Very importian question here im looking to do a serivice on both my front and rear differntial how much fluid would i need for each truck is an 03 silverdo 1500 5.3l do they have a gasket or do you just use rtv

 

Mine is a 99 5.3 2wd and it took about 2.5 bottles for the rear after the tru trac and 373 gears install. I think it would be safe to just top it off. I am about to change the fluid on my rear end and I bought 3 bottles since it will be broken in Saturday but I am no expert.

 

I just got in from changing my rear end oil after the 500 mile breakin period. Took 73oz of 80-90 for the rear on my 2wd. Its 2.5 bottles. Buy six bottles and top it off.