Confusion regarding 6mt trans and diff fluid change at 30k

Guys,

I hope you are doing well. My car is coming up on 30k miles and I am not clear on whether the transmission and differential fluids need to be changed. I know they were changed at the 1200 mile break-in service, but based on my reading of the manual I am not sure if the transmission and differential fluids need to be changed.

I've searched the forums and some threads indicate lifetime fluids while others say the fluids need to be changed at 30k.

This thread below indicates the 30k service, but it doesn't seem like the transmission fluid was changed though the differential fluid was changed.

http://www.m3post.com/forums/showthread.php?t=472478&highlight=30k

I would appreciate any inputs based on experience.

Thanks.

It should be changed, and the maintenance manual on my '08 specifically calls for both fluids to be replaced every other oil change called by the CBS computer, which is every 30K miles at the most. But I also read that BMW was changing his tune to extend that to 60K miles. Just like most owners change engine oil every 7.5K miles on their own, I'd do the same with the tranny and diff if dealer doesn't want to do it at 30K anymore.

I just changed both myself with Royal Purple at 7K miles, but because I wasn't happy with either one (diff was chattering and tranny was too notchy, especially when cold). RP solved both issues. Well, the tranny not completely, but made it as best as it's going to get (most manual trannies are a bit notchy on the 1-2 shift, and that's the only issue that remains to some degree), which is perfectly acceptable to me now. And much cheaper than stock fluids too . Good luck.

^^^ Great Response!

I will be sure to get both of them changed at 30k regardless of what the dealer recommends.

I just had the 30K service done as well. They did not change the transmission fluid but did change diff lube... I have a call in to BMW-NA to confirm that my service manual is now "incorrect" stating that the two are to be done together. Will keep you all posted when I hear back.

any update on this? Specifically, what does BMW recommend for the interval on the diff fluid change? My SA told me @ 30k, but this link mentioned it briefly that it needed to be done at 1200 break-in service:

http://www.m3post.com/forums/showthread.php?t=265139

I think this was misinterpreted?

mdosu wrote

any update on this? Specifically, what does BMW recommend for the interval on the diff fluid change? My SA told me @ 30k, but this link mentioned it briefly that it needed to be done at 1200 break-in service:

http://www.m3post.com/forums/showthread.php?t=265139

I think this was misinterpreted?

BMW says:

Transmisison, engine, differential is to be done at 1,200 miles.

Then engine at "up to" 15,000 miles (may be sooner depending on driving habits, your iDrive will tell you).

Then transmission, engine, differential at "up to" 30,000 miles.

I personally do an oil change at least every 7,500 miles or 5 track days, whichever is first.

^so I just found out my rear diff was not changed at 1,200, so I'm entitled to it, and I will demand it on my next oil change. Dag nab-it!

LateBraking wrote

BMW says:

Transmisison, engine, differential is to be done at 1,200 miles.

Then engine at "up to" 15,000 miles (may be sooner depending on driving habits, your iDrive will tell you).

Then transmission, engine, differential at "up to" 30,000 miles.

I personally do an oil change at least every 7,500 miles or 5 track days, whichever is first.

Apparently BMW no longer specifies transmission and differential fluid changes after the 1,200 mile break in. I was just at the dealer debating this.

pbonsalb wrote

Apparently BMW no longer specifies transmission and differential fluid changes after the 1,200 mile break in. I was just at the dealer debating this.

Well, that's bullsh*

I better check my invoice to see if my diff fluid service was done as well, I've been attending way too many track days for it to not have been done.... I just assumed that the dealer would, as it was done properly on my 2008....

LateBraking wrote

Well, that's bullsh*

I better check my invoice to see if my diff fluid service was done as well, I've been attending way too many track days for it to not have been done.... I just assumed that the dealer would, as it was done properly on my 2008....

never assume the dealer will do the right thing

unless you know the tech/SA personally

persian54 wrote

never assume the dealer will do the right thing

unless you know the tech/SA personally

Good point.

My 1-2 shift is slightly notchier than any other shift, so I have asked the dealer to drive the car with me when they change the engine oil later this week. If the dealer refuses, I will chage the diff and trans fluids myself. Once every 30k miles is not a big deal at the rate I drive these days.

LateBraking wrote

Well, that's bullsh*

I better check my invoice to see if my diff fluid service was done as well, I've been attending way too many track days for it to not have been done.... I just assumed that the dealer would, as it was done properly on my 2008....

I just checked the 'Service and Warranty Information' booklet because I was wondering about this. There is no place in that booklet that I can find that talks about diff or tranny fluid changes other than at the 1200 mile service. If anyone can point out where I might be missing something, please let me know.

Dave

bump

abehwang wrote

bump

Why the hell are you 'bumping' this thread? Just read the freaking maintenance manual and see what's recommended. Oh, and dealer doesn't even have to follow that, if BMW made changes, like with the low-mileage oil change and air filter. Ask dealer, and if you don't like it, do it yourself. I do all my maintenance out of pocket so I don't have to deal with the only dealer in town. You have a choice too. Good luck.

elp_jc wrote

Why the hell are you 'bumping' this thread? Just read the freaking maintenance manual and see what's recommended. Oh, and dealer doesn't even have to follow that, if BMW made changes, like with the low-mileage oil change and air filter. Ask dealer, and if you don't like it, do it yourself. I do all my maintenance out of pocket so I don't have to deal with the only dealer in town. You have a choice too. Good luck.

I was bumping in order to see if there were any changes/alterations made by BMW/dealer since my manual seems to be outdated (2008). Thanks though

"read the freaking maintenance manual and see what's recommended. Oh, and dealer doesn't even have to follow that,..."
Sadly very, very true. I ended up just buying a 5L. jug & changing the trans fluid myself. It seems that the "free maintenance" schedule is subject to change/interpretation. Hey, I should start a new "Lifetime Life Insurance Policy" sales program!