Fiat X1/9 Abarth Swap Drive Line

[TonyK]

Although the Fiat X1/9 is over 40 years old the drive line in the new Fiat 500 Abarth is similar.

The rear bearings from the X are the same size as the new Abarth. The only difference is that the new Abarth uses tone rings on the bearing seals to provide the counts or pulses for the ABS system and Soeedometer signal.

The Fiat Abarth hub on the left and the X on the right. Yes the splines are the same as well.
The left side half shaft is 3/16" too short so a flange spacer is installed on that side with longer hub bolts. The right side the shaft is too long and must be shortened. A custom adapter must also be made. I have two videos that explain the process and failure.

TonyK.

Grimsby Ontario Canada.

 

[kmead]

Thank you for posting these.

A couple of questions (stupid ones I am sure, these are the first of what I am sure will be many).

• Are you retrofitting the Abarth bearings with tone rings into the X uprights? This seems like it would make things easier from the cursed computer and its beloved sensors standpoint. Unless of course they won’t actually fit due to the X upright’s geometry.

• Regarding the first video, it is not clear to me why you are not using the stock Abarth output shafts and CV mounts on the transmission side. Are the OE CVs more of a tripode system without a specific CV or ? It is just not clear to why you were making the changes to the Abarth transmission parts and now making new ones.

Thank you for posting these videos and your clear, concise descriptions in the videos of what you are doing and why. Really nice work.

Thank you.

 

[JimD]

It is always very interesting to see what you are up to Tony. Excellent videos. Of course, the only part I really felt qualified to tackle is in the second video where you whipped out Fiat tool #BFG to precision tune the axle. That is in my wheelhouse.

 

[TonyK]

Thank you for posting these.

A couple of questions (stupid ones I am sure, these are the first of what I am sure will be many).

• Are you retrofitting the Abarth bearings with tone rings into the X uprights? This seems like it would make things easier from the cursed computer and its beloved sensors standpoint. Unless of course they won’t actually fit due to the X upright’s geometry.

• Regarding the first video, it is not clear to me why you are not using the stock Abarth output shafts and CV mounts on the transmission side. Are the OE CVs more of a tripode system without a specific CV or ? It is just not clear to why you were making the changes to the Abarth transmission parts and now making new ones.

Thank you for posting these videos and your clear, concise descriptions in the videos of what you are doing and why. Really nice work.

Thank you.

No Stupid Questions.

Not reto fitting Abarth Bearings with tone rings on the driven wheels of the car as I want wheel spin and do not want the computer to cut the throttle should it occur. The bearings for the drive wheels of the Abarth and the X are the same size, so we have a current supply of rear X bearing from the Abarth Front drive axle.

As for the Stock Abarth half shafts, one issue is length or width of the Abarth Track compared to the X. The Abarth uses Tripoide assembled shafts. On the right side of the car it uses a long shaft with a pillow block mounted to the engine block to keep the length between the CV's the same on both sides of the car.

TonyK.

Grimsby Ontario Canada.

 

[kmead]

Proceeding directly to the next question, I presume that due to the track width difference of an X versus a 500 chassis that the “short” axle shafts would be too long? And despite shortening them the angles from outer cv to pillow block or outer CV to Tripode joint would be too great and likely cause bind and short part life?

Thus why you made new stub axles from the tripode stubs with X CV mounts.

 

[TonyK]

Partly correct. The X uses soft steel shafts where the Abarth uses smaller diameter case hardened shafts. In applications of stress welding case hardened steel is asking for trouble and failure. The left side of the car half shaft is not modified, the X shaft adapter snaps into the Abarth transmission, but it is 3/16" to short, so a spacer is installed on the flange of the spline adapter. The right side uses a custom adapter that the hardened shaft is interference fit -.005" pressed together. The hardened shaft is captive, what stops it from spinning are 2 pins milled in on the shaft sleeve line that are then TIG welded. This way the right side of the transmission gets the correct amount of engagement with the splined shaft.

TonyK.

Grimsby Ontario Canada.