Differential Gear Oil

[Victor_PR]

Hi everyone;

Any other opinions as to what diff gear oil is best for our cars? I searched and found Valvoline Durablend 80W 90 Synthetic Blend. My car is a stock 325i automatic. My diff is showing a leak so I bought a new gasket from another r3v member. But as I wait for the gasket, I wanted to know what you all recommend.

I searched and found a Pelican article that used Royal Purple.

What should I look for when buying diff gear oil?

Also, any write-ups as to how to replace the gasket?

Thanks in advance guys!

[agent]

I have Mobil 1 75W-90 in Klaus' 3.73 and Redline 75W-90 in Lola's 3.15.

[Nowayman]

I've been using Mobil 1 75w-90 in my cars as well.

[slammin.e28]

Redline 75w90.

/thread.

[blunttech]

slammin knows his lube. he has to. Redline

[slammin.e28]

slammin knows his lube. he has to. Redline

You better believe it. I have gallons of it behind me every day.

[mcr_driver]

Used both mobil 1 and redline with no issue's on my diff's. I'd probably go with redline again and will probably be doing so soon actually.

[ELVA164]

Redline 75w90.

/thread.

Just pay attention to if it's a LSD or not because some oils include limited slip additives and some require you add it on your own.

[slammin.e28]

Just pay attention to if it's a LSD or not because some oils include limited slip additives and some require you add it on your own.

Red Line 75w90 has the LSD additive already in it.

[Victor_PR]

Just pay attention to if it's a LSD or not because some oils include limited slip additives and some require you add it on your own.

I know this will reveal my real ignorance when it comes to these cars but I have to ask: How do I know I have a LSD? Did automatics come with LSDs? If I were to put Redline and my diff is not LSD, will I harm it?

[mcr_driver]

It wll have an S stamp on the bottom of the diff or a metal tag such as 3.73S or 2.93S the "s" designating it as a limited "slip" differental. Otherwise you could do the burnout test...:evil: There are other ways as well but burnouts seem to be the most fun to do

[slammin.e28]

I know this will reveal my real ignorance when it comes to these cars but I have to ask: How do I know I have a LSD? Did automatics come with LSDs? If I were to put Redline and my diff is not LSD, will I harm it?

Lift the back of the car up (so both rear tires are off the ground) and spin one wheel. If the opposite wheel spins the same way, you have LSD. If it spins backwards, you do not have LSD.

No, won't harm the diff.

[mcr_driver]

Lift the back of the car up (so both rear tires are off the ground) and spin one wheel. If the opposite wheel spins the same way, you have LSD. If it spins backwards, you do not have LSD.

No, won't harm the diff.

read as, the no fun way :rofl:

[Victor_PR]

It wll have an S stamp on the bottom of the diff or a metal tag such as 3.73S or 2.93S the "s" designating it as a limited "slip" differental. Otherwise you could do the burnout test...:evil: There are other ways as well but burnouts seem to be the most fun to do

Thanks for the clarification! I'll creep under my car and have a look.:)

[slammin.e28]

read as, the no fun way :rofl:

Lol, I know, I know, but so many times the tags are all corroded away, or missing, and the "S" on the bottom is not visible anymore.

A friend though he had a 3.73 LSD in his car for the longest time. Finally took it out to put in a 4.10 LSD, drained the fluid, peeked inside, and SURPRISE! Open gears.