Technical Fiat 500 semi automatic gearbox

[bestmotors]

Hello good people.
Basically we own a Fiat 500c on 40k miles 2015.
This car we purchased was juddering and jumping and jerking in nearly all gears, worst in reverse. Took the gearbox off to see that there was oil contamination on the clutch, we sent the gearbox to get repairs/sills and changed over the clutch, seen that the selespeed oil was slightly low, topped that up and did all the calibrations and learnings.
However the vehicle is exactly the same.
Having so many voices for 10 different steps to take, change the selespeed unit, change the flywheel, etc etc.
All which cost to do, im literally stuck.
Anyone with experience point me in the right direction?

 

[GettinBetter]

I would suggest you start here
It's a heavy topic, but you have to start somewhere.
... and welcome to the forums

 

[jrkitching]

I'm wondering if this is a fault with the gearbox, a fault with the actuator, or something else.

Normally I'd suspect the actuator, but in this case, where you've just sent the 'box away to have a new seal fitted (presumably the input seal, that's a common failure point), I'd want to rule out an actual gearbox fault.

Input seal failure is usually the result of a worn input shaft bearing (this is a common and well known issue on manual cars as well), and I'd expect that would have been changed at the same time - they're cheap and readily available. But if for some reason they only changed the seal, a seriously worn input shaft bearing could cause the gearbox to jump out of gear, exactly as it would in a manual car. That said, it's hard to believe a transmission shop wouldn't change this bearing as a matter of course when changing the seal.

If it's an actuator fault, there are no good low cost solutions. You can buy the actuator complete, but individual parts are a different matter. I've seen seal kits on the 'net, generally costing around £200 or so, but there's not much information out there on how to strip and rebuild the actuator. There are a very few suppliers who will recondition your actuator for about £600 or so (google CD Motors in Stoke on Trent); presumably using one of these seal kits. I don't know what sort of turnaround time you could expect.

There are only a few independent garages who would take on the job of fixing this, and I'd expect a main dealer repair to cost £3000-£4000 if a replacement actuator is required. On an 11 yr old 500, it's questionable if this sort of expenditure can be justified. It's worth fitting a new actuator if you can do it yourself and it fixes the problem, but it's a lot of money to lose if this doesn't work.

The biggest problem you have is probably working out exactly what you need to do to fix this.

How long have you had the car, by the way?

 

[bestmotors]

I would suggest you start here
It's a heavy topic, but you have to start somewhere.
... and welcome to the forums

I'm wondering if this is a fault with the gearbox, a fault with the actuator, or something else.

Normally I'd suspect the actuator, but in this case, where you've just sent the 'box away to have a new seal fitted (presumably the input seal, that's a common failure point), I'd want to rule out an actual gearbox fault.

Input seal failure is usually the result of a worn input shaft bearing (this is a common and well known issue on manual cars as well), and I'd expect that would have been changed at the same time - they're cheap and readily available. But if for some reason they only changed the seal, a seriously worn input shaft bearing could cause the gearbox to jump out of gear, exactly as it would in a manual car. That said, it's hard to believe a transmission shop wouldn't change this bearing as a matter of course when changing the seal.

If it's an actuator fault, there are no good low cost solutions. You can buy the actuator complete, but individual parts are a different matter. I've seen seal kits on the 'net, generally costing around £200 or so, but there's not much information out there on how to strip and rebuild the actuator. There are a very few suppliers who will recondition your actuator for about £600 or so (google CD Motors in Stoke on Trent); presumably using one of these seal kits. I don't know what sort of turnaround time you could expect.

There are only a few independent garages who would take on the job of fixing this, and I'd expect a main dealer repair to cost £3000-£4000 if a replacement actuator is required. On an 11 yr old 500, it's questionable if this sort of expenditure can be justified. It's worth fitting a new actuator if you can do it yourself and it fixes the problem, but it's a lot of money to lose if this doesn't work.

The biggest problem you have is probably working out exactly what you need to do to fix this.

How long have you had the car, by the way?

Thank you for your reply.
Brought it like this and gave it to my local mechanic to change the clutch which took him a decade.
Id assume the gearbox specialist would have changed and checked everything needed.
With this vehicle, it doesn't jump out of gear, it jumps in general.
For example creeping in traffic, it would jump and jerk until it hits 2000rpm, when changing to second/third/fourth gear it would jerk slightly but nothing like in first, exactly same in reverse, it would jump all over the place if i throttle it.
If i very very very slightly throttle, (i mean 1% throttle) it would be fine, not jerk.
I've done research and apparently for gearboxes that have oil contamination the flywheel gets hurt, we didnt change the flywheel as it is solid but i've never seen a flywheel do something like this.
I've contacted a few places, some say may be actuator, another has mentioned that i drive it 100 miles, do a calibration and check if the selespeed oil is leaking into the gearbox, some say it may need a complete new gearbox although mine has just been reconed.
Its literally giving me biggest greif possible. Im completely lost.
I've done some personal tests, handbrake on and apply little throttle, the car isnt smooth, its just jerking constantly, non stop.
Same on reverse test, i've checked with a diagnostic tool, the RPM flucuates crazy when doing these tests, at 1000rpm, it drops to 900 constantly, plays around drastically.

 

[jackwhoo]

Gearbox specialists are not dualogic specialists , in fact likely know nothing about the dualogic "robot" attached to the gearbox.

 

[jrkitching]

Its literally giving me biggest greif possible. Im completely lost.

As I think most people, even competent vehicle mechanics, would be in this scenario.

Id assume the gearbox specialist

Was this a gearbox specialist, or a dualogic specialist? Understanding how the gearbox works, and understanding how the dualogic actuating system works, are two completely different things. (edit: I see Jack beat me to it on this one!)

Right now, you don't even know if the fault lies with the gearbox, one or more of the dualogic components, or even something else entirely.

If you have access to a known good actuator, swapping that over might give you a better idea of what's actually going on here.

I'm even wondering if breaking this car for parts might be the best way to extract whatever value remains in it.

 

[bestmotors]

As I think most people, even competent vehicle mechanics, would be in this scenario.

Was this a gearbox specialist, or a dualogic specialist? Understanding how the gearbox works, and understanding how the dualogic actuating system works, are two completely different things.

Right now, you don't even know if the fault lies with the gearbox, one or more of the dualogic components, or even something else entirely.

If you have access to a known good actuator, swapping that over might give you a better idea of what's actually going on here.

I'm even wondering if breaking this car for parts might be the best way to extract whatever value remains in it.

I totally agree, as the gearbox itself is the same as a manual gearbox, the specialist i used only dealt with the manual gearbox side of things, not the selespeed side of things. I'd assume dealing with my wifes Fiat 500, if the selespeed side of things had a fault, id get a fault on the reader.
As there is no faults within the TCM its pushing me towards other possibilities of failure. I am also aware it may just be something manual on the selespeed unit may have possibly failed also. I spoke to a Fiat specialist recommended i top up the selespeed oil (as it was a little low) and drive it 100 miles (it was defo nowhere near drivable though) and check the oil again to see if its fluid level is going down.

 

[spleenharvester]

I totally agree, as the gearbox itself is the same as a manual gearbox, the specialist i used only dealt with the manual gearbox side of things, not the selespeed side of things. I'd assume dealing with my wifes Fiat 500, if the selespeed side of things had a fault, id get a fault on the reader.
As there is no faults within the TCM its pushing me towards other possibilities of failure. I am also aware it may just be something manual on the selespeed unit may have possibly failed also. I spoke to a Fiat specialist recommended i top up the selespeed oil (as it was a little low) and drive it 100 miles (it was defo nowhere near drivable though) and check the oil again to see if its fluid level is going down.

Selespeed (Dualogic) oil should not be going down under any circumstances - it's a closed system. My 2011 500 @ 90k miles has not lost any at all. You most likely have a faulty seal in your unit somewhere. There are a few garages in the country that know how to fully recondition them with new seals and do any repairs - it's usually about £750 - CD Motors Staffordshire for example operate through ebay.

Was it topped up with Tutela CS Speed?