Has anybody ever used synthetic trans fluid in their transfer case. Im wondering if its worth the extra cost and if it has any negative effect on seals or other parts.

 

Synthetics are always better. Better for your particular situation is subjective.

 

Worth it to me.

100,000 rough miles and counting. Has no negative effect on anything and more than likely a very good positive effect.

 

I know that with synthetic engine oils the breakdown temperature is around double the actual operating temp of the engine, as regular "dino" oils breakdown AT the operating temperature of your engine which is bad. For a transmission i would believe that the same could be said for them. HEAT= your worst enemy for anything mechanical, so anything you could do to lessen damage associated with heat would be greatly beneficial. I personally run synthetics in my trans, power steering, engine, differentials and transfer case. I saw a little improvement in power and would imaging a large improvement in the amount of wear in said components. If you have failing components you will likely see zero benefit in adding synthetics, once things wear out and become damaged beyond a certain point there is no going back, so if your currently not having a problem with any of your drive train parts you would see a benefit of prolonged life from these components, if you are having mechanical issues, replacement is the only option and when you do replace, synthetics will help in the longevity of your parts. while your in there a trans cooler wouldn't hurt, as well as a gauge to monitor the temp of your tranny. I plan to do this upgrade soon with an A-pillar gauge and sending unit on the trans pan.