Manual Trans compatibility questions

[Rosso Dolce]

Hi everyone - I have a 2012 500 Sport that I purchased new, currently has about 22,000 miles. This car is only used for pleasure drives to and from frequent autocross and TrackNight use. It is modified with Eibach lowering springs, RoadRace Motorsports rear sway bar, short ram intake, & timing controller. I have camber bolts and run 2 degrees negative camber with 1/2" spacers. Upper & lower chassis braces. Had Powerflex bushings in front control arms, but local expert race shop went back to stock arms after PowerFlex bushing failed - bad fitment or design. Also have PowerFlex lower torque arm insert and I "poured my own" upper motormount with liquid poly, making it now a virtually solid mount. Stock shifter & cables.

I had a problem of trans jumping out of 2nd gear under hard left cornering when modulating the throttle during autocross maneuvers - never happens during street driving. I am usually running 200 treadware performance tires.
Local shop found that the shift lever arm shaft in the trans had a very shallow slot in the shaft where the detent ball drops in to hold in place for the gear selection. They ordered a Fiat replacement part and it had a deeper squared off slot and more positive engagement. Problem seemed to be resolved for most of this past season, only re-occuring during our last local autocross.

Now we can get to my question! Does the Abarth transmission offer heavier duty internals than my Sport, and will an Abarth transmission easily swap in? Any other suggestions/mods for keeping second gear engaged?? I am typically the only Fiat at our local events and hold my own, usually running solid mid-pack RAW & PAX times, but I would like to drive more with two hands rather than worrying about sudden gear changes to Neutral!

Thanks for any help ...

[aelfwyne]

The Abarth trans is heavier duty, yes. However, you will likely not be happy with the gear ratios, as they're a bit longer than the Sport, to aid in economy and reduction of wheelspin. You'll likely end up with a less responsive gear ratio. Also, the Abarth trans has an internal slave cylinder & a different clutch, so you'd have to swap the clutch and possibly replace the hydraulic clutch line.

Assuming you did all of that....

The Sport's transmissions don't typically fail the way you're describing. Your problem is likely unique to your car, especially as it's an early production (2012) vehicle. It may have a defect, or simply have had a revision later to fix the issue. Any chance you can compare the shifting of your Sport to a later model Sport and see if the movement feels similar?

Oh, and finally, if you do replace the trans, don't use one from a Pop, they are geared higher as well for fuel economy, and you'll find it also not as snappy.

[sportfan]

Someone on here in the past had the poping out of gear problem also. I believe it was related to a change they made with the torque arm. On the Powerflex bushing problem, if your car has the stamped out control arms like my 13' Sport, Powerflex never made bushings that would fit them. They were listed to fit it but, the rear bushing would only fit the heavy cast control arms on the Turbos and Abarths. The reason I know this is I won a set of Powerflex bushings and tried to put them on my car. I checked their website and I had the correct part number for my car. I called Powerflex and talked to one of their engineers about it. He had me send him a picture of my control arms. He got back to me and said they didn't know ( in England) that American 500 Sports (or Pops) had stamped steel control arms. They thought that all of our Fiats had control arms like the Abarths. All of this was around the end of last year so by now Powerflex may have bushings for the stamped control arms. To be able to use the bushings I won , I made what I call the Frankenarms. I bored the ball area bores out a little and pressed in new NAPA ball joints. Then I bored out the area where the rear bushing goes, made a sleeve, and then tackFiat Control Arm (1).jpgcontrol arms (1).jpg welded the sleeve in. I added a pound of steel flat metal to each arm to make them more ridgit and had them powder coated.

[Rosso Dolce]

Thank you for this information! The gear ratios would absolutely be a factor - I think you are correct about running changes/revisions to early cars. Unfortunately, in the Pittsburgh area, I am literally the only guy doing fun stuff with a Sport - very few Abarth's, too. Option would be to try to find one on a used car lot and take a test ride - probaly frowned upon by dealer, though...

Are later model Sport trans a compatible swap??

Thank you again for your information & input!

[Rosso Dolce]

Sportfan -
well that certainly makes sense about the stamped arms! Great job on those Frankenarms! I still have the replacement bushings Powerflex sent to me for the failed one, but at this point, I will wait to either do a mod as you have done or look at the Uniball setup again.
Thanks again!