i just got back from jiffy lube, had my tranny flushed and my diff flushed. boss wouldnt let me do it at work, and i dont have the tools here. however, they told me that synthetic 75-90w or whatever synthetic gear oil is REQUIRED for it to operate. is this true? if so, then they were honest to me, if not, they just lost a customer, they charged me an extra 35 bucks for the oil. can anyone help?

 

Marlin told me 75-90 gl5 gear oil. i run castrol. some people swear by syn.

 

Its jiffy lube, they were trying to sell you stuff.

Plain old oil is fine.

 

Umm yeah regular dino oil is fine...

 

ABSOLUTELY NOT TRUE. It's o.k. to use it, but it's NOT REQUIRED.

API GL-4 or GL-5(GL-4 preferably)
SAE 75W-90

http://personal.utulsa.edu/~nathan-b...21lubrican.pdf

 

thats what i thought. and no refunds eh... oh well. theyve lost a customer.

 

Use GL-4 gear lube in your manual transmission. Use GL5 for your transfer case and front/rear diffs.

 

yeah. oh well, looks like im stuck with this synthetic stuff for 30,000 miles, i dont think jiffy lube does refunds... though i plan to tell the manager that hes an a.... something thats colorful, but i cannot say on here. and im going to tell him if he doesnt refund the 30 dollars he screwed me out of, he has lost a customer. i know one customer doesnt sound like much, but still, greed factor might work.

 

While not required, I would at least use synthetic in transmissions, and transfer cases.

I'd do it in the diffs to, if you have breathers. Otherwise, you'll probably ruin expensive oil often.