Hi Guys and Gals, This is my first crack at JK-Forum. I would like to thank the administrator for this web site its been a great resource for a guy who isn't that mechanically inclined but is willing to try and loves Jeeps, especially the JK's.

I took a look at the write up on how to change the oil from the tcase and man. trany, but I would like to put synthetic in. First is the mopar oil synthetic? Second I am switching because of our cold winters in northern Canada and our hot summers, be it short ones. And I like the thought of the overall better performance of synthetic oil. Any thoughts on this? What type would I use?

Thanks

 

I do not believe the stock stuff is synthetic. I went with Royal Purple Syncromaxx for the trans and Royal Purple ATF (i believe thats the name) for the Transfer Case because it calls for ATF+4

 

I went with Amsoil synthetic manual synchromesh for the trans and Amsoil ATF+4 for the T-Case. With the factory oil it was hard to shift for the first 10-15 minutes.

You should also change the Diff oil for synthetic too. I put Amsoil Synthetic SVG 75W-90. With the factory oil at -20 degrees the first few miles you feel like you are towing another JK behind you.

I also put Amsoil synthetic XL 5W-20 for the engine.

I live in Northern Quebec and it drops below -25 most of the winter.

i'm sold to Amsoil products and it's a little more expensive. Royal Purple, Mobil 1 or other synthetic brands are better than dyno stuff anyway.

I lived 2 years in the NWT and fly to and from Edmonton twice a year. I know how cold it gets there

 

You'll get many diff opinions on this......so be ready! I used Castrol Synthetic ATF+4 in my transfer case and auto tranny, Mobil1 in my axles. Also use Mobil1 in my engine. My reason is reputation and availability....both are time proven major brands and easy to find at most stores. I'm not taking anything away from the other brands, these just worked best for me.

 

Thanks for the advice guys. I do around 60k km/year and was about to change those oils. Every thing else is synthetic but wasn't sure if the trang and tcase where available in syn. Thanks again
Paul