Rear Differential Noise When turning at Low Speed

[BMWM.D.]

Originally Posted by GregW / Oregon

Invoice says MTF-LT-2; they say that is correct. They also say the LSD conditioner is already in it.

MTF-LT2 is the manual trans fluid, not the differential oil. The diff oil used during the 1200 mile service is the same oil BMW has been putting in all ///M cars since I have been involved in working on them. I don't have the part# handy, but it is a limited slip gear oil and is correct for the car.

If you are experiencing the grind noise during slow, tight cornering, then there is an updated fluid that can be installed to eliminate the noise from the clutches in the diff. Usually, this noise goes away as you break in the clutches. The more cornering you do, the quicker they will break-in. My E90 has never made this noise, but I have definitely broken in the rear differential

The fix is not an additive; it involves draining the current oil and filling the differential with a different fluid that contains a special friction modifier. The SI B on this subject pertains to all current ///M models ( E46,E6X,E9X and E85/86)

Oh, and I have heard this noise first hand in some of my customer's cars. It sounds like one of the rear tires is rubbing the fender or body in the rear (even though it is not). It can be pretty loud at times.

Hope this clears it up,

Andy

[von_zoom]

Thank you very much Andy. I will share your post with my Service Advisor next week.
vz

[SenorFunkyPants]

There are around 10 different makes of oil certified for use in this diff, but the one quoted in the Service bulletin is Castrol SAF-XJ which contains friction (slip) modifiers. It is this oil that is regarded as being the most effective are resolving the noises made by the diff clutch pack.

[Subw00er]

Having come from Vettes where this is normal, GM recommends a small bottle of the differential additive. Its gets rid of the problem.

[BMWM.D.]

Originally Posted by SenorFunkyPants

There are around 10 different makes of oil certified for use in this diff, but the one quoted in the Service bulletin is Castrol SAF-XJ which contains friction (slip) modifiers. It is this oil that is regarded as being the most effective are resolving the noises made by the diff clutch pack.

Actually, that is not correct. The SAF-XJ oil is the regular oil that is specified for use in the M3 as well as just about every other newer BMW. This is the oil that would be used during the 1200 mile run-in service. This is technically a "limited slip" oil. This oil is part# 83 22 1 470 080.

There is a special differential oil that is available to reduce clutch noise on the M models. This is the oil that we have been discussing in this thread. The part# is 83 22 2 282 583. It comes in 3 small bottles and is only used when a grinding/rubbing noise is reported. The regular XJ oil is drained and this oil is installed.

Andy

[chris719]

For what it's worth, I had this noise with my Z4M and it disappeared after 2000 miles.

[SenorFunkyPants]

Originally Posted by BMWM.D.

Actually, that is not correct. The SAF-XJ oil is the regular oil that is specified for use in the M3 as well as just about every other newer BMW. This is the oil that would be used during the 1200 mile run-in service. This is technically a "limited slip" oil. This oil is part# 83 22 1 470 080.

There is a special differential oil that is available to reduce clutch noise on the M models. This is the oil that we have been discussing in this thread. The part# is 83 22 2 282 583. It comes in 3 small bottles and is only used when a grinding/rubbing noise is reported. The regular XJ oil is drained and this oil is installed.
Andy

83 22 1 470 080 is SAF-XJ in a 55gal drum
83 22 2 282 583 is SAF-XJ in a 1 ltr pack

[SenorFunkyPants]

Originally Posted by Subw00er

Having come from Vettes where this is normal, GM recommends a small bottle of the differential additive. Its gets rid of the problem.

Not at all to be recommended. The diff clutch pack is designed to operate with high levels of friction between the plates, putting additives into the diff oil may degrade the friction level such that the Limited Slip part of the Diff would no longer function correctly although it would at least be quiet.

[foosh]

Originally Posted by SenorFunkyPants

Not at all to be recommended. The diff clutch pack is designed to operate with high levels of friction between the plates, putting additives into the diff oil may degrade the friction level such that the Limited Slip part of the Diff would no longer function correctly although it would at least be quiet.

However, he was correct. That was the solution provided by GM for the C6. They recommended a GM-branded additive only (name escapes me at the moment). Not all diff. additives are created equal, and I think you are also correct that some additives could compromise the proper function of the LSD.

FWIW, GM also stated that it was OK to take no action, but like here, many complained about it. They decided to address it with the additive if a customer wanted it attended to.

[SenorFunkyPants]

Originally Posted by foosh

However, he was correct. That was the solution provided by GM for the C6.

Fair comment...I should have been clearer and said not to be recommended for the M3 diff as it might not be suitable.
Certainly the diff on my M3 is noisy taking sharp turns when cold but its fine when warm and so I don't intend to take any action.

[BMWM.D.]

Originally Posted by SenorFunkyPants

83 22 1 470 080 is SAF-XJ in a 55gal drum
83 22 2 282 583 is SAF-XJ in a 1 ltr pack

The two are different oils. The SAF-XJ is the standard oil we install during all 1200 mile services. We carry it in a 55 gallon drum. I verified all part numbers before performing my own 1200 mile service. I just wanted to be certain we were using the correct oil. This is the standard oil listed by BMW in the "operating fluids" section of BMW's technical information. This oil is also available as a 1 litre bottle, part# 83 22 1 467 993.

The "specially formulated differential oil" (83 22 2 282 583) is the fluid listed in the Service Bulletin to use when the regular SAF-XJ oil results in excessive clutch noise. I know this because I have performed this bulletin on several cars. This oil contains additional friction modifiers to reduce noise.

Although I know they are different oils, I can provide you with one particular incident that stands out in my mind. I have an E90 M3 customer that asks for me to personally work on his car whenever he needs service. I performed the run-in service on his car right around 1000 miles, using the SAF-XJ oil in the 55 gallon drum. A few weeks later, he comes in to talk to me about a loud rubbing noise he is hearing while turning into his driveway. I tell him it is most likely the clutch pack in the rear diff. After a test drive, it is certainly the differential, and it was LOUD. I drained the SAF-XJ oil and filled the diff with the special #583 oil. A quick road test later and the noise was completely gone. This is enough to prove to me that these are different oils.

I could be completely wrong, but having first hand experience with this stuff for years, I really don't think so. I am not trying to be argumentative; I just want people to be getting the most accurate info.

Andy

[SenorFunkyPants]

I'm all for getting the right info, I got most of mine from Castrol technical support but if I can get through to them again I'll double check on monday.

[BMWM.D.]

Originally Posted by SenorFunkyPants

I'm all for getting the right info, I got most of mine from Castrol technical support but if I can get through to them again I'll double check on monday.

Could be a misprint in Castrol's catalog. I just double checked the listings supplied by BMW to all dealership service departments. While I don't have one of the bottles of the "special" oil in front of me, I do have some at work. I don't remember there being a Castrol label anywhere on the bottle, though. I'll look at it tomorrow. The 55 gallon SAF-XJ oil comes in a green Castrol drum.

Hey, maybe BMW is pulling the wool over our eyes and I've been filling people's cars with the standard XJ oil when they come in for a noise concern . I do not think this is the case based on my successful results using the "special" oil.

Andy

[SenorFunkyPants]

I had my first discussions with Castrol Tech support in 1997 about Castrol SAF-XJ (for use in the noisy LSD of my 911 turbo) and still have my hand written notes which say he is sending me to try: "4 ltrs of SAF XJ full synthetic APi 75-145 GLs for LSD with Friction Modifiers".
I had another conversation with Castrol when people first had their troubles with noisy E46 diffs and IIRC the same SAF-XJ that I had in 1997 was recommended for the E46 M3s.
I guess it could be that BMW and Castrol made arrangements to produce a custom oil for the M3s diff but I would have expected them not to use the same designation of SAF-XJ which serves only to confuse. But it would be best to be sure, so that everyone has the right info.

[foosh]

Originally Posted by SenorFunkyPants

Fair comment...I should have been clearer and said not to be recommended for the M3 diff as it might not be suitable.
Certainly the diff on my M3 is noisy taking sharp turns when cold but its fine when warm and so I don't intend to take any action.

I don't intend to take any action on the M3 either, and I didn't take any action when it occurred in my C6 Z06 . It is normal.

[BMWM.D.]

Originally Posted by SenorFunkyPants

I had my first discussions with Castrol Tech support in 1997 about Castrol SAF-XJ (for use in the noisy LSD of my 911 turbo) and still have my hand written notes which say he is sending me to try: "4 ltrs of SAF XJ full synthetic APi 75-145 GLs for LSD with Friction Modifiers".
I had another conversation with Castrol when people first had their troubles with noisy E46 diffs and IIRC the same SAF-XJ that I had in 1997 was recommended for the E46 M3s.
I guess it could be that BMW and Castrol made arrangements to produce a custom oil for the M3s diff but I would have expected them not to use the same designation of SAF-XJ which serves only to confuse. But it would be best to be sure, so that everyone has the right info.

You are correct about the SAF-XJ oil. The XJ oil is a synthetic oil for limited-slip differentials that has some sort of friction modifiers in it. It has been listed in the BMW parts catalog/technical system as the oil to use in all vehicles with a limited slip differential. It was originally introduced for use in the Z3 roadster. It continues to be the only oil used by BMW dealers when performing a routine differential oil service. This is the same oil that was used in the E46 M3 and E39 M5 when they got their run-in services performed.

This is not, however, the same oil that is used for the repair outlined in Service Information bulletin 33 01 02. It was originally formulated to reduce noise on the E46 M3 in 2002, but has since been approved for use in all ///M cars that experience the grinding problem. Without having the bottle in front of me, I cannot say if they are still calling it SAF-XJ or not. I wouldn't think so, because like you said that would cause confusion. I am 100% sure that it is a different formula than the standard oil. I'm not sure what exactly they did, but it does greatly reduce the clutch noise vs. the SAF-XJ oil.

[BMWM.D.]

Alright, I have an answer to our questions. The "special" oil (83 22 2 282 583) is described on the bottle as "SAF-XJ + FM Booster". So, it is the same oil with the addition of some type of extra friction modifier or "booster".

[SenorFunkyPants]

Originally Posted by BMWM.D.

Alright, I have an answer to our questions. The "special" oil (83 22 2 282 583) is described on the bottle as "SAF-XJ + FM Booster". So, it is the same oil with the addition of some type of extra friction modifier or "booster".

Fair enough...I'll have a word with Castrol and see what they say.

[HPoint]

Originally Posted by BMWM.D.

Alright, I have an answer to our questions. The "special" oil (83 22 2 282 583) is described on the bottle as "SAF-XJ + FM Booster". So, it is the same oil with the addition of some type of extra friction modifier or "booster".

This is what my dealer put in for my 1200 mile service:
83-22-0-309-031
88-88-6-900-345

Are theses correct? Did they put in the wrong fluids?

[BMWM.D.]

Originally Posted by HPoint

This is what my dealer put in for my 1200 mile service:
83-22-0-309-031
88-88-6-900-345

Are theses correct? Did they put in the wrong fluids?

The "031" number is MTF-LTx fluid, which is correct for the manual trans. I'm not sure about that "345" number, though. The diff oil specified by BMW for the 1200 mile service should be 83 22 1 470 080 or possibly 83 22 1 467 993 ( same stuff but different # depending on how it is billed out).

I did not have much luck searching for that part#

[HPoint]

Originally Posted by BMWM.D.

The "031" number is MTF-LTx fluid, which is correct for the manual trans. I'm not sure about that "345" number, though. The diff oil specified by BMW for the 1200 mile service should be 83 22 1 470 080 or possibly 83 22 1 467 993 ( same stuff but different # depending on how it is billed out).

I did not have much luck searching for that part#

If the 031 is the MTF-LTx, I hope the 345 is the differential fluid???
Now I'm worried...

Appreciate you looking it up for me. Think I should go back?

[BMWM.D.]

Originally Posted by ;5141306

If the 031 is the MTF-LTx, I hope the 345 is the differential fluid???
Now I'm worried...

Appreciate you looking it up for me. Think I should go back?

You might just want to call and see if they can give you a detailed description of the diff oil they used. Maybe they used a SAF-XJ equivalent that is not made by Castrol; hence the different number. That is all I can think of.

Since the number you gave did not come up in any searches, maybe it is a number this particular dealer "made up" to enter the oil into their system. Although, that would not make sense since in order to bill BMW for the service, they want to see the correct part# for the particular application. The warranty department is pretty picky about these things, and its not like Castol products are hard to get.

I would either ask or drop by and have them show you what they put in. I would do it in a nice way, of course.