844View attachment 173845

It's not super un-common for those things to chip on Jeeps. You'll have to replace them eventually, but I've seen guys let it go and just keep driving it. I'm sure others here will have experience of chipped spider gears and how long they drove on them after finding out they were chipped. Sure looks like an open diff to me, but you can't always test limited slip systems on a lift. A lot of time, there has to be a low traction condition for them to engage. If you have it, you should have some clutch packs between the side gears and the carrier. May be hard to see though. If you have your diff tag, a dealer will know for sure. Do you see any springs around the side gears?
 
No but I didn't look too hard in that area. It did extremely well in 2 wheel drive yesterday in the snow so it seemed like it had a limited slip. Still under warranty but I hope they don't give me crap about not being stock.
 
No but I didn't look too hard in that area. It did extremely well in 2 wheel drive yesterday in the snow so it seemed like it had a limited slip. Still under warranty but I hope they don't give me crap about not being stock.

You can enter the vin on jeeps website to get a buildsheet, thatll take guesswork out of your factory options
 
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