That Jato uses a sealed gear differential which is intended to be used with shock oil. Regular diff oil of 1000wt+ is far too thick for the application of a RWD 1/10 ST, which is why its intended to be used with shock oil. The stock weight of shock oil is 30wt, of which it is filled with from the factory. Now after I rebuilt mine for the first time I did notice that there wasn't much in there, but it did have shock oil in it which I assumed to be the 30wt Traxxas claimed, I have no reason to dispute this.

If your wanting a more positive feel with less diff action then simply go for a heavier weight, a 40wt or 50wt would be a good starting point if this is what you desire.

dam -is anyone ever gonna post their manual or something from traxxas to end this dispute? solid info just so someone cant come back and say again-its grease-no its shock oil-no its diff oil????

Wow! I just got a jato last week and can't believe all the stuff I am reading on it, mostly from people that don't own one. Anyway, if and when I have questions that the manual doesn't cover I would REALLY recommend the traxxas support line or website. After all, if you just paid over 350.00 hard earned smackers on just the truck alone, why listen to advice from some anonymos(spl?) kid on the net that can't wait to ruin your stuff? Support team is there for a reason, I say!

found the manual online-
Sealed Limited Slip Differential
The sealed limited slip gear differential can be precisely tuned with lighter or heavier lube for maximizing rear traction and cornering performance. Superior silicone-seals are used for reliable sealing. Unlike a ball differential, Jato’s sealed-gear differential never slips or wanders out of adjustment, and it is virtually maintenance-free. It’s definitely the best solution for the demands of a high-performance truck like Jato. You get all the benefits of an adjustable limited slip differential without all the maintenance hassle of a ball diff. Jato’s transmission design provides easy access to the differential. Just remove four screws and the rear cover and there it is. Trackside tuning is fast and easy.
Sealed, limited-slip gear differential is fully tunable with standard silicone shock oils. Ball differentials simply can’t compete for tunability, efficiency and reliability.

I have no idea what your problem is, but you are the only one that is incorrect in the entire thread, everyone else had some kind of valid, factual point and wasnt trying to force something on someone.

And I'm really not offended by you, I just think you're the immature one, this dude was kind of trying to make you look like an alright guy. But obviously you arent. And it seems that you are the one ASSUMING you have a clue as to what you are talking about, but again OBVIOUSLY NOT.

Heres a few pics I took of my jato manual, that I should have looked in in the first place, but I got a little more info here than I would have the manual.

So to all of those who pointed me in the right direction, thanks again.