I'm putting in an order for some Amsoil products for my drivetrain but I'm curious what the "w/ TT" means in the following...

Standard Differential, Rear 8.25-9.25 W/ TT......GL-5

There's also...

Standard Differential, Rear 8.25-9.25 W/O TT......GL-5


The difference here is the weight gear oil I need to buy.


Also, can someone explain the difference between a 8.25 axle w/ a 3.55 ratio and a 9.25 axle w/ a 3.55 ratio?

My truck is supposed to have the heavy-duty service/tow package and I'm trying to learn more about this kinda stuff. On the axle, I have 9.25/3.55. I'm just not sure exactly what that means in english. ;-)

 

the 9.25 gear is larger diameter ring gear. will handle lots more power. but still not more than 450hp. a dana 60 will take 600 -650 hp, hemi type power.

 

Finally got around to calling Amsoil. The "TT" denotes the towing package.