in the process of changing the diff fluid. the write up on project-jk.com says the front diff needs 1.35 quarts. and fill til the oil starts leaking from fill hole. I followed the write up and think i did everything ok but when i went to fill it back up i used just under 1 qt. i am pretty sure that i let it all drain out. should i just say "its done and forget the quantity" did i fill it too fast and not let it settle? Help please. It is the D30 in the front if that makes any difference

 

You are fine. I use the entire quart bottle when I fill mine, just place your finger halfway over the hole and the tip of the bottle above and use the entire bottle. I have not had any overflow issues with this.

 

great thanks, i was afraid that i was not using enough. how about the back D44? how much do you end up using there?

 

I don't remember the amount, but I do the same thing, fill it until it runs out, usually putting as much in with finger over hole as possible.

 

My front was the same way with the stock cover. When I took out the fill plug oil started coming out and it took less than one quart to fill it back up. I figured since it was coming out it should be good. The rear was the same way and took about 2 quarts to fill. I have since replaced the stock covers with Riddles. They will hold more oil and have a higher fill hole. I now have 1 quart in the front D30 and 2.38 in the back D44. I believe as long as the level is close to the axle center you are good.

 

I need to change my diff fluid also. Is there a specific kind, weight, brand I should use??? This is the first time I have had to do this so I am not sure what to buy.

Thanks
Matt

 

First, what axels do you have, specifically do you have a limited slip differential in the rear?

The recommended weight for the front is 75w90. You can use 75w90 or 75w140 in the rear. If the rear has limited slip you need a lube with a friction additive.

I use the heavier weight in the rear for towing purposes and heavier use.

Your first choice should be if you want to use a regular dino or a synthetic. I personally use synthetic because I believe it will not break down as fast under the high temperatures/conditions in the diffs.

I use Mobil 1 synthetic as it has the additive for the LSD.

There are many options, I would recommend searching the site and reading the many threads.

Good luck choosing!

 

75w-90 in the front and rear or if you have the tow package it's 75w-90 front and 75w-140 in rear. Use a good name brand synthetic and you want have to worry about adding a friction additive. I used Mobil 1 but there are several others that are just as good (royal purple or amsoil). If you can change you're engine oil you can change you're diff. oil. Those threaded plugs can sometimes be a pain to break loose. Just make sure you take the fill plug out before you take the drain plug, that way you want be stuck with a empty differential if you can't break it loose. WOL did a good write up that should help.
https://www.jk-forum.com/showthread.p...rential+change

 

I like the Mobil 1. I also wrap the threads of the drain plug with teflon tape to make them seal, and the drain plug will come loose easier the next oil change.

 

https://www.jk-forum.com/forums/show...l+fluid+towing


Great information here too:

https://www.jk-forum.com/forums/sear...archid=4617043


Found this today during a search. It's time for my 1st diff change.

Found a small transmisson oil leak at the cooler line while I was under there that was leaking onto the track bar and front diff... That fluid is flammable as all hell...I better get on it.

This site has a lot of very helpful info! Thanks to all that contribute.