I picked up this gear oil from Wally World to do my diff's. I know it's a different weight, but I was told it will still work, but anyway, what does this "GL-5" mean??

[IMG]local://upfiles/57704/7357B16B5EE5457A8575781C702CC810.jpg[/IMG]

 

I believe GL-5 is a API classification. It means that the oil meats certain standards to be classified as GL-5

 

Does that mean this is ok to use for our trucks

 

Check your owners manual. I think GL-5 is OK.

 

Reading the owner's manual and the service manual, they're pretty convincing they want a synthetic lubricant. When we did the 15k on my dad's '06 3500 we used a 75w90 Mobile-1. GL5 is as previously stated isa classification for API extreme pressure gear lubricant, keep in mind there are serveral quality levels within the GL5 classification, I do not know who supplies Wal Mart with their lubricants, I would hesitate to use SuperTech in my truck. Using a well known synthetic 75w90 (valvoline, mobile1, etc.) would be my suggestion, but again it's just me. Best of luck.

 

Well I went ahead with the SuperTech dino oil, we'll see how it works. Anyone else have any other opinions?

 

From what I've heard SuperTech is an off-brand of Quaker State. Supposedly on the back of the container it says that its manufactured by them. Havn't checked it myself and could be wrong, but hey you got it right there and could always look. And as far as what Tony said, there are different lvls, but if it has the API cert. it at least has the minimum amount of additives that they require. More expensive brands in theory should have more additives.

 

I've heard that too, I don't know if anyone really knows who makes it, I'll check the back though. It's definitely made by a bigger company though.

Anyone know, do you have to put synthetic in the diff, 'cause I didn't.[:@]

 

[Deleted by Admins]

 

Thats's my question, is there supposed to be synthetic in there, do they only recommend it or doesn't it matter? If so, what is the difference between the two that they want synthetic, what is so much better about it. I tow my boat which is about 2-3k and have a flat bed utility that weighs 1400 empty, plus whatever I put on it.