ok tranny and diff fluid time i think....

[elerner61]

Some longer term use feedback here on the MT-90. I would use it again. I can't say that it's noticably better than OEM but it definitely isn't worse in my tranny. I've got at least 3K miles on the fluid now and have used it well down below freezing temperatures. My overall summary on the Z4M transmission is that it just doesn't like being shifted below 2500 RPM, particularly when cold. The revs on this engine drop so fast that if you try and shift at 3K without holding the revs with the throttle you're trying to put it into gear at 2K.

[RobMCoupe]

I ordered Amsoil 75w90 MTF for my tranny. Still sourcing Castrol SAF-XJ. Looks like Nissan GTR and Mercedes AMG use the same fluid. BMW seem to only sell Castrol SAF-XJ + FM which is much more $$$.

[inTgr8r]

^ i thought you could get SAF-XJ from the dealer if you brought in a jug & they filled from their bulk barrel.
IIRC thats what Ron Stygar & others have done.

[beta]

All cars after a certain year are supposed to use SAF XJ + FM. The initial SIB didn't mention the Z4 specifically, but they amended it later.

AFAIK the kind with booster only comes individually and is expensive. Had to buy two sets of fluids: one for new gears, one for 1200 mile break in. Ouch.

[RobMCoupe]

Originally Posted by inTgr8r

^ i thought you could get SAF-XJ from the dealer if you brought in a jug & they filled from their bulk barrel.
IIRC thats what Ron Stygar & others have done.

I will check with my local dealer or indy shop.

[RobMCoupe]

Originally Posted by beta

All cars after a certain year are supposed to use SAF XJ + FM. The initial SIB didn't mention the Z4 specifically, but they amended it later.

AFAIK the kind with booster only comes individually and is expensive. Had to buy two sets of fluids: one for new gears, one for 1200 mile break in. Ouch.

My Insp II dealer filled with SAF XJ. There is no problem with my diff with grinding noise. It should be okay without FM which is much less $.

[beta]

Originally Posted by RobMCoupe

My Insp II dealer filled with SAF XJ. There is no problem with my diff with grinding noise. It should be okay without FM which is much less $.

The bulletin specifically points out that you should continue to use it. And AFAIK our cars came from the factory with the FM booster.

Note: Vehicles that have had the differential oil converted to this special oil should continue to use this oil whenever a service requiring the differential oil replacement is indicated.

[RobMCoupe]

Originally Posted by beta

The bulletin specifically points out that you should continue to use it. And AFAIK our cars came from the factory with the FM booster.

Note: Vehicles that have had the differential oil converted to this special oil should continue to use this oil whenever a service requiring the differential oil replacement is indicated.

My invoice for Insp II have PN # 83 22 1 467 993 which Castrol SAF-XJ. I see Castrol SAF-XJ + FM PN # 83 22 2 282 583 is only available for purchased. There are many discussions on this and most are running gear oil without addition FM.

[G80indy]

Running Redline all around:

Crankcase 10w60
Gearbox: D4 ATF
LSD: 75W140 GL5
SI-1 injector cleaner with Shell 93 v-power

Smoother than stock now.

[beta]

Originally Posted by RobMCoupe

My invoice for Insp II have PN # 83 22 1 467 993 which Castrol SAF-XJ. I see Castrol SAF-XJ + FM PN # 83 22 2 282 583 is only available for purchased. There are many discussions on this and most are running gear oil without addition FM.

I'm sure it's fine. As far as I know BMW didn't add the FM because of any failures, just that noise in the bulletin.

Was just pointing out that it came with +FM and for some reason BMW says to keep using FM. Weather it's so the noise doesn't come back, or if there's a material property I don't know.

But you know me, I always try to get the best for my Z

[RobMCoupe]

Originally Posted by beta

I'm sure it's fine. As far as I know BMW didn't add the FM because of any failures, just that noise in the bulletin.

Was just pointing out that it came with +FM and for some reason BMW says to keep using FM. Weather it's so the noise doesn't come back, or if there's a material property I don't know.

But you know me, I always try to get the best for my Z

I know how you are with your Z. The reason I want to use SAF-XJ is I like to change my diff oil. It is almost 20k since last changed. It's been running fine without +FM. Looks like I cannot upgrade my gears until end of year with the GBs. Need to reserve for Ohlin :-) I will use the good stuff after I upgrade my gears.

[beta]

Originally Posted by RobMCoupe

I know how you are with your Z. The reason I want to use SAF-XJ is I like to change my diff oil. It is almost 20k since last changed. It's been running fine without +FM. Looks like I cannot upgrade my gears until end of year with the GBs. Need to reserve for Ohlin :-) I will use the good stuff after I upgrade my gears.

That makes perfect sense. It seems that if you don't have noise you really don't need the extra expense of the booster.

Lots of good group buys this year, the bay area people are going to represent. All we need is an Airbox now

[RobMCoupe]

I decided to try Liqui Moly Synthetic Gear Oil (75W-140). This new product was designed specifically for BMW LS.

[KDiggityDog76]

How important is it that the diff and tranny drain bolt hex keys be short/stubby? I've got some Craftsman ones to fit my torque wrenches but they weren't listed as stubby in their item descriptions, per se. Is it really tight to get a tool in there on either the diff or tranny? I ask so I can have the correct tools handy before getting into this too deep. Always sucks to have to clean up to go to the hardware store at the outset of a job. Thanks guys!

[RobMCoupe]

Originally Posted by KDiggityDog76

How important is it that the diff and tranny drain bolt hex keys be short/stubby? I've got some Craftsman ones to fit my torque wrenches but they weren't listed as stubby in their item descriptions, per se. Is it really tight to get a tool in there on either the diff or tranny? I ask so I can have the correct tools handy before getting into this too deep. Always sucks to have to clean up to go to the hardware store at the outset of a job. Thanks guys!

Fill plug is pretty tight. I stripped the new plug because it hex bit was not in completely. A stubby hex is the way to go. I'll buy one before next change. I would get a extra set of plugs just in case.