2007+ Fiat 500 Transmission

Quick note: much of this information is based off of North American (Mexico Manufacture) vehicles. The North American fiats are much more straightforward in configuration- with fewer options, models, and variations in powertrains. If you are looking for information for a euro-market 500, please be aware that there may be differences. Creating a subheading detailing these differences is also a good idea.

C510

The C510 is a heavy duty 5 speed manual transaxle found in all turbocharged 500 applications, including all model years of the Abarth and 500t, and all 500s from 2018 onwards. For stock power levels, these are very robust and durable units and generally provide a long service life, especially when maintained properly. Like the X1/9 transmissions, reverse gear is non synchronized. Shifting into a forward gear (or just waiting a long time) after depressing the clutch, and before shifting to reverse is crucial to ensure the longevity of the transmission. Failure to do so can damage not only the reverse gear hardware, but all components in the case due to metal fragments.

Power Handling:

Despite arguably being the weakest link in the powertrain of the modern 500, these transmissions can and will handle a fair amount of torque. Pre 2015 transmissions are happy until ~250 crank TQ, but any more may be pushing the limits. I am searching for more information on the common cause of failure, so that information will be added in the future. Starting in 2015, the C510 got a refresh which includes a more convenient drain plug, and stronger internals.

Service (external):

The C510, unlike the C514 and X1/9 gearboxes, uses a concentric slave cylinder (CSC) which should be replaced any time the clutch is replaced, or the slave cylinder is removed from the transmission- for two reasons. First, it's quite a pain to get to- requiring the removal of the transmission from the engine in order to gain access. Second, CSC's tend to be quite fragile, and most often fail after being agitated- after all, on this type of clutch slave, Moment loads and vibrations applied to the throwout bearing act directly on the hydraulic cylinder.

The input shaft seal is pressed into a steel plate, which clips on the back of the CSC, and mounts to the transmission via two bolts. The plate has no seal of its own, and is supposed to be sealed to the transmission case using an RTV sealant. When replacing the clutch slave cylinder, extra care should be taken to not upset the integrity of the RTV bead sealing the plate, or else a horrendous leak will result. Unclipping the CSC from the plate whilst it is retained on the transmission by RTV alone is quite a challenge...personally, I recommend replacing the seal any time the CSC is removed, as removing and reinstalling the seal after thousands of hours of use and heat cycling is likely to damage it. You do NOT want to repeat the whole job over a $45 seal plate.