SMG II gear change problems

[mooriginal]

Ok guys thought id post over here to see what you knowledgable peeps might think

Long story short.
I have a 2002 m3 Convert.
88K

I recently had the diff replaced as central bearing had issues and leaking seals too.
At the time I had terrible judder
and when they took out the clutch to replace it they found the clutch so badly worn that it was frayed at the edges

New clutch fitted

So work done.
1. Diff fitted
2. New clutch and flywheel
3. SMG fluid replacement for new
4. Diff oil - and friction modifer
5. SMG adaptations
6. New Salmon relay
7. 2x ident springs replaced
8. Pressure plate changed
9. Rubber flex disc replaced
10. Drivelogic left same as original settings
11. Rolling paddle reset done

Heres the problem

On full power - that is gunning it between
2nd into 3rd
3rd to 4th

I get a lag - the gear engages after a visible pause in power - and there is a sound from under the car - best described as a 'clacking' sound
like if you beat two pieces of two by four wood planks

There is a double 'clack' - and pause as car goes into gear between 2nd -3rd and 3rd - 4th.

All other gears are perfect and no problems, sounds etc.

Blipping on downshifts are fine

Downshifting into 3rd or 4th - does have a delay and car does not select the lower gear until its happy in the problem gears only.

In other gears the downshifting is fine...

Can anyone throw any suggestions

Someone mentioned to me syncromesh ?

Any thoughts appreciated.

Mo

[mooriginal]

Also does this make sense

When I had original juddering problem It started off between 2-3 3-4
This got worse and it started happening in all gears so quickly realised that the clutch needed replacing
However didn't get clutch replaced for about 2 months due to needing car as daily driver for work

So did the car store in memory the readings or problems with these gears that it then carried over to the new clutch ?

[Mark CSL]

Was the cluch bite reset ?
after the clutch was fitted

[mooriginal]

Was the cluch bite reset ?
after the clutch was fitted

Hi Mark

Im not sure - ive asked the owner of the garage to confirm...

[manos///3]

I had familiar issues.
Check output cylinder clutch Nr8 http://bmwfans.info/parts/catalog/E4...rol_m_gearbox/
Mine , the plastic on edge was quite dissolved.

[mooriginal]

I had familiar issues.
Check output cylinder clutch Nr8 http://bmwfans.info/parts/catalog/E4...rol_m_gearbox/
Mine , the plastic on edge was quite dissolved.

Thank you so much for that link
the car is due back in garage soon for them to check again

[mooriginal]

Was the cluch bite reset ?
after the clutch was fitted

Ive asked and the owner isnt sure it was done
he used a specialist to come in to do the adaptations etc who has all the Gt1 kit etc..

hes going to re-confirm

thank you will get it checked when the car is in

[Mark CSL]

Ive asked and the owner isnt sure it was done
he used a specialist to come in to do the adaptations etc who has all the Gt1 kit etc..

hes going to re-confirm

thank you will get it checked when the car is in

Bmw do this after they fit a new clutch to reset the bite
they can also run a check on the gearbox.

If i was you ask a bmw bealer for a price to run a check on the clutch and gearbox should only be about 1 hour labour :thumbs:

[mooriginal]

I had familiar issues.
Check output cylinder clutch Nr8 http://bmwfans.info/parts/catalog/E4...rol_m_gearbox/
Mine , the plastic on edge was quite dissolved.

Garage has confirmed now that the was checked and the mine was pointed and in good condition

[mooriginal]

Bmw do this after they fit a new clutch to reset the bite
they can also run a check on the gearbox.

If i was you ask a bmw bealer for a price to run a check on the clutch and gearbox should only be about 1 hour labour :thumbs:

Thanks

I shall get the garage to do it as its still their problem for now
I trust the garage as the owner has become a mate through these problems.
He wants to get into doing proper servicing on M cars so treats this as a learning experience ...

If all things fail ill take it to another specialist who is very well respected.. but I wanted to exhaust the possibilites first ..

I will defo ask if clutch biting point was reset
but this strikes me as an obvious thing to do with a new clutch
and would get missed if someone forgot to only...

[The Gorilla]

Hi,

Pure Guess on what your have descibed.

Your selectors in the Gearbox are worn,
and so when you engage, instead of the
detent Springs aligning for selection,
they are mis-aligning, solenoid actuators
clacking, so that there is
resistance at the selection take up.

Changing up under load, so I am guessing
that the 'clacking' noise is the selectors trying
to engage, actuators, hence why you have a delay in
Gear changes.

Changing down, the engine 'Brake' loads as you
change down which loads the drive train and hence
the selection process is again mis-aligned.

I would guess that if you drive hard, lift off,
so as to unload the drive train and select to
change up then it will be much smoother and
without hesitation as the 'selectors' are not
under load and so slide in easier.

Just my guess on what you have said.

Regards,

The Gorilla.

[mooriginal]

Hi,

Pure Guess on what your have descibed.

Your selectors in the Gearbox are worn,
and so when you engage, instead of the
detent Springs aligning for selection,
they are mis-aligning, solenoid actuators
clacking, so that there is
resistance at the selection take up.

Changing up under load, so I am guessing
that the 'clacking' noise is the selectors trying
to engage, actuators, hence why you have a delay in
Gear changes.

Changing down, the engine 'Brake' loads as you
change down which loads the drive train and hence
the selection process is again mis-aligned.

I would guess that if you drive hard, lift off,
so as to unload the drive train and select to
change up then it will be much smoother and
without hesitation as the 'selectors' are not
under load and so slide in easier.

Just my guess on what you have said.

Regards,

The Gorilla.

Thanks Gorilla

That makes sense with how ive been driving while this is happening
Im in s3 mode all the time now
and as I go through the gears im always careful to change up between 2nd to 3rd below 3k revs or with foot off the pedal and not too fast ...
This works every time ...

However today I was caught in front of car up my a$$
and booted it a bit around the roundabout
of course 1-2nd fine but forgot about 3rd

clack clack - clack - clack -clack
I was on so many revs that this time the gear seelctor just flashed at me
i changed up to 4th to try and catch a higher ratio - still flashing

finally id slowed down by now enough that I reselected 2nd which engaged and then went up the gears smoothly

sheesh !

Is there anyway to service the 'selectors'?

[The Gorilla]

Hi,

Find a replacement SMG Gearbox
in good condition with as low
mileage as poss, will be by far
the Cheapest option.

Regards,

The Gorilla.

[mooriginal]

Hi,

Find a replacement SMG Gearbox
in good condition with as low
mileage as poss, will be by far
the Cheapest option.

Regards,

The Gorilla.

:bigcry::bigcry::bigcry:

[plug]

Hi,

Find a replacement SMG Gearbox
in good condition with as low
mileage as poss, will be by far
the Cheapest option.

Regards,

The Gorilla.

Will BMW or Getrag not sell parts separately or something?