Hello all,
my name is Ari, I'm from Finland and I have a driveshaft problem. Or at least I think so.
The problem car is a Croma 1.9 TDI, 150 hp, auto box, 260000 kms (160000 miles). It shakes at 25-30 km/h (around 15-20 mph) and no, it's not the roadwheels, I change them every spring & fall without any effect to the shake.
So it's a different symptom than the infamous 40 mph shake - I've experienced that too earlier, it got fixed by changing the inner CV joint of the right driveshaft. But pretty soon after that the car developed this low-speed shake.
I borrowed some test equipment from work & attached a sensor to the motor. It shakes at 10-11 Hz, which is quite exactly 3x the rotational frequency of the roadwheel at that speed. And the CV joint has three grooves, right? So with this ingenious diagnose I started to find for help. After that it's been a mild nightmare, two garages trying to find and fix the fault.
First an independent garage changed the left inner CV. After all, the right one had just been changed, so it surely could not be wrong? But, no help. Six months after that, a FIAT garage opened both inner CVs and found that there was significant wear in the right inner joint, which had been running maybe 30000 kms (20000 miles). They changed the joint to an original FIAT part and the shake went away for a moment, but very soon started again, getting gradually worse. So surely it must be the left one this time (they said seeing wear marks in it when they had it open). So they changed the right inner CV, again to an original part, with absolutely no effect to the shake.
I asked to get the changed part and the "tulip" shows some polishing marks but no wear that could be felt by a finger. Several experienced mechanics have also investigated the changed "tulip" and say it definitely is not worn to a point it would cause vibration, so it was changed unnecessarily. An experienced mechanic test drove the car and says the vibration with 99% certainty comes from driveshafts.
At this point I finally got p****d off. The original FIAT driveshaft parts are specific for the auto box, they come from Italy (takes 2-3 weeks) and are hideously expensive. I have paid a LOT of money and my car still shakes. So I stated a reclamation, either wanting my money back or the car fixed for what I've already paid. After all, now both inner CVs are under FIAT's 2 yr warranty for parts and work. As a response, the FIAT garage has promised to investigate the car again for free, and then we would "agree for the fix and the price". The problem is, in my eyes they have totally lost their credibility, and I certainly have become a pain in the butt for them. They may try to suggest some new expensive repair that I can't agree just to get rid of me.
So after all this rant, sorry, background info, I have a few specific questions.
- Has anyone of you experienced this kind of low-speed shake? If you have, what was the cause and how did you fix it? I searched the net and found nothing useful. I repeat: it's not the roadwheels.
- I strongly suspect that the right inner CV has failed again after only 20000 kms (or much less, it's been shaking since early summer). But can an original FIAT part really fail that fast???
- Based on all complaints about driveshaft related shakes, and how people sometimes get them fixed by small things like repacking the joints with grease, it seems likely that Croma's engine-transmission packet is somehow inherently prone to resonate due to even a weak stimulus. So how about the engine mounts, do they become "loose" by age without actually failing? What makes me think about this is that when it's cold (below freezing point) the shake much less notable in the beginning of a journey, but becomes more prominent when the engine warms up.
All help and suggestions really are appreciated.
my name is Ari, I'm from Finland and I have a driveshaft problem. Or at least I think so.
The problem car is a Croma 1.9 TDI, 150 hp, auto box, 260000 kms (160000 miles). It shakes at 25-30 km/h (around 15-20 mph) and no, it's not the roadwheels, I change them every spring & fall without any effect to the shake.
So it's a different symptom than the infamous 40 mph shake - I've experienced that too earlier, it got fixed by changing the inner CV joint of the right driveshaft. But pretty soon after that the car developed this low-speed shake.
I borrowed some test equipment from work & attached a sensor to the motor. It shakes at 10-11 Hz, which is quite exactly 3x the rotational frequency of the roadwheel at that speed. And the CV joint has three grooves, right? So with this ingenious diagnose I started to find for help. After that it's been a mild nightmare, two garages trying to find and fix the fault.
First an independent garage changed the left inner CV. After all, the right one had just been changed, so it surely could not be wrong? But, no help. Six months after that, a FIAT garage opened both inner CVs and found that there was significant wear in the right inner joint, which had been running maybe 30000 kms (20000 miles). They changed the joint to an original FIAT part and the shake went away for a moment, but very soon started again, getting gradually worse. So surely it must be the left one this time (they said seeing wear marks in it when they had it open). So they changed the right inner CV, again to an original part, with absolutely no effect to the shake.
I asked to get the changed part and the "tulip" shows some polishing marks but no wear that could be felt by a finger. Several experienced mechanics have also investigated the changed "tulip" and say it definitely is not worn to a point it would cause vibration, so it was changed unnecessarily. An experienced mechanic test drove the car and says the vibration with 99% certainty comes from driveshafts.
At this point I finally got p****d off. The original FIAT driveshaft parts are specific for the auto box, they come from Italy (takes 2-3 weeks) and are hideously expensive. I have paid a LOT of money and my car still shakes. So I stated a reclamation, either wanting my money back or the car fixed for what I've already paid. After all, now both inner CVs are under FIAT's 2 yr warranty for parts and work. As a response, the FIAT garage has promised to investigate the car again for free, and then we would "agree for the fix and the price". The problem is, in my eyes they have totally lost their credibility, and I certainly have become a pain in the butt for them. They may try to suggest some new expensive repair that I can't agree just to get rid of me.
So after all this rant, sorry, background info, I have a few specific questions.
- Has anyone of you experienced this kind of low-speed shake? If you have, what was the cause and how did you fix it? I searched the net and found nothing useful. I repeat: it's not the roadwheels.
- I strongly suspect that the right inner CV has failed again after only 20000 kms (or much less, it's been shaking since early summer). But can an original FIAT part really fail that fast???
- Based on all complaints about driveshaft related shakes, and how people sometimes get them fixed by small things like repacking the joints with grease, it seems likely that Croma's engine-transmission packet is somehow inherently prone to resonate due to even a weak stimulus. So how about the engine mounts, do they become "loose" by age without actually failing? What makes me think about this is that when it's cold (below freezing point) the shake much less notable in the beginning of a journey, but becomes more prominent when the engine warms up.
All help and suggestions really are appreciated.