Technical Speedo not working.

[Jayen4]

Hey all ! .....

Does anyone know how the speedo is driven on a '06 Doblo 1.9 , please ?? Is it from a mechanical or electronic unit on the gearbox or is it driven from a wheel sensor ? Anyone with specific knowledge on this please ?? Need to get it sorted....

 

[bugsymike]

Hey all ! .....

Does anyone know how the speedo is driven on a '06 Doblo 1.9 , please ?? Is it from a mechanical or electronic unit on the gearbox or is it driven from a wheel sensor ? Anyone with specific knowledge on this please ?? Need to get it sorted....

I think you will find it is from a electrical unit in the same place on the top of gearbox diff assembly area. Black plastic unit left front of this photo.

 

[Jayen4]

I think you will find it is from a electrical unit in the same place on the top of gearbox diff assembly area. Black plastic unit left front of this photo.

Thanks for that Bugsy..... I shall have a look . I'm not sure whether it's this unit or a broken wire , as I've just found broken wiring elsewhere on the car ( that controls other things ). .... Just as an aside...would the 'sender' unit be unique to the Doblo or could it be found on such as a Punto with the same engine ??

 

[bugsymike]

Thanks for that Bugsy..... I shall have a look . I'm not sure whether it's this unit or a broken wire , as I've just found broken wiring elsewhere on the car ( that controls other things ). .... Just as an aside...would the 'sender' unit be unique to the Doblo or could it be found on such as a Punto with the same engine ??

I would only be guessing, but assuming similar age 1.9 engine hopefully.
A lot of people on here swear by ePer details to identify parts so might be worth checking there.

 

[Jayen4]

Ok Update on this issue...... Today my local mechanic took out the the small electrical plug unit ( the one that Bugsy showed in the pic above ) and tried to test it for continuity.....couldn't get any readings from it . ( Apparently it should show either 12v or 5v , but getting nothing . ) . Have ordered a new one from the local factors . .... The other more concerning thing is that he thinks that the plastic drive gear , just inside the gearbox casing is worn out or chewed up ! Can that specific part be changed out / replaced , without having to remove and strip the gearbox ?? ....... Alternatively , does anyone on here have a suitable gearbox ( M88) to sell or even maybe a broken gearbox , that might have the speedo drive parts that I could use ??

 

[bugsymike]

Ok Update on this issue...... Today my local mechanic took out the the small electrical plug unit ( the one that Bugsy showed in the pic above ) and tried to test it for continuity.....couldn't get any readings from it . ( Apparently it should show either 12v or 5v , but getting nothing . ) . Have ordered a new one from the local factors . .... The other more concerning thing is that he thinks that the plastic drive gear , just inside the gearbox casing is worn out or chewed up ! Can that specific part be changed out / replaced , without having to remove and strip the gearbox ?? ....... Alternatively , does anyone on here have a suitable gearbox ( M88) to sell or even maybe a broken gearbox , that might have the speedo drive parts that I could use ??

That might be more of an issue if the problem is the drive on the diff gear assembly, normally they do not give a problem as nylon gears driving a very light load of the speedo sensor.
So unless speedo drive was forced in wrong in the past at an angle causing damage, in my mind the only other cause can be wear in the diff gear bearings causing slop so the plastic gears don't mesh properly.
I seem to recall early FWD Ford Escorts had a problem with that as they got older.

 

[Jayen4]

That might be more of an issue if the problem is the drive on the diff gear assembly, normally they do not give a problem as nylon gears driving a very light load of the speedo sensor.
So unless speedo drive was forced in wrong in the past at an angle causing damage, in my mind the only other cause can be wear in the diff gear bearings causing slop so the plastic gears don't mesh properly.
I seem to recall early FWD Ford Escorts had a problem with that as they got older.

Thanks for the reply !..... Hmmm..... I don't think that there's anything wrong with the diff gear bearings....Gearbox changes gears smoothly and no noises or vibrations from that department . I have ordered a new sensor plug/assembly....that is supposed to be here on tuesday , so I'll get that fitted and hopefully that will be the problem sorted . If that doesn't fix it , then I'm in trouble ! I will report back after I've got this sensor fitted .....

 

[bugsymike]

Thanks for the reply !..... Hmmm..... I don't think that there's anything wrong with the diff gear bearings....Gearbox changes gears smoothly and no noises or vibrations from that department . I have ordered a new sensor plug/assembly....that is supposed to be here on tuesday , so I'll get that fitted and hopefully that will be the problem sorted . If that doesn't fix it , then I'm in trouble ! I will report back after I've got this sensor fitted .....

The quick test is where the output drive shaft comes from the diff near the speedo drive , is see if excessive play up and down at that point.

 

[Jayen4]

The quick test is where the output drive shaft comes from the diff near the speedo drive , is see if excessive play up and down at that point.

I take it that you mean excessive play in the little shaft that connects to the sensor plug/assy ?? I shall check that before the new sensor unit is offered up..... Thanks for your help .

 

[bugsymike]

I take it that you mean excessive play in the little shaft that connects to the sensor plug/assy ?? I shall check that before the new sensor unit is offered up..... Thanks for your help .

No , I meant if you grab hold of the drive shaft where it enters the diff housing and shake it vigorously excessive movement in the diff bearings is bad..
Basically if the diff bearings are worn/loose then it means the nylon speedo drive gears don't mesh in lone and will wear out quickly, but really it is a sign of a more serious gearbox/diff problem, so hopefully not .

 

[Jayen4]

Aah

No , I meant if you grab hold of the drive shaft where it enters the diff housing and shake it vigorously excessive movement in the diff bearings is bad..
Basically if the diff bearings are worn/loose then it means the nylon speedo drive gears don't mesh in lone and will wear out quickly, but really it is a sign of a more serious gearbox/diff problem, so hopefully not .

Aah, I see...... I shall check that . Hopefully I don't end up needing a replacement 'box.... not good ! Thanks again .

 

[Jayen4]

No , I meant if you grab hold of the drive shaft where it enters the diff housing and shake it vigorously excessive movement in the diff bearings is bad..
Basically if the diff bearings are worn/loose then it means the nylon speedo drive gears don't mesh in lone and will wear out quickly, but really it is a sign of a more serious gearbox/diff problem, so hopefully not .

Update : So , fitted the new sender unit.... tested it with drill connected to drive shaft of the sensor and speedo works fine . .... Bad news is that there IS about 2mm of lift in the left side diff bearings..... and speedo does not work when all put back together . So it looks like a gearbox rebuild or replacement , which I can't afford at present ! If I didn't have bad luck etc .....

 

[bugsymike]

Update : So , fitted the new sender unit.... tested it with drill connected to drive shaft of the sensor and speedo works fine . .... Bad news is that there IS about 2mm of lift in the left side diff bearings..... and speedo does not work when all put back together . So it looks like a gearbox rebuild or replacement , which I can't afford at present ! If I didn't have bad luck etc .....

So similar issue to early front wheel drive Ford Escorts.
I was lucky with the 05 1.9 JTD Doblo some years ago to pick up a S/H gearbox for £80, so keep looking on eBay/Gumtree etc.
Alternatively a guy has just joined the Forum who rebuilds gearboxes @Fortunes Gate , maybe he can advise?

 

[Jayen4]

So similar issue to early front wheel drive Ford Escorts.
I was lucky with the 05 1.9 JTD Doblo some years ago to pick up a S/H gearbox for £80, so keep looking on eBay/Gumtree etc.
Alternatively a guy has just joined the Forum who rebuilds gearboxes @Fortunes Gate , maybe he can advise?

Thanks for that Mike..... I shall look up the 'new guy' ... A quick question on ePer..... Can parts be ordered directly from the ePer pages ? I called in at my local main dealers today and got them to look up availability and prices..... and the prices are outrageous , especially when compared to prices shown on ePer !! Also , the parts guy would not give me part numbers unless I actually ordered from them ! (ePer shows me part numbers anyway , so....) . Seems a bit dodgy to me !