Need some Differential oil guidance

[silver 07 ready for mud]

I was reading through the old posts on differential oils, and saw a lot of different opinions so still looking for a little advice, I have an 07 4wd automatic with 150,000km (93,000miles), I don't normally pull a trailer but often have the jeep pretty loaded up, and been doing a lot of driving up and down hills not sure if that makes any difference. I bought some quaker state full synthetic 75W-140 GL-5, looks like it already has the additives in it. So just wondering if I can use this in both the front and the rear or if I should be looking at something else altogether.

 

[eyehatetofu]

I think in the Owner's Manual it states to use 75W-90 in the front diff. That being said, I ran 85W-140 synth blend stuff for 30K miles (2 fluid changes) in the front with no issues. I run 75W-90 front and rear now, but that is because I'm a tool and don't wheel anymore.

 

[silver 07 ready for mud]

I haven't gotten mine out too much yet only had it for about 10,000 miles, been slowly catching up on what seems to be a total lack of maintenance from the previous owner, from the look i'm not sure if the diffs have ever had the oil changed, i noticed it still had the original spark plugs when i swapped them out. just want to make sure i'm not going to do anything damaging as i work on it. Also was looking at what is the best way to drain the oil heard both siphoning out and opening the case as preferred options, and finally anything i should do before changing it like take it out for a long drive to get things warmed up?

 

[eyehatetofu]

There is only one way to change the front, and definitely take the cover off of the rear. Trying to siphon it out would be a pain in the ass. Plus you wouldn't be able to check the little magnet in the bottom of the housing for metal shavings and what not.

Just a tip, buy a pump to pump the gear oil into the diffs. Trying to do it without the pump was not fun.

 

[Neb1373]

What is the call for the differential oil changes? I was going to do mine tomorrow at 90k miles but aldata states to do it around 120k miles I believe. It actually states that it is not necessary. I got the jeep 10k ago and haven't done any 4 wheelin :-( and very little pulling with it. I don't know the previous records so I will do the smart thing and assume that it had not been done. Should I do it now? Wait till next spring? Wait till the 120k?

 

[ridenby]

Oil/grease is cheaper than parts. If in doubt;change it out.

 

[tjkj2002]

What is the call for the differential oil changes? I was going to do mine tomorrow at 90k miles but aldata states to do it around 120k miles I believe. It actually states that it is not necessary. I got the jeep 10k ago and haven't done any 4 wheelin :-( and very little pulling with it. I don't know the previous records so I will do the smart thing and assume that it had not been done. Should I do it now? Wait till next spring? Wait till the 120k?

Diff fluid is every 12,000-15,000 miles for both front and rear diffs if using synthetic gear oil.

 

[TwoBobsKJ]

Go with standard dino oil (such as Coastal, Lucas or other equivalent standard gear oil.)

Use 80w-90 for normal driving, 85w-140 for towing/off-road in both front and rear diffs.

Here's a link to another discussion on here about synthetic vs. standard dino oil. For my money there's no use spending the extra for synthetic - and yes, changing the diffs every 12-15,000 miles is a good idea. It's an easy job (with the oil pump as mentioned above - cheap at your local auto parts store) and will keep things humming... :emotions33:

Bob

 

[silver 07 ready for mud]

ok thanks for all the info I think i'll be taking back the synthetic and getting some dino this week, it was $70 for the synthetic here and less than half for the standard, with that savings i can upgrade to synthetic motor oil for my next change