E9X Transmission hard to engage 1st when it's cold out

[veer90]

Update: Pentosin FFL3 was the correct fluid and fixed most of my issues.

6MT Spec 3+ SMFW. no CDV. When cold out (<40*) the transmission doesn't like to go into 1st without either:

• car slowly moving forward (if on smooth ground and no brakes, the car will actually roll forward with clutch fully depressed as I try to put it in 1st)
• engaging 2nd beforehand
• hamfisting it (significant force)

I read on N5x enthusiasts some guy supposedly had luck with putting a MoS2 additive in his MTF and it fixed this problem.

I have Amsoil MTF which is more viscous (9.7 cSt at 100C) than ZF specification for the gearbox, which I'm sure is not helping the problem. https://bmw.spoolstreet.com/threads/smfw-chatter.2110/#post-21962

Should I order additive, or new fluid? I've had Redline D4 before and didn't like it, shifts were notchy especially 3rd gear. Notchy shifts and the fact that I race the car (autox/drag/road course) is why I switched to a thicker fluid.

 

[Itsbrokeagain]

clutch is not disengaging correctly.

do you have a clutch stop? if so remove it. Did you use the OEM throwout bearing? Ive had several horror stories with trying to install Specs version of the TOB.

 

[veer90]

There's no evidence of the clutch not disengaging correctly, it shifts perfectly smooth and normally when warmed up and the RPMs drop instantly when I clutch in at speed. which is why I'm thinking it's thick fluid / 1st gear synchro not playing nice when it's cold.

I can double check with the shop which TOB they used.

 

[Itsbrokeagain]

how notchy was the transmission before you installed the clutch? Was it working perfectly fine?

 

[veer90]

The transmission has always worked fine, except for this recent issue. With the OEM MTF and Redline D4 it was a bit notchy going into all gears and most noticeable going into 3rd.

No "shift boot packed with ground glass" feeling, just not as smooth going into the gates.

 

[Itsbrokeagain]

i still think the clutch has something to do with it. Ive done a D4 flush in several trans and they shift like butter. But for it to get worse right after the clutch install leads me to believe something may be awry.

Did they change the pivot pin while it was out?

 

[veer90]

i still think the clutch has something to do with it. Ive done a D4 flush in several trans and they shift like butter. But for it to get worse right after the clutch install leads me to believe something may be awry.

Did they change the pivot pin while it was out?

Yes I have a brass pivot pin

Also I should clarify I've had this clutch for 14k miles now, installed 04/2017. Only started noticing this problem when the weather got colder.

 

[veer90]

Just ordered the ZF recommended fluid Pentosin FFL3, hopefully that fixes it

 

[veer90]

update: FFL3 in the gearbox fixed most of the issues. 1st can still be difficult sometimes when cold but is a lot better. also noticed I'm able to downshift into 1st at higher speeds (up to 15mph vs max 5mph with the thicker fluid).

 

[doublespaces]

How long does it continue to be clunky for in the cold?

 

[veer90]

How long does it continue to be clunky for in the cold?

It was never clunky in the cold, just hard to engage 1st gear.

Now instead of hamfisting it, all it needs is a little extra push to select 1st gear when the transmission is totally cold.