I'm about to change my differential fluid in my 1994 4.0L ranger and want to make sure I have the right stuff. The owners manual specifies M2C154-A and I have no idea what that's equivalent to. I have some 80W-90 Valvoline Gear Oil. Is this the right stuff? I also got the additive for the L/S axle to add. Thanks in advance.

 

Also is it okay to use a gasket instead of RTV?

 

The Valvoline gear oil is fine.

 

Use RTV. If you used a gasket, you'd still need to use a gasket compound anyway, so just save the unnecessary step.

 

rockledge,

i am planning to change my rearend fluid too. i was looking a the mobile 1 synthetic but they only had 75/90. would that be alright for a differential?

 

I changed the rear end oil in my 94 4.0 4x4 supercab yada yada etc 2X so far. First time I used Permatex black and all was well. Ford didn't even offer a gasket. All was fine. Then I changed rear end oil for a second time and I found out Napa had a gasket. BAD MOVE. I installed it and shortly after doing so the rear end cover cracked as evidenced by a leak. I'd strongly suggest using the OEM method; use Permatex black and save yourself a headache

 

75W-90 syn is fine as a replacement for 80W-90. Check your owners manual first, because some of the newer trucks use 75W-140.

 

Thanks everyone. I got it all changed. I ended up using RTV (permatex orange colored). Having this forum really helps. Thanks again.