SMG Problems

[beyondm3]

Just realized the error I posted wasn't translated for when I attempted to do the adaptation. Below is the translation.

SMG2-installation procedure for rework V1.01 BMW TI-430 Gall
SMG2-installation procedure
Vehicle with VIN: not readable
start diagnostics read engine speed: 0
adapt longitudinal acceleration sensor test status: Test program ended info status: No error
adapt clutch valve test status : Test program not ended properly info status: Engaging position outside the permissible tolerance
break at: adapt clutch valve

[oceansize]

There are two values within INPA for SMG adaptations that I think relate to your failure. The clutch disengagement position (auskuppelstellung) and the clutch bite position. Since your error relates to "engagement" that is for clutch bite. Clutch bite range is from 640 to 1020 and mine is at 830. It looks as though yours is currently outside that permissible range.

To me, it sounds like your clutch slave cylinder has gone bad which would correlate to the earlier error 59 that you received. Can I be 100% sure? I cannot. But if it was me I would replace the clutch slave and go from there, but up to you obviously.

[beyondm3]

That's exactly what I was just thinking as well. Unfortunately I was also thinking that a slave cylinder is typically sub $100.... I should have known better for SMG. I'll start shopping around.

[beyondm3]

There are two values within INPA for SMG adaptations that I think relate to your failure. The clutch disengagement position (auskuppelstellung) and the clutch bite position. Since your error relates to "engagement" that is for clutch bite. Clutch bite range is from 640 to 1020 and mine is at 830. It looks as though yours is currently outside that permissible range.

To me, it sounds like your clutch slave cylinder has gone bad which would correlate to the earlier error 59 that you received. Can I be 100% sure? I cannot. But if it was me I would replace the clutch slave and go from there, but up to you obviously.

Are these worth rebuilding?

[oceansize]

Are these worth rebuilding?

Mine went out at 100,000 miles and I simply bought a brand new one. The piston on the new clutch slave doesn't move. It has a one time use clip that breaks, after you install it, the first time it is used. That clip aids in lining up the clutch slave piston rod and the dimple on the plate it rests against during installation. If it wasn't for that clip holding the rod in place it gets much tougher to line up the dimple and the rod. It can be done, just harder to do.

This company, who I have bought parts from, has a variety of options from the new OEM unit to just the seals.

https://mlreng.com/products/smg-ii-c...32496797089879

[Good]

I think it's pretty obvious that once hydraulic fluid is at operating temperature you are suffering internal and/or external leaking. Rebuild your SMG pump, forget replacing fuses, relays, sensors. Relocating your pump after rebuilding your unit may help with longevity, but at the end of a day, seals don't last 15+ years.



I put together a DIY a while ago on the old M3f and I will post another rebuild DIY.

[oceansize]

I put together a DIY a while ago on the old M3f and I will post another rebuild DIY.

What did you torque the bolts that seal the three pump plates together to (where the gears reside)? I'm always curious to hear what torque value others went with as I could never find this documented when I was doing my rebuild.

[sapote]

Original accumulator but all new seals and o-rings.

Unbelievable well made accumulator using piston and seals!! My Citroen SM has 6 total accumulators (actually one main system accumulator, one for brake system, and 4 corners suspension spheres but they are all made the same) using a dense rubber membrane as the divider between Nitrogen gas and hydraulic oil, and the Nitrogen molecules eventually diffused through the membrane and then they need to be charged every 3 to 4 years.

[sapote]

This company, who I have bought parts from, has a variety of options from the new OEM unit to just the seals.
https://mlreng.com/products/smg-ii-c...32496797089879

From their website:
"Vehicles over 100k miles and performing clutch change should replace clutch slave or rebuild withour sealkit. Over time internal seal will crack and it becomes difficult for SMG pump to controll clutch position, this causes extra stress on pump components and eventually lead to pump failure or error codes associated with clutch control.
This unit has two internal seals and will leak internally so you will not notice the problem externally."

This statement sounds as if the slave cylinder leaks inside then the pump has to run more often to maintain the pressure. But since there is only one hydraulic pipe (no return pipe) connected to the slave, then where is the leaked oil inside the slave going to if not dropping on the floor?

$75 is a very good price with the position encoder.

[oceansize]

From their website:
"Vehicles over 100k miles and performing clutch change should replace clutch slave or rebuild withour sealkit. Over time internal seal will crack and it becomes difficult for SMG pump to controll clutch position, this causes extra stress on pump components and eventually lead to pump failure or error codes associated with clutch control.
This unit has two internal seals and will leak internally so you will not notice the problem externally."

This statement sounds as if the slave cylinder leaks inside then the pump has to run more often to maintain the pressure. But since there is only one hydraulic pipe (no return pipe) connected to the slave, then where is the leaked oil inside the slave going to if not dropping on the floor?

That is a good question and I can't answer. I probably should have disassembled my old one.

[Good]

SMG Pump Rebuild DIY: https://nam3forum.com/forums/forum/m...mp-rebuild-diy

What did you torque the bolts that seal the three pump plates together to (where the gears reside)? I'm always curious to hear what torque value others went with as I could never find this documented when I was doing my rebuild.

Finger tight. You need the gears to be able to rotate without pressure.

[sapote]

SMG Pump Rebuild DIY: https://nam3forum.com/forums/forum/m...mp-rebuild-diy



Finger tight. You need the gears to be able to rotate without pressure.

Then how to prevent the bolts from backing out?

[beyondm3]

Looks like bleeding the pump and clutch seems to have resolved any restart issues I had. I was able to restart the vehicle at temperatures above what I had previously recorded from INPA when in a "no start" state.

I do have a question about the relocation kit. Despite it being hard to find a bracket, my drug bin contains the abs/dsc module. I saw in the earlier post that it looks like it was moved or relocated, is this a 2002.5 change or not? And is it possible to fit both units in there if I find a bracket?

[robgill]

Good to see you got is resolved. If you have an early car with the DSC module in the drug bin the SMG relo will not fit. I use the BE bracket on my 2003 and it’s a tight fit!

[Darbshaw]

Looks like bleeding the pump and clutch seems to have resolved any restart issues I had. I was able to restart the vehicle at temperatures above what I had previously recorded from INPA when in a "no start" state.

I do have a question about the relocation kit. Despite it being hard to find a bracket, my drug bin contains the abs/dsc module. I saw in the earlier post that it looks like it was moved or relocated, is this a 2002.5 change or not? And is it possible to fit both units in there if I find a bracket?

So this fella here managed to make his own bracket and res setup back in the day. This was the inspiration for me doing my setup. Saved quite a bit of money using my own bracket.
Although his shows that it is possible to mount the pump with the dsc module inside the drug bin.
Link here: https://www.bmw-syndikat.de/bmwsyndi...ml?pagebreak=8

My setup as well. Cost me about $20 in aluminum plate to do this mount. I want to eventually give it a little more fit and polish but it’s functional for now.


I hope some of this can help you get it done! If you can make you’re own bracket setup it will save you a good chunk of change for the relocation.


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