Technical Dualogic issue after gearbox change

[Noendo]

Hi, I've spent hours online mainly on the fiatforum trying to find anyone who's had a similar issue to me but I can't so if someone can help please.

My 1.4 16v dualogic 500 needed a new gearbox due to a diff issue and rather than start messing with diffs a low milage replacement gearbox was sourced on the bay that also had the dualogic robot attached. The dualogic robot on my car was working fine before so I transferred it onto the replacement box and fitted it back into the car.

My issue now is it stutters when changing mainly from 3rd gear upwards, the dash tells me it's changed gear then after around 1 second the revs drop and I loose power only to have it jerk into gear. After around 30 mins of driving I get a message on the dash that the clutch is overheating. Once it's in gear it's fine but the issue is changing gear.

I've gone through the calibration process using Alfaobd and all operations finish without failing and I can hear the gearbox running through the gears.

Has anyone experienced this before or am I missing out a crucial step that can fix the issue.

Thanks for reading

 

[portland_bill]

Have you calibrated the clutch operation as well as the gearchange?

 

[Noendo]

I followed the instructions as follows

the first operation “statistical data deletion”: is to be performed once;
the second operation “clutch self-calibration enable” is to be performed twice;
the third operation “service self-calibration” is to be performed three times

 

[Noendo]

From further reading the term 'clutch dragging' seems to sum up the issue, I'm now thinking the clutch fork could be bent but would the software procedures complete without failing?? My next move was going to be cleaning all the connectors as it could still be an electrical fault not a mechanical one.

 

[John202020]

I would say "clutch overheating" is exactly that check this first?

 

[Noendo]

One thing that I never swapped over was the speed sensor in the gearbox, the replacement box was from a 1.2 8v. Shop4parts list one for a 1.2 8v but not for the 1.4 16v so could this be causing the issue?

 

[puntodeltathema]

Was the 1.4 dualogic a five speeder? If not, presume you know that the 1.2 was only 5 speeds? Are the robots the same?

 

[Noendo]

Yeah both 5 speed boxes. Well the speed sensor swap didn't make any difference, I am getting a fault code now which is P2912 so I'll look into that next

 

[portland_bill]

Fitting a 1.2 box as a replacement for the 1.4 box, could work, or might bring issues.
Whilst the casing may look the same, details like input shaft length, depth of bell housing, distance from clutch fork pivot to clutch cover, etc., may have small but significant differences. If the 1.4 flywheel is a different thickness to the 1.2, that changes the distance of the clutch from the gearbox, and release bearing. Might all be the same. Was any, or all of this checked prior to fitment?

EDIT: Since writing the above, I have managed to research using ePER. Bell housing, clutch, and selespeed control units are same for 1.2 and 1.4. So the replacement box should not throw up issues with operation, although gear ratios might be different.

Possible, replacement box has issues too.

 

[Noendo]

A couple of sources indicate it's the same box but I can't be 100%.

I'm going to remove the replacement gearbox, see if anything is obviously wrong and check if it's the same box then decide if I'm going to reinstall with a new clutch or repair the original box that on closer inspection only needs the diff bearings replaced.

I'd like to check eper for cross-referencing part numbers but it doesn't list the 500??

 

[Noendo]

Fitting a 1.2 box as a replacement for the 1.4 box, could work, or might bring issues.
Whilst the casing may look the same, details like input shaft length, depth of bell housing, distance from clutch fork pivot to clutch cover, etc., may have small but significant differences. If the 1.4 flywheel is a different thickness to the 1.2, that changes the distance of the clutch from the gearbox, and release bearing. Might all be the same. Was any, or all of this checked prior to fitment?

EDIT: Since writing the above, I have managed to research using ePER. Bell housing, clutch, and selespeed control units are same for 1.2 and 1.4. So the replacement box should not throw up issues with operation, although gear ratios might be different.

Possible, replacement box has issues too.

Thanks! I appreciate you taking the time to check

 

[mj2k]

Just been thinking about your issue, sounds like a very (clutch) slippery situation!

Have you still got the original box? If so is there any chance you can swap the diffs between boxes and refit the original to eliminate software or robot incompatibility as the cause of the issue? Or swap to the 2nd hand robot so you can at least eliminate that from your enquiries?

 

[portland_bill]

Just been thinking about your issue, sounds like a very (clutch) slippery situation!

Have you still got the original box? If so is there any chance you can swap the diffs between boxes and refit the original to eliminate software or robot incompatibility as the cause of the issue? Or swap to the 2nd hand robot so you can at least eliminate that from your enquiries?

If swapping the diff, make absolutely sure the pinion on the mainshaft is the same as the original. If final drive is different, likely both parts, pinion and crownwheel are also different.
If the old bearings are just worn, new ones should fix the issue, but will need reshimming, don't just refit the original shims and hope. If the old bearings have shed any debris, make sure the whole gearbox is clean inside.

 

[Noendo]

Today I took the dualogic robot off can found one of the two tabs bent inwards so this could of been causing the issue. Anyway I've now replaced the diff bearings on the old box, heated and bent back the tab and installed it all back into the car. It now changes gear beautifully after the carrying out all the software procedures.

Thanks for everyone's help

 

[mj2k]

10/10 for perseverance, that frustrating issue would have had many people reaching for the Autotrader...

 

[A3jeroen]

Well done!
That looks badly bent. Did this happen during transport?

gr J

 

[Noendo]

10/10 for perseverance, that frustrating issue would have had many people reaching for the Autotrader...

I wouldn't of taken it apart for a 3rd time believe me! It's been a great little car and easy to work on so I was reluctant to give up especially after doing a few major jobs on it recently

 

[Noendo]

Well done!
That looks badly bent. Did this happen during transport?

gr J

I didn't see it being like that when I installed it onto the replacement box only when taking it off, who knows