synthetic gear oil?

[whiterubicon]

I think that I am going to change to synthetic oil for my rubi's engine. After making that decision I began to think about gear oil's also. So I asked the service writer at the dealer how much it would cost to change the fluids in the rearends, trans, and transfer case. He told me that it already has synthetis gear oil in it. Is this true? If so when did jeep start doing this. Iwould prob help if you know that I am talking about a 2004 Rubicon. He said that all chrysler/dodge/jeep vehicals run synthetic gear oil.

 

[Snitty]

dont' you worry about going synthetic in the diffs

 

[jps4jeep]

You most likely have synthetic in the diffs, as well as a additive for the lockers.

I doubt you engine oil is "factory" synthetic, but it could be

 

[redrooster]

Better take a look at the owner's manual and see what is recommended. If your Jeep is that new I would stick to whatever is in it from the factory. I would give it some time as a "run in" period before switching.

 

[exjay33]

Run them in for a couple of thousand miles then switch too a true syn. like amsoil the others are not true syn. they are oil based products.

 

[Snitty]

i've heard nothing but good stuff about amsoil

 

[exjay33]

The red line oils are also a true sny. and are very good.

 

[TwistedCU]

we dont need no stinkin

synthetics

 

[Junkpile]

Keep the dinosaur juice in the diffs, unless you don't wheel in mud and water at all. It's too expensive to run in the diffs for a mudder where you have to frequently change it.
The most consistent advice I've been given is to break the engine in with regular and switch to synthetic after a few thousand miles. Fix any leaks you have before switching. Synthetic oil is thinner than it's counterpart, so any leaks will be more pronounced and would more than likely escalate.


I've got my own questions about using synthetic in manual transmissions and differentials. Am I crazy for assuming the thicker conventional oil would provide more cushion to meshing parts than the synthetic when shockloading, as when dumping the clutch? If true, wouldn't the thinner oil also be more likely to cause a parts failure in a situation where something like the crank or cam bearings were overly worn?

 

[west747]

i would agree with you in theroy junkpile. however with that being said i have notice a great improvment in my 5 speed after switiching it to syn. oil. less grinding and smoother shifts. now that could be because of the mess of white fluid that was in my transmission before tho. :roll: