Changed Diff Fluids......

And is the 75W140 the recommended weight or are you planning on doing a bit of towing (or other reason)? IIRC isn't 80W90 the normal fluid for non-Rubis? JELo

75-140 Synth is what the axel tag calls for. I'm not sure what non-Rubis call for. The axel tag is on the drivers side of the front pumpkin and the passengers side of the rear pumpkin.

You could go look.

It has a limited slip rear end with air lockers front and rear.

PC

Ah, now that makes sinse! Hm, cool! Nick

Don't have a Rubi handy but I did check my '02TJ Sport (w/D44 TrakLoc rear) and no special markings underneath other than for the friction modifier in the rear. I guess it must be because of those special lockers you have. I was thinking that when I go to change the diff lube on mine that I would switch to full synth but wasn't sure whether to go with 80W90, 75W140 weight. The owners manual recommends 80W90 for normal use and specifically 'synthetic' 75W140 for towing and harsh conditions. As cold as it get out here during the winters, I didn't want to go with anything thicker than what is actually necessary. I suppose dino 80W90 and synth 75W140 might give about the same performance in the extreme cold.? JELo

Didn't want you to check a Rubi.......I have one and that's what it calls for";^) I would recommend that you use 75W140 if you do any off roading at all. Off road work is considered by Jeep as "harsh" conditions. Actually anything other than sunny weather and 72F at 35mph is considered "harsh." LOL! Don't think that the cold will affect as the lower number is actually lower than the 80W90. So when cold, it should have lower viscosity than the standard stuff.

PC

Why would you do that?

Imho, it is a waste of time and money to do the transfer case. It doesn't produce nearly as much break-in scrap as a ring and pinion. It's your money though...

Earle

IIRC the Rubicon's rear limited slip is a gear-driven unit, not a clutch-pack type unit, so a friction modifier shouldn't be necessary.

• * * Matt Macchiarolo
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I thought the Rubicon (based on the marketing stuff I have heard) had full lockers front and rear? Not limited slip in any way, clutch-pack nor gear-driven. Not true?

Dave

I believe they are locking limited slips. Basically, the new Trac Tech electracs (a locking version of the tru-trac, IMHO, the best limited slip unit made). Of course, I could be wrong... just ask my wife... ;)

The front is a selectable locker, the rear is a limited slip with a selectable locker. The limited slip is a True Trac type LS, using helical gears rather than clutch packs. But the lockers aren't really electric, they are switched with air pressure...the air compressors for the lockers are located just behind the transfer case, a poor choice of location if you ask me...

• * * Matt Macchiarolo
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They are electric lockers or air lockers, the driver turns them on and off. When off (the normal condition for street use), the diff is a limited slip in the back, and open in the front.