ok so i have searched a bunch and shopped a bunch. here is what i have...

99 5 speed dana 80.

i have a new mag hytech cover im putting on. All i do is tow with the truck. It sees maybe 8000 miles a year. loads no more than 7k

i read that 75/140 will work fine.(cant seem to find that anywhere other than wallymart in just the quart synthetic. i do not have a limitied slip or at least it doesnt work. What if i put in 85/140 as i have a bunch of that here already.......whats the difference between those 2?

thanks, jiMMy

 

I can't tell you about the weight of the oil, but just make sure whatever you use is GL-5 rated.

 

Check your Vin # for posi info.
As for Gear Lube: LubeMaster (800 527 9929) ask For Rick Martinez.
It ain't cheap, but the best never is.
The ligher weight should work with no problem and the quanity you have to buy will last you and the truck forever.

 

welp went with 85/140. took about 7.5 quarts. lovin the new cover.. only thing is that the PO had a diff temp gauge(my x monitor said oil temp) i just thought it was motor oil. lol... the sending unit didnt fit in the hole on the mag cover so i just tied it up for now untill i get a small sending unit..

jiMMy

 

Mag cover operation may have the adapter you need, give'm a call.