Diff Oil

[Atrus]

Well, I am almost at 21k, which means I am significantly over the recommended 15k change for the diffs.

I have two questions:

1) Will the 75W-140 really make any difference for me? It's twice as expensive. I don't tow much, and if I do, it's very light (<1,000 lbs). I do offroad about half a dozen times a year, but it's nothing that insane.

2) My manual calls for 80W-90 in the front and 75W90 or 75W140 in the rear. I'd imagine 75W90 in the front would be just fine, wouldn't it? Reason being Mobil1 (at least at the store I went to) isn't offered in an 80W90. I could run Valvoline synthetic blend in that viscosity. I'd rather just get all the same if it won't make a difference.

 

[tjkj2002]

You'll be fine running Mobil1 75w-90 in both diffs.

 

[Atrus]

Good deal, that is what I hoped to hear. Thanks!

 

[ShafferNY]

I had this very same question. I'm in the process of changing the differential fluids in my Jeep. It cost me $70 for four quarts of 75w-140 and two quarts of ATF+4.

I have a 14' aluminum boat that I tow and that's it. I thought I'd spring for the expensive stuff just for the added insurance. Not only that, if I do tow anything heavier in the future I'm good to go.

 

[Dave]

Just as a side note, I got Valvoline synthetic 75-140 at wally mart and it was around $10 a quart and Mopar ATF+4 there also for around $4.85 or so. (I tow)

Atrus, I thought the diff's needed to be changed at 30,000 miles? Maybe I was looking at the wrong schedule?

Also, do yourself a favor and go and get a lower unit gear lube pump for a boat outdrive. It will fit on any quart bottle and you can pump it in the diffs at any angle. I have used one for years for boats and diff's. When you see one you will know what I mean. They are only around $10. Makes life easier.

Dave

 

[Atrus]

Thanks Dave - I'll check out Walmart tonight as it's where I buy my engine oil (Mobil 1).

The Mobil1 75W90 was about $9 a quart and 75W140 was $6 a quart at the parts store.

I definitely plan on going with the pump!

So, stupid question time, but let's say 75W140 is cheap enough at Wally World that I use it....is it OK to run that in the front axle as well? Manual doesn't show it for the front even for heavy towing.

 

[jeepkj02]

So, stupid question time, but let's say 75W140 is cheap enough at Wally World that I use it....is it OK to run that in the front axle as well? Manual doesn't show it for the front even for heavy towing.

75w140 should be fine in both diffs.

 

[tjkj2002]

Atrus, I thought the diff's needed to be changed at 30,000 miles? Maybe I was looking at the wrong schedule?

Diffs need new fluid every 12,000 miles according to schedule "B".

So, stupid question time, but let's say 75W140 is cheap enough at Wally World that I use it....is it OK to run that in the front axle as well? Manual doesn't show it for the front even for heavy towing.

You will be just fine,I ran 75w-140 in both diffs since new.