ok i just changed over my diff to the t2 diff i had sitting in my parts car. that diff has not moved in well over a year. so i put it on and my buddy said "you should change that oil in there" to me he made a great point. now my question is what oil do you guys use in the t2 s4 rear diff? i am not worried about the brand. because here i see m1 and royal purple and some other. i am going to go under the car now and learn where the drain and fill plugs are

 

ifs it's limited slip (when rear wheels are in air and you turn one wheel forward, if the other goes the same way, its LS, if not, its regular diff) anyways, if it is a LS, royal purple has the additive already in it, the max gear 75w-90 is good to use, you can use it even if its not LS

 

Anything that meets API GL-5 spec.

 

yeah its an lsd, its from an s4 t2 i am going to the auto store tomorrow and i am going to ask them what they think also

 

it needs to be limited slip. you can either buy regular 80/90 gear oil and add the limited slip additive, or buy oil that already has the additive in it. either way is fine

pat

 

ok kool i will ask them for that thank you sir!

 

Ask an autostore for an opinion? Thats like asking a secretary to perform brain surgery.

The rearend needs a GL5 lube. 75w90 is what I prefer. If you are power modded, upping to a 110wt or 140wt would provide a little more protection.
I also prefer full synthetics. But, buy what you can afford.
I change my gear oils every 2-3 years OR evern 20k-30k miles, whichever comes 1st.


If you have an LSD(clutch/cone friction type), you'll need LSD additive. Some gear oils come with it already(read the bottle).
20 year old LSDs tend to be worn out and will sometimes tolerate not having any additive. Too little LSD additive and you'll feel the noise, shudder, grabbiness...... of the diff. Dose the additive only as much as needed. If you're using M1, RP, Ams, or RL full synthetics, you probably won't need any.

Remove the fill plug before you remove the drainplug.

 

yeah i have more power then stock pushing 330 hp right now that is why my old na diff broke. thanks for the heads up man very insightful! i went to mazdatrix and they have one there name NEO is that a good one to get? i am going to look for 110wt to see what i find. i know at my store i have for motorcycles 85/90wt but its not for lsd its for motorcycles

 

If you can't find a 110wt(new recent SAE spec), simply 50:50 mix the 90wt and 140wt of the same brand together.

 

ok kool i am going to the speed shop tomorrow and get some since i am going to be working on the car i might as well do that too

 

I use Royal Purple. You can get it at most parts stores now. Good stuff.

 

i am a bit scared of royal purple. i know of to many tranny's that got messed up using royal purple. one guy was using royal purple and the gears where just shifting bad, he put wal mart 99 cent bottles of tranny fluid in there and the noise never came back! so i don't know about that

 

Redline is good stuff too. I use it in the trans and diff. No complaints.