I went out and bought 7qts of 80/90w synthetic gear oil. Will this be ok to use on my P38s differentials? And when refilling how much do I put in?

Thanks in advanced.

 

Yes, that is what to use. When draining the fluid, check your magnetic drain plug for metal check, fine shavings are OK. Fill till the fluid comes back out the fill plug, apx 2 quarts.

 

Should be fine. Make sure it's suitable for both GL4 and GL5 applications.

From workshop manual:

Front Axles
From dry 1.7 litres / 3.6 US pints
Refill 1.6 litres / 3.4 US pints

Rear Axles
From dry 1.7 litres / 3.6 US pints
Refill 1.6 litres / 3.4 US pints

Regards

 

It was suitable for GL-5 applications but not GL-4... do i need to redo it now? lol

 

Hate to be the bearer of bad news and i'm not completely positive this is the case, so someone correct me if i'm wrong, but I believe that it needs to be GL-4 and GL-5 applicable because some GL-5 oils have potentially damaging sulfur in them.

I personally would replace it ASAP. Sorry!

Regards

 

It also says MT-1 on it and doesn't have any information that might suggest it has sulfur in it. But it does say "contains aliphatic hydrocarbons" and "recommended for all hypoid differentials" w/e all that means...

 

You've got me interested in this since I haven't replaced mine (not that I plan to til I have a problem but it's interesting).

You might be fine because it has to meet certain temp and stability requirements to meet MT-1 standards. However, knowing how picky Rovers are, personally, I would replace it and do it asap.

Any GL-5 oil should be compatible with hypoid differentials which perform under extremely high pressure. To do such, they typically have sulfur or other chemical additives that can be corrosive to metal parts which is why i'd find some Gl-4/GL-5.

Don't ask me about aliphatic hydrocarbons... it's been years since i've had any organic chemistry but that shouldn't effect it either way.

Regards

 

Ideally you are supposed to use synthetic, if not that is not a big deal, GL5 rated fluid is great GL4 will do, I run a GL6 because of my lockers.