waqas300

My Mechanic put ELF Gearelf 4 Gearbox oil 85W140 API GL-4
is that oil good for LS having 318K miles on it?

RA40

iTrader: (6)

There is some debate about compatibility on spec'd GL-4 and GL-5 with bearings, this remains mostly to trannies. Some discussions state that there is compatibility. This is not confirmed mutually between the makers of the fluids so it may not be a universal trait from one to another. In a differential, I don't have an answer other than following the manufacturer's recommended of a GL-5, 75/80-90 fluid. I would encourage a replacement with the proper spec'd fluid.

gebo

If you are using a synthetic fluid with the proper specifications, I would see no need to add anything to it. I can see adding Lube Guard if I were using a Dino fluid but I don't see the point in adding a Dino fluid to a differential where you only change it every 75-100K with around 2 qts of fluid.

oldskewel

iTrader: (1)

That sounds bad to me. I forget the details, but because of the types of gears in a transmission vs. a differential, you want GL-4 in a manual transmission, and GL-5 in a differential or transaxle.

I would definitely change it out before long.

In my opinion ... brand does not matter, synthetic vs. non does not matter much, weight should be close to spec, but GL-5 is a definite must have.

waqas300

What to do now? Should i get it changed it immediately or wait until next differential oil change and put GL-5? What can happen if i keep running on GL-4?

gebo

Go to bitog and do a little research. oldskewel is 100% correct on the GL4 vs GL5. I'd differ with him on the synthetic but that is probably more of personal preference as I have no hard data to support my position. Just my guts! HAHA I'd change it out within a week or so. You can do it yourself as it is not hard. May have to buy a funnel, hose and tool but you will have them "forever." You tube how to change diff fluid. If I can do it, I know you can.

IF you are like me, you don't want to go back to your mechanic as you don't like confrontation. If you do it yourself, he will never know. Next time you change it, you can carry in your own gear lube to him to change it with. All is well!

But if you try to change it yourself, you may find out how easy it is and want to do it form now on....

waqas300

Okay i will put 80W-90 GL-5 in it as soon as possible. Thanks

oldskewel

iTrader: (1)

That sounds good. You may find 75W-90 more easily. I use that (Valvoline Synthetic, to be precise, since it was a good price). Also, you may see some marked as Limited-Slip-Differential (LSD) compatible. You of course don't have a LSD, but it is fine to use LSD-compatible oil in a non-LSD differential.

When you walk into to your local Pep Boys or whatever, the most common gear oil you'll probably find is 75W-90 LSD-compatible, so you'll have a lot of choices.

oldskewel

iTrader: (1)

+1 :-)

waqas300

I found GL-5 75W-85 Differential gear oil LT so i put that. I hope that works, and what does LT means? please check the attachment.

oldskewel

iTrader: (1)

That is good oil, but might have cost more than it needed to. It should work well for your application.
The LT means it is for a non-LSD. If you had a LSD, you'd need the Toyota LX oil.

waqas300

How to find out if the differential is LSD or not?

Gene01

All LS cars came from the factory with non-limited-slip differentials.

dicer

GL-5 has more EP Extreme Pressure additive in it than GL-4 and that is a good thing, if you want long differential life.

waqas300

i got the GL-4 drained out and got the GL-5