.. need help on what oil to put in my grand national differential.

[Buickfan]

i have 75W-140 synthetic laying around my house is that good??? or which one am i supposed to use and how many??

thanks ruben

 

[Squid4life]

I think I used two pints of 75w90 Synthetic Mobil 1. the 140 is really thick, I used it on my powerstroke diesel truck. I think too thick for these cars, but could be off.

 

[Buickfan]

I think I used two pints of 75w90 Synthetic Mobil 1. the 140 is really thick, I used it on my powerstroke diesel truck. I think too thick for these cars, but could be off.

thanks a lot squid4life.

Ruben

 

[williamsGN]

Dino, no synthetic to keep your differential alive.. been discussed many times before.

 

[turbo nasty]

I would steer clear of synthetics in our clutch type posi cars. In fact a new Eaton comes with a Bright labeled that says to not use Syn as it will hamper clutch operation.

Dino gets my vote!!

 

[Squid4life]

hmmm... need to check my notes. Too many cars to keep track of what went into which one...

 

[ronbuick]

dino oil with additive if you got posi, thanks

Ron

 

[Buickfan]

thanks a lot for the help guys.

Ruben.

 

[RIFF RAFF]

Or castrol 80-90 GL5 hypoid .. Needs no additive ..THE 75 -140 IS USED IN FORD EXPLORERS AND SUCH