SMG II gear change problems

[The Gorilla]

Hi,

For sure you can purchase parts.

Its like all these things, its finding
somebody that knows what there doing
and how to do it.

Look what work the OP has already
undertaken, some of it un-related for sure,
but the issue still exists.

Just wait to the new wave of Twin Turbo
Motors and their electronic Injection systems
and DCT Gearboxes start to play up, then the fun
and costs will really start big time.

Regards,

The Gorilla.

[Bounce]

Could it be as simple as the gear position sensor on the back of the gear box,Elms changed mine when I had a new pump fitted.

[shimmy]

Could it be as simple as the gear position sensor on the back of the gear box,Elms changed mine when I had a new pump fitted.

Just stick to bricks and concrete Brett :thumbs:

[Bounce]

Just stick to bricks and concrete Brett :thumbs:

I know fook all about those either:hahaha:

[shane@mbtech]

Sorry to be a vulture, but we have an smg box here if you need one.

[NZ_M3]

What software was used to reset the SMG system?

I've tried quite a few of them and in my opinion only the GT1 and ISTA works - the rest are rubbish (even INPA with its automated reset function).

If not done correctly and not done in the correct order it simply won't operate properly.

Here's the correct order for the reset:

1. Teach in clutch characteristic curve
2. adapt transmission fully
3. teach in clutch slip point
4. offset longitudinal sensor reset
5. Reset clutch values (under the GT1 this is under a different function within the menu - this is NOT under the standard SMG service menu, it is elsewhere).

My experience is if you don't do #5 above, there's really little point in doing 1 to 4 - as it simply means the system values are still operated against the 'old' clutch adaptation values (i.e. the compensating values stored long term) - so it'll still drive like arse.

when I get sometime I'll post up where to find this adaptation reset (I can't remember it off the top of my head right now).

Also when the SMG pump fluid was changed, was it bled properly with the proper tool?? See below for all the functions:

https://nam3forum.com/forums/forum/csl-register/general/csl-technical-area/513727-smg-service-function-screen-shots-in-bmw-gt1

For clutch test:

https://nam3forum.com/forums/forum/csl-register/general/csl-technical-area/515736-how-to-test-clutch-condition-with-the-gt1

Otherwise as Bounce stated, could be as simple as the gear positioning sensor (although being a 2nd to 3rd gear thing only, it seems unlikely, as that would mean 4th to 5th would be doing the same thing). The sensor itself houses two sensors within, one does the selection angle and the other shift travel - seems weired it is only doing it on 2nd to 3rd if it is sensor related.

[Mark CSL]

What software was used to reset the SMG system?

I've tried quite a few of them and in my opinion only the GT1 and ISTA works - the rest are rubbish (even INPA with its automated reset function).

If not done correctly and not done in the correct order it simply won't operate properly.

Here's the correct order for the reset:

1. Teach in clutch characteristic curve
2. adapt transmission fully
3. teach in clutch slip point
4. offset longitudinal sensor reset
5. Reset clutch values (under the GT1 this is under a different function within the menu - this is NOT under the standard SMG service menu, it is elsewhere).

My experience is if you don't do #5 above, there's really little point in doing 1 to 4 - as it simply means the system values are still operated against the 'old' clutch adaptation values (i.e. the compensating values stored long term) - so it'll still drive like arse.

when I get sometime I'll post up where to find this adaptation reset (I can't remember it off the top of my head right now).

Also when the SMG pump fluid was changed, was it bled properly with the proper tool?? See below for all the functions:

https://nam3forum.com/forums/forum/csl-register/general/csl-technical-area/513727-smg-service-function-screen-shots-in-bmw-gt1

For clutch test:

https://nam3forum.com/forums/forum/csl-register/general/csl-technical-area/515736-how-to-test-clutch-condition-with-the-gt1

Otherwise as Bounce stated, could be as simple as the gear positioning sensor (although being a 2nd to 3rd gear thing only, it seems unlikely, as that would mean 4th to 5th would be doing the same thing). The sensor itself houses two sensors within, one does the selection angle and the other shift travel - seems weired it is only doing it on 2nd to 3rd if it is sensor related.

Great Reply Tom i was just about to add this myself :bigcry:

[NZ_M3]

#5 Reset Clutch Curve - under control unit functions - SMG (second icon on the bottom right) - available after you've done a scan of the full system

[mooriginal]

Could it be as simple as the gear position sensor on the back of the gear box,Elms changed mine when I had a new pump fitted.

Thanks for that
considered that option but I dont have the symptoms of gear selection issues which i believe are with flashing gear selection in most gears

And have no problems from cold or around 1 -2

unless anyone else thinks im wrong about that ?

[mooriginal]

Thank you so much for the post - all of it helps
The garage are trying their best -

They use a specialist for the adaptations - but wasnt aware what method he use
I will confirm of course...

What software was used to reset the SMG system?

I've tried quite a few of them and in my opinion only the GT1 and ISTA works - the rest are rubbish (even INPA with its automated reset function).

If not done correctly and not done in the correct order it simply won't operate properly.

Here's the correct order for the reset:

1. Teach in clutch characteristic curve
2. adapt transmission fully
3. teach in clutch slip point
4. offset longitudinal sensor reset
5. Reset clutch values (under the GT1 this is under a different function within the menu - this is NOT under the standard SMG service menu, it is elsewhere).

My experience is if you don't do #5 above, there's really little point in doing 1 to 4 - as it simply means the system values are still operated against the 'old' clutch adaptation values (i.e. the compensating values stored long term) - so it'll still drive like arse.

when I get sometime I'll post up where to find this adaptation reset (I can't remember it off the top of my head right now).

Also when the SMG pump fluid was changed, was it bled properly with the proper tool?? See below for all the functions:

https://nam3forum.com/forums/forum/csl-register/general/csl-technical-area/513727-smg-service-function-screen-shots-in-bmw-gt1

For clutch test:

https://nam3forum.com/forums/forum/csl-register/general/csl-technical-area/515736-how-to-test-clutch-condition-with-the-gt1

Otherwise as Bounce stated, could be as simple as the gear positioning sensor (although being a 2nd to 3rd gear thing only, it seems unlikely, as that would mean 4th to 5th would be doing the same thing). The sensor itself houses two sensors within, one does the selection angle and the other shift travel - seems weired it is only doing it on 2nd to 3rd if it is sensor related.

[mooriginal]

Just as another points

does anyone think it might be relatively simple issue of syncro gear being worn out ?

[NZ_M3]

Just as another points

does anyone think it might be relatively simple issue of syncro gear being worn out ?

Very likely if it is isolated to 2- 3

3rd gear syncro ring are notoriously weak.

[mooriginal]

Thanks all for the posts on this thread

This weekend I went back to garage and sat and watched the adaptations done.
Double checked they were done in the correct order.

All steps completed with no warnings or errors.

Unfortunately the problem has still not gone away.

I didnt leave the car there as not sure what to do next - as didnt want to just let them talk it all of again just to check mechanicals


What we have found though is the following.

If on full power I change from 2nd - 3rd
where the problem lies -
If I lift of for a fraction during the change - and then plant the foot back down straight away the gear engages with out the clanking

It seems this method of treating it like a manual - seems to force the gear in without issues

I havent mastered it yet - as quite often i dont life appropiately
But it when it works it does work

Im teaching myself to drive around the problem.
The issue cannot be driven around if changing down gears if you want a busrt of power from lower gear of course...

Im not sure what to do other than give it to another garage who might have a different opinion or idea...

[giraffe]

Very likely if it is isolated to 2- 3

3rd gear syncro ring are notoriously weak.

Agreed , sorry good second hand box cheapest option .