I was planning to change my Diff oil with 75W 90 Royal Purple but just before doing it I called ARB and they said NO to 75 W90.

They strongly recommend 85W 140...

People with ARB lockers what oil are you guys using. I have ARB diff covers which have a dip stick to check oil but just wondering how much oil do i need to buy.. ARB said 1.8 Litres front D30 and 1.9 Litres D44

 

I was told by the their Dandenong store where most of my JK work has been done. They say arb air lockers take 85w 140 and not to put 75W 90

 

I would say that since ARB strongly recommends 85W 140 that is what I would use. Isn't that the suggested weight if you tow stuff anyway? With all of the extra weight that some of our Jeeps are hauling around it is just like towing.

 

I just put in 2 weeks ago 75W 90 Royal Purple. And have been off road twice with engaging the locker quite a few times. That stuff is kinda pricey. Does royal purple even make 85w140?? And I only put 2Q in the d44 and only 1Q in the d30 and it was coming out the filler hole. I guess the larger gears took up some space in the little d30.

 

I ran across a Toyota board (yeah yeah I know) talking about the same thing and they were all running regular 75W-90 with no issues. I would probably run the 75W-90 since no one within a 100 mile radius of me sells anything heavier.

Isn't there a rep from ARB on the forums?

 

I know that AMSOIL has a 80W-140. I don't have ARB lockers, but did go with their 75W-140. And it is cheaper than Royal Purple.

 

http://www.arb.com.au/resources/pdf/airLockers/6-01.pdf

 

such a heavy oil will struggle to flow back from the outer tubes back into the centre if the holes haven't been enlarged enough.

could result in oil starvation of the diff centre.

I have had this problem!

 

Thanks for asking all these newb questions for me Scott. That way I don't have to take the flac

 

i edited, so here ya go