Selespeed 156 Advice Needed

[Mike2909]

After close to 6000 miles and 4 months of exhilarating,problem free selespeed driving my first problems are starting.
Any advice would be appreciated.
The problem started about 2 weeks ago. I was out for a drive one evening and was hammering her around the B roads out in the country. I was in 5th gear and wanted to drop down to 4th for an approaching bend. She would not go into gear and went into neutral although 5 was still showing on the display,I tried to drop another gear and nothing again, I went back up the box and she engaged 5th.I had to drop the revs and kept trying to change gear, I eventually got her into 2nd and kept her ticking over,I pulled over and changed into neutral and then 1 and pulled away.
She pulled through all the gears up to 5 and not a hitch. Trying to change down again she would not select 4, the gearbox was missing gears and going to 5th all the time. I drove home and then put her on Alfa diag but no selespeed errors were shown only a speed sensor error. We did a re calibration and all was back to normal working.
Oil level is at maximum and has been for the past 4 months, she does not use any sele oil. On Alfa diag clutch pin was perfect and pump pressures normal.
She drove normal for almost a week and then the same problem occurred. I was out for a drive and as soon as I started hitting the red zone s and she was fully warmed up the gear selection problem started again.
I have been advised it could be the clutch release bearing but would like and appreciate any input anybody has.
One more thing, is a fully operational Sele good for this kind of driving or am I better looking for a manual? I have been on 2 track days with her and when the gearbox is running as should she is a pleasure to drive.
I do not use the car for commuting (I cycle to work as it is only 5 miles away) and if I take Stella (the selespeed) she is never driven above 3500 revs as she does not reach optimum operating temperature by the time I reach work.
Stella is my hobby and I bought her just for the fun of driving but there is no fun waiting for problems to happen.
Thanks for any help.

[Mike2909]

Additional facts.
There is no noise from the gearbox when changing gears.
The clutch,actuator and gearbox were replaced 26K ago but there is no mention of the clutch release bearing on the invoice only "clutch kit" and I have been told this does not include the release bearing.
When the problem starts its always going from 3rd to 4th she will not select 4th gear and instead chooses 5th.When I try to change from 5th to 4th the display shows 5th but she is in neutral, if I drop the revs down she then accepts the 5th gear.
We have checked for swarf build up in the gearbox but as good as nothing in there.
When I got home I checked the gear selection with the key at mar and she went 1 2 3 5 and down 5 4 2 1.
This morning when she is cold with the key at mar gear selection is correct 1 2 3 4 5 5 4 3 2 1 and from 5 to R without a hesitation.
When I open the drivers door the pump primes as normal .

[iainfm]

Fault codes we've seen recently are listed below. However, there were no fault codes (engine or selespeed) logged after the last time it misbehaved...which would lead me to suspect something mechanical - like the release bearing.

P0725

Failed Component Code: Engine Speed
Fault Symptom: Signal Not Plausible
Warning Lamp Status: Warning Lamp Illuminated
Fault Test State: Test complete for this Error or not applicable.
Fault Code Storage State: Error Not Present at time of request
Event Count: 26 count
Environmental Condition One: Time Error Present: 255 minutes
Environmental Condition Two: Engine Speed : 0 rpm
Environmental Condition Three: Vehicle Speed: 7.05 km/h
Environmental Condition Four: Gearbox Oil Temp: 64 °C
Environmental Condition Five: Requested Gear: Second
Environmental Condition Five: Inserted Gear: Second
Environmental Condition Six: Battery Voltage: 12.59 volts

P1746

Failed Component Code: Switch Lever 1
Fault Symptom: Signal Not Plausible
Warning Lamp Status: Warning Lamp Illuminated
Fault Test State: Test complete for this Error or not applicable.
Fault Code Storage State: Error Not Present at time of request
Event Count: 57 count
Environmental Condition One: Time Error Present: 56 minutes
Environmental Condition Two: Engine Speed : 544 rpm
Environmental Condition Three: Vehicle Speed: 0 km/h
Environmental Condition Four: Gearbox Oil Temp: 57.6 °C
Environmental Condition Five: Requested Gear: Neutral
Environmental Condition Five: Inserted Gear: Neutral
Environmental Condition Six: Battery Voltage: 11.69 volts

P1747

Failed Component Code: Switch Lever 2
Fault Symptom: Signal Not Plausible
Warning Lamp Status: Warning Lamp Illuminated
Fault Test State: Test complete for this Error or not applicable.
Fault Code Storage State: Error Not Present at time of request
Event Count: 57 count
Environmental Condition One: Time Error Present: 56 minutes
Environmental Condition Two: Engine Speed : 544 rpm
Environmental Condition Three: Vehicle Speed: 0 km/h
Environmental Condition Four: Gearbox Oil Temp: 57.6 °C
Environmental Condition Five: Requested Gear: Neutral
Environmental Condition Five: Inserted Gear: Neutral
Environmental Condition Six: Battery Voltage: 11.69 volts

P1762

Failed Component Code: CAN message transmission
Fault Symptom: No Signal
Warning Lamp Status: Warning Lamp Illuminated
Fault Test State: Test complete for this Error or not applicable.
Fault Code Storage State: Error Not Present at time of request
Event Count: 11 count
Environmental Condition One: Time Error Present: 255 minutes
Environmental Condition Two: Engine Speed : 0 rpm
Environmental Condition Three: Vehicle Speed: 0 km/h
Environmental Condition Four: Gearbox Oil Temp: 28.8 °C
Environmental Condition Five: Requested Gear: Second
Environmental Condition Five: Inserted Gear: Second
Environmental Condition Six: Battery Voltage: 12.59 volts

[rarebear]

did you do a check with Alfadiag on the clutch rod lenght ? (should be 28 28.5 mm) pressure ? 50 bar

and a re-calibrate ?

but the release bearing is suspect as well (mine went after 110k kilometres)

[Mike2909]

Originally Posted by rarebear

did you do a check with Alfadiag on the clutch rod lenght ? (should be 28 28.5 mm) pressure ? 50 bar

and a re-calibrate ?

but the release bearing is suspect as well (mine went after 110k kilometres)

Clutch rod length was adjusted and set to 28.3mm 3 months ago and is still at this setting now.
The pressure was correct . We have re calibrated twice and both calibrations were successful. The car then runs normally again until I go out for a "drive"

[rarebear]

trashing a selespeed is not really advisable, even Porsches and BMW M3's with simular systems destroy
their clutches in a short time ! they even have a programming fix that prevents multiple crash starts !

[iainfm]

Zero fault codes reported again today...

[Smaky]

Disconnect and clean all the selespeed plug connectors, I suspect that there is a bit of oil in one of them and this is brwaking the circuit, most likely the speed sensor plug on the front of the gearbox.

[iainfm]

We took it for a spin today with AlfaDiag hooked up. All T's and P's looked fine, but it was (fairly regularly) not selecting 4th going up, or 3rd coming down.

I plotted the sensors for requested gear and inserted gear, which was interesting. In normal operation, a gear change would be registered in the 'requested gear' sensor, shortly followed by the 'inserted gear' sensor as the change was made.

However, when the system was 'playing up', it was a different story. While running in 3rd and changing up, the requested gear would change to 4th, followed by no drive/insertion. The requested gear would then change automatically to 5th, followed by the actual insertion.

Coming down from 4th to 3rd would show the requested gear as 3rd, followed by no drive. Then the requested gear changed automatically to 4th (with no drive), then automatically changed to 5th, shortly followed by a good insertion.

What I didn't try was plotting the vehicle speed sensor, which might have shown something up. We'll have another look at the connections as well...

[iainfm]

Been out for another test drive. It's now consistently failing to insert gears, like this going up:

1-2-3-F-5

and down

5-4-F-5

(where F is a failed change, and the number after it is the gear that results).

However, fooling the box by doing a double up change from 3rd to 5th, then back to 4th works fine.

We checked the vehicle speed and engine speed sensors, and they're reading fine without any glitches whatsoever. Circuit pressure is typically 50 bar, never less than 45, never more than 55.

I've also graphed the position of the insertion fork, and it would seem to suggest that on failed changes the position is only going as far as the neutral position, before going back to its previous position.

I've attached a picture showing what we've seen. I can begin to correlate it to a manual gate now. It's like the forward/backward or left/right motion of the 'gearstick' isn't quite right for some reason...

All suggestions welcome!

Cheers,

Iain

[Smaky]

You have a failed 4th gear synchro, the sele is working fine,time to open the box up and replace those rings.

[Mike2909]

You have a failed 4th gear synchro, the sele is working fine,time to open the box up and replace those rings.

Why does it go into 4th if i trick it and when coming down the box normally? I accept what you say I am just trying to understand it.
When its working the gears are as smooth as silk.

[iainfm]

Originally Posted by Smaky

You have a failed 4th gear synchro, the sele is working fine,time to open the box up and replace those rings.

Even though there's no crunchy noises? It was something on my list of things-it-could-be, but didn't-want-it-to-be

You got a how-to?

Edit: Or part numbers?

[argtv6]

Originally Posted by Smaky

You have a failed 4th gear synchro, the sele is working fine,time to open the box up and replace those rings.

Wouldn't 4th grate?
It hasn't been mentioned.
I think it is more likely the selespeed harness connector sitting above the gearbox-next to the battery. Give it a dose of contact cleaner or better still-eliminate it and solder up the wires.

[iainfm]

Wouldn't electrical faults be logged in the ECU?

[argtv6]

Alfa have a modification for the same notorious multi-connector, with connectors of better material and current carrying capabilities. It involves a myriad of part numbers and extreme patience to get the job done.
The soldering is easier with better results.

[iainfm]

We're going to re-double-check the electrics tomorrow (weather permitting). Does soldering the wires together affect the ability to remove anything (eg the actuator)?

Soldering iron at the ready

Cheers,

Iain

[argtv6]

To remove the actuator with soldered wires, one has remove the harness from the individual solenoids and sensors on the unit. Nothing too hard with the battery tray removed and marking all the positions.
Before soldering, see if the contact cleaner improves things somewhat. Some repairers even twist each individual male slider in the multi-connector to make the connection tighter. IMO this results in a smaller contact surface area which will eventually give rise to problems in the future.

[Smaky]

If the 3rd to 4th synchro has lost its teeth then when the car is at the optimum engine and road speed it would still select 4th, if you are thrashing itthen the car will not select it and go to the next highest gear (which iti is doing) to this end the electronics of the sele are fine as is the actuator, so either the speed sensor (no code though) or the synchro has gone and to be sure I'd also replace the 4th cog too.

If you have a CF2 then the 4th ratio is 32/37 so these are the items...hows your box rebuilding skills?

Synchro - 46545896

4th - 46767061

[Mike2909]

Originally Posted by Smaky

If the 3rd to 4th synchro has lost its teeth then when the car is at the optimum engine and road speed it would still select 4th, if you are thrashing itthen the car will not select it and go to the next highest gear (which iti is doing) to this end the electronics of the sele are fine as is the actuator, so either the speed sensor (no code though) or the synchro has gone and to be sure I'd also replace the 4th cog too.

If you have a CF2 then the 4th ratio is 32/37 so these are the items...hows your box rebuilding skills?

Synchro - 46545896

4th - 46767061

The problem did start when I had been thrashing her.After we had re-calibrated she worked as normal again for close to two weeks including a few evenings hard driving. The problem then re appeared after an evening session. I left her overnight and then using her for work ( never above 3500 as she is cold) she changed normally going to work but on the way home almost at the end of the journey ( 5 miles) she missed 4th again.. I went down to my Mclaren technician (iainfm) and on Alfa diag there were zero fault codes although the first couple of times the problem occurred there was a speed sensor fault code.

If it is the synchro is there a reason it has gone as this gearbox has done less than 30k miles? and part 2 of my original question am I better with a manual gearbox which would be a pain as I really enjoy driving the sele.

[argtv6]

By 're-calibrated', do you mean the EOL(end of line) routine?
If not, perform this procedure with alfadiag as it essential to show that there are no major faults present.

[Mike2909]

Yes the EOL routine was performed and successfully. But we were told that performing this routine can damage the gearbox so not to perform it when not necessary.

[David156]

A change of gear oil may help to some degree, it may even effect a cure if there is a lot of 'swarf' in it.
Must be worth a try??

[Mike2909]

Originally Posted by David156

A change of gear oil may help to some degree, it may even effect a cure if there is a lot of 'swarf' in it.
Must be worth a try??

The gear oil was changed less than 1000 miles ago and we checked the gearbox for swarf last week and there was as good as nothing in there.

[iainfm]

Originally Posted by Smaky

If the 3rd to 4th synchro has lost its teeth then when the car is at the optimum engine and road speed it would still select 4th, if you are thrashing itthen the car will not select it and go to the next highest gear (which iti is doing) to this end the electronics of the sele are fine as is the actuator, so either the speed sensor (no code though) or the synchro has gone and to be sure I'd also replace the 4th cog too.

I forgot to say last night that the changes were failing even with the car stationary, which is new and presumably just indicates that the problem is getting worse.

Originally Posted by Smaky

If you have a CF2 then the 4th ratio is 32/37 so these are the items...hows your box rebuilding skills?

Synchro - 46545896

4th - 46767061

Thanks. The last gearbox I rebuilt was from a 50cc dirt bike when I was about 12 . I stripped my v6 cavalier's F25 box when it failed, but only for interest's sake and with no intention of putting it back together!

I have a couple of CF2 manual boxes waiting for something to happen to them. Could they be used for donor parts (eg swap the bell housing and casing over)? Or is that false economy and/or impossible?

Cheers,

Iain