Transmission and differential oil

[strictlyJDM]

Im going to be replacing my transmission and differential oil soon and wonder whats ideal for the components.

This is for a 540i 6 speed with the 3.15 LSD.

I already have three bottles of redline 75w-90, hopefully I can use it one or the other.

Let me know

Thanks

[5mall5nail5]

Im going to be replacing my transmission and differential oil soon and wonder whats ideal for the components.

This is for a 540i 6 speed with the 3.15 LSD.

I already have three bottles of redline 75w-90, hopefully I can use it one or the other.

Let me know

Thanks

I am using Redline D4 ATF and Redline 75w90 in a couple cars and really like it.

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[marct335i]

+1 on the redline 75w90 for the diff. I just installed an LSD in my 525 and used the RL and it's great. No howl or any noise. Smooth operation with traction when you want it.

[Psykick5]

Redline 75W90 for diff is pretty much the consensus. Also Redline D4 ATF in the transmission (yes, ATF in a manual transmission.)

[DrJomamachubby]

I have M1 universal ATF in my 530i/5's transmission. I'm happy with both the shift feel and the cold weather performance (probably not a consideration in SF, but whatever).

[strictlyJDM]

Sounds good guys,

Looks like i will be using the RL ATF for the transmission and the 75w-90 in the diff

Do you guys know how many quarts the tranny and diff take?

[5mall5nail5]

Sounds good guys,

Looks like i will be using the RL ATF for the transmission and the 75w-90 in the diff

Do you guys know how many quarts the tranny and diff take?

I believe 1.8 in each just about

[marct335i]

I believe 1.8 in each just about

1.7 med case 1.8 large case. Obviously a minor difference. Idk about the trans. The owners manual has all capacities.

[TGreene]

With the LSD, don't you want to use that LSD addititive?

[5mall5nail5]

With the LSD, don't you want to use that LSD addititive?

Redline 75w90 has additive in it for LSD. If your LSD is "too grippy" and the cluthes chatter, then you can add an additive in that makes it less chattery. I have no issues, though.

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[strictlyJDM]

Redline 75w90 has additive in it for LSD. If your LSD is "too grippy" and the cluthes chatter, then you can add an additive in that makes it less chattery. I have no issues, though.

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I have a slight chatter from my rear diff but will using the additive make it less "aggressive" or just quite it down. I don't want the additive to dumb down the performance of the LSD.

[5mall5nail5]

I believe it will make it perform a little less such that it stops chattering.

[strictlyJDM]

I believe it will make it perform a little less such that it stops chattering.

chatter isnt to bad anyways so ill just go 100% fluid.

[strictlyJDM]

What size is the diff drain and fill bolt? Write ups say 14mm Allen but that seems huge. Mine is a fairly small Allen size

[Tj Hunter]

No Royal Purple love in here? That is what I have used in all the BMW's that I have had. I LOVE RP, seems to be a little quieter and lasts longer then Redline. I had Redline filled in the trans and diff of my M5 when I bought it at 89000 and I had a noticable chatter from the LSD after 20K miles...I did not track, burn out, drifto, etc just normal DD senerios, that IMO is WAY too short of a life for additives.

[strictlyJDM]

I'm using RP in the engine if that makes you feel better!

[5mall5nail5]

What size is the diff drain and fill bolt? Write ups say 14mm Allen but that seems huge. Mine is a fairly small Allen size

Yeah sounds huge but it is actually 14mm. An allen wrench may not work because the 90 degree might keep it from fitting between the diff and the subframe. You need to cut a piece off about 30mm and use an open end wrench over it - it worked great for me that way.

[strictlyJDM]

Yeah sounds huge but it is actually 14mm. An allen wrench may not work because the 90 degree might keep it from fitting between the diff and the subframe. You need to cut a piece off about 30mm and use an open end wrench over it - it worked great for me that way.

was there ever a switch over to a small size? my doesnt seem like it will fit a 14MM. Ill pick one up just incase and try it out once I have time to get under there. Going to do the trans and diff at the same time. Cant wait to see if there will be any improvements over the old fluid.

[5mall5nail5]

I am not sure - everyone I've seen is 14mm. Its a big plug - maybe 3/4" diameter so I am not sure you'd want to put a smaller allen key hole on there.

[Tre0Tre34]

I am definitely a fan of royal purple. Put the syncromax in my tranny about a month ago and it made a huge difference in the smoothness with which it goes into gear. No problems with the single digit mornings we've been having this week either.

[jfj707]

was there ever a switch over to a small size? my doesnt seem like it will fit a 14MM. Ill pick one up just incase and try it out once I have time to get under there. Going to do the trans and diff at the same time. Cant wait to see if there will be any improvements over the old fluid.

Yeah, some were 10mm.

[jehu]

No Royal Purple love in here? That is what I have used in all the BMW's that I have had. I LOVE RP, seems to be a little quieter and lasts longer then Redline. I had Redline filled in the trans and diff of my M5 when I bought it at 89000 and I had a noticable chatter from the LSD after 20K miles...I did not track, burn out, drifto, etc just normal DD senerios, that IMO is WAY too short of a life for additives.


I put some RP Max ATF in the Getrag a few weeks ago and it 100% cured the popping out of Fourth issue I've had.. 100%...hasn't popped out of any gear even once. I'm not saying no other ATF would have done it but Red Line isn'treadily available anywhere near so I used what was within arms reach ..

[strictlyJDM]

Yeah, some were 10mm.

thats more like it...i was at the store today looking at the 14mm and in my head i was hell no this is way to big. Looks like ill be getting the 10mm