I got new gears installed at 4 wheel parts and they said not to use synthetic gear oil with the new gears... and especially don't use it with the factory limited slip!

The dealership is the one that said I have to use synthetic with the limited slip.

Are they all nuts? Am I nuts? I thought synthetic would be superior

 

if i remember right if you use regular oil with a LSD you have to put in an LSD additive. I run Royal purple.

 

Yep, Synthetics have the LS stamp on the bottle. If you use regular, you need to find one that is compatible with a limited (don't know if any are?), or buy the additive. Not sure why 4wp told you not to use synthetics, but you will want to check into their gear warranty before ignoring the advice. (unless they were saying to run dino for the break-in, and then you can change?)
If for some reason they will only warranty the gears if you run dino, then run dino.

 

You don't want to use synthetics to break in new gears.

 

but after 15k miles it would be ok to change to synthetics?

 

Yes, it would be fine. For me personally, I stay away from synthetic gear lube.

 

so I have a sport, with the D44 rear and D33 front with no LS. Can I use syn? I was going to the mobil 1 diff oil in mine this weekend is this a no no then and go with regular?

 

Yup. Synthetics will work too well and the gears will never bed in.

 

FYI, not all Wranglers are Jeeps

Which is why in Canada it wasnt until 2007 that Jeep could call the JK a Wrangler, Previous Wranglers were called TJ and YJs in Canada
http://www.73-87.com/Special_Editions/wrangler.htm

 

As you guys are on the subject...
My JK's an 07 build 2.8CRD.
Changed front and rear axel oils and now get 2 - 3 more mpg and better acceleration ! ..... is this typical ?

RLT