Went to DCH Jeep in Temecula CA today to get an oil change and front/rear diff service on my 08 Rubi. They wanted (wait for it...) $440 for the whole thing!

It seems that they get $195 per differntial to drain the fluid and top it off. Uh, no thanks. I wasn't in a mood to get dirty or smell like rotten eggs today so I went out to Grease Monkeys in Wildomar CA and got both diffs plus the transfer case services for $160 all in. Still seems high but far more reasonable.

Question though. They said I need Synthetic 75W/140 for the rear and 80W/90 for the front, plus limited slip additive. That's not what I've been reading here. Any comments on that?

 

No LSD friction additive required at all because you have a Rubi with the E locker....this is an open differential until locked electro magnetically...so if they put some in, my recommendation? Drain it out and add clean 75w140...the additive will increase temperature in you diff which you don't want.
By the way, that applies to both your front AND rear diff as they are both equipped with Dana 44's 4.10 gear ratio stock and e lockers.

It looks like they looked up the specs for an X or Sahara with the Trac Lok LSD in the rear and an open diff in the front

 

Not to mention for just about every single synthetic, no limited slip addtive is even necessary. I changed my fluid for $60 (45 for 3 qts AMSOIL 75W-140 and $15 for 2 qts Valvoline Durablend 80W-90) Added 2 Riddler covers for $220 and 15 bucks for 100 grade 8 bolts with lock washers. Total $295 and my differentials are tougher than they were.

 

Never heard that before.

 

Just curious.

75W-90 or 80w-90 is reccommended for standard duty

75W-140 or 80W-140 for heavy duty like trailer pulling.

I don't pull a trailer and everything is mostly stock on my X.

Any advantage with going with the 170 anyway? Or because it is heavier would it just lessen my gas milage without me gaining any real benefit?

I'll about to do my first change out. Either way I'll be using synthetic. So I'm just looking for an opinion on what to use.

 

hmmm...this is what I've been told. It was from a local driveline shop...I think the only reason it came up was because as we all know, temperatures too high are a bad thing and it was just part of the discussion as I just installed an Auburn ECTED which is a clutch pack style LSD/Locker and requires the use of a friction modifying additive...Auburn is also VERY specific with their oils as well, requiring 80w90 NON synthetic....
I'm not an expert on this stuff, though, just trying to share helpful advice....if the temperature comment is false someone could let me know

 

The 75W-140 synthetic for towing, in the rear only. No advantage having it in the front.

 

My advice on this...take it for what it's worth...but if this is a daily driving pavement princess(no offense intended) than the recommended 75w90 is more than adequate, though if your lifted with 35's and tend to punish it a bit offroad, rock crawling and the like where your putting serious torque to wheels, than your safe bet would be 75w140 ...and obviously towing, though your not towing as you stated...just my .02

 

Not a princess:


But not lifted and running 32's. I guess I could go either way then.

Thanks

 

I would agree. (with both statements)