Rear Axle Leaks w/ synthetic?

[Heavyvan]

Has anyone experienced leaks at the rear axle when using the synthetic gear lube? I'm ready to change my lube but still deciding whether to use the 75-90 synthetic or the 80-90 regular. I have the special RTV for the diff cover, but i'm more concerned about getting leaks at the pinion and / or wheel bearing seals. I have a 99 with 95000 miles. A TSB came out in 98 where they recommend the synthetic, but I think it's only to improve gas mileage.

HV

[Dodgevanman]

I personally recommend this:

http://www.lucasoil.com/products/display_products.sd?iid=43&catid=4&loc=show

good stuff!

[DANVAN]

I use moble 1 synthetic, no leaks.