5.13 Gears Installed ? regarding gear oil [Archive] - JKowners.com : Jeep Wrangler JK Forum

: 5.13 Gears Installed ? regarding gear oil

09-09-2007, 08:39 AM
Hello All,
I need some advise. I just had 5.13 gears installed in my Unlimited Jk. I was told that I should change out the gear oil after 500 miles. I want to put Mobil 1 Synthetic oil 75w-140. The question is the manual does not recommend this for the front differential only the rear if you are going to be towing. I want to put it into both. Does anyone see a problem with doing this. Second question is how much fluid should I be able to put back into both the front and rear differentials. I was only able to get just over 1 quart into the front and just shy of 2 quarts into the rear. Does this sound normal.


09-29-2007, 12:08 PM
The manual wants 80W-90 (API-GL5) or equiv. or 75/140 for towing. So you should be good there.

The amount of fluid will depend on what axle & covers you have on them.

I have D44s with Riddler covers.

You want the fill level to be just up to the bottom of the axle tube seal. This can translate into about 2" below the bottom of the fill hole. Use a bent straw or similar hi-tech device.

On my setup, the front used about 1.5Q and the rear 1.75Q


10-02-2007, 03:51 PM
Thanks for the reply. :) That synthetic oil is expensive. Now I just wish I had installed my Crane cover before I changed it. Oh well just something else to do with my money.