Special diff fluid now standard?

[5soko]

So i know the m5 and m3 share the same issues and sib about the slow, tight turn, rubbing sound from the diff so maybe someone can help..

My car is making the rubbing sound when cold and turning to the right. So im going in for a routine service which includes the diff oil change.

My car is a 10/2008 build and a MY 2009 model.

Is the special diff fluid now a standard item or will they put the regular diff oil in my car again unless i complain and they put the sib special diff oil with additives to stop the rubbing sound..

[edwinm3]

They will only use the fluid it calls for which is the one that has the FM booster additive.

[5soko]

Originally Posted by edwinm3

They will only use the fluid it calls for which is the one that has the FM booster additive.

Awesome Thanks! so there isn't a such thing of using a diff oil from the older days that doesn't contain the FM booster? Because obv the SIB was released for cars making noise and using the standard oil. Has BMW switched over and made this additive oil now standard?

Just making sure that when I go in for my routine maintenance they don't put some standard type of oil in there and make sure they use the FM booster diff oil.

[jjw2331]

My dealer puts in FM booster diff oil regardless of noise. I had it in my diff after my 1200 mile service, again after a seal was replaced, and again after I got a replacement diff for a strange clunk that was not normal. Never did I complain about a grind, but I still got the FM booster fluid.

I asked my dealer for bottles of diff oil to change my own fluid last year. They gave me three bottles of 75w-140 diff fluid with FM booster. I know castrol saf-xj (now known as castrol syntrax limited slip) is the older fluid or what comes in our cars when brand new. So I asked for it and the parts guy said FM booster is only fluid we use on M differentials. I guess its the new standard fluid. But thats just from my experience.

[Vic311]

Originally Posted by edwinm3

They will only use the fluid it calls for which is the one that has the FM booster additive.

+1

[Fen335i]

I used the OEM diff fluid w/FM booster as well on my last change. My goodness it's expensive...I might try an aftermarket high-end fluid next time. The OEM stuff is highway robbery...kind of like the 10-60 TWS oil! At least now Redline is making 10-60 now that is slightly cheaper.

[5soko]

Originally Posted by jjw2331

My dealer puts in FM booster diff oil regardless of noise. I had it in my diff after my 1200 mile service, again after a seal was replaced, and again after I got a replacement diff for a strange clunk that was not normal. Never did I complain about a grind, but I still got the FM booster fluid.

I asked my dealer for bottles of diff oil to change my own fluid last year. They gave me three bottles of 75w-140 diff fluid with FM booster. I know castrol saf-xj (now known as castrol syntrax limited slip) is the older fluid or what comes in our cars when brand new. So I asked for it and the parts guy said FM booster is only fluid we use on M differentials. I guess its the new standard fluid. But thats just from my experience.

Thanks for that I appreciate it. Either way im gonna make sure that's what they use in my diff for my upcoming service!

Originally Posted by Vic311

+1

Originally Posted by Fen335i

I used the OEM diff fluid w/FM booster as well on my last change. My goodness it's expensive...I might try an aftermarket high-end fluid next time. The OEM stuff is highway robbery...kind of like the 10-60 TWS oil! At least now Redline is making 10-60 now that is slightly cheaper.

Yea im gonna use the OEM stuff on this service aswell. I like to stick with the oem stuff. Just needed clearing up on what exactly and if the FM booster is the standard now. Thanks.

[redline9001]

My car is a 2011 and had the diff noise, they just changed the oil the other day and the noise is gone.

[Bmw135er]

Originally Posted by edwinm3

They will only use the fluid it calls for which is the one that has the FM booster additive.

This is wrong. The FM booster is the only oil to be used in all M differentials for normal maintenance. It's been that way for almost 3 years now. If your car doesn't have it, the last dealer to service it used the wrong fluid.