One of the best things about a Fiat 500 Abarth is how much fun they are to drive. Part of the enjoyment comes from the easy shifting, heavy duty C510 5-speed gearbox that comes standard in the Fiat 500 Abarth and 500 Turbo models.
The C510 transmission in these models is strong and can handle much abuse, as dished out by modded Abarths with over 300nm (221bs. ft) of torque, but as you get more miles on your car, you may notice shifting becomes stiffer as the shifter hangs up to the right or left side of the shift pattern and doesn't spring back to neutral. If that is the case stick around and we'll get your car shifting like new in no time!
The Fiat 500 Abarth and Turbo shift linkage pivot shaft can become oxidized and stick in its housing, causing your shifter inside the car to not spring back into neutral. At rest and in neutral, your shifter should spring back by itself and stay in the middle of the shift pattern, If you have to force the shifter back side to side, you likely have a sticking pivot shaft.
You can try popping the inside shift boot up and spraying some white lithium grease, etc., into the ball socket under the shift knob to see if that helps, but if it still sticks, you should look into the fix below. Besides taking the enjoyment out of shifting your car, the increased effort can wear out your shift cable(s) and possibly internal components inside the transmission.
Identifying the Issue
This issue isn't with the back and forth effort, but the side to side motion. You can test this by when in neutral pushing the lever to the right towards the 5 / reverse gear gate and letting go. The shifter should quickly snap back to the 3rd / 4th gear gate or center of the shift pattern, Try this a few times and if the lever hangs up or needs to be guided back, you likely have a sticking side to side pivot shaft. Luckily this is an easy to fix issue, and just requires some grease and a little time and patience.
Note: Click on the pictures to enlarge them for easier viewing
Getting Started: Fiat 500 Abarth Battery Tray Removal
Take the negative battery cable off first. The small ground wire (arrow) going to the ECM also needs to be removed. Remove the positive battery cable next. Isolate the cables so they don't fall back onto the battery and arc.
To get to the shift linkage, you need to remove the battery and battery tray. Here, I'm undoing the battery hold down bolt.
Removing the battery hold down bolt. Note, the hold down bolt is long, as are all the bolts holding the battery tray, and they take some time cranking to unscrew them.
A tip is if the bolts/nut start to get harder to unscrew, spray some penetrating fluid on them and then screw them back in a few turns. Do this every time the fasteners start feeling like they are getting harder to unscrew. By doing this, you will clean the threads and redistribute some lube into them, and it will avoid breaking or stripping the fastener.
There are three fasteners holding the battery tray down. Two on the side are bolts and the one in the center, which is a nut. When you reinstall them, a tip is to load them up with anti-seize because, being under the battery, they are prone to corrosion.
The ECM is attached to the battery tray and comes out with it, so you need to remove the connectors. Carefully pull the yellow clip connector locks open.
then pull the levers up. There are two. When the lift the levers up the connector disengages from the ECM. Be careful when you do this work. Lift the connector straight up so you don't damage the delicate pins in the ECM.
One the ECM connector is off, you have to go around the battery tray and unclip the harness hold downs. Here I am using a flat-head screwdriver to carefully lever the clip out of its receptacle on the battery tray. There are a few wire harness hold down clips that are secured to the battery tray that have to be disengaged from the tray so you can pull it out.
Be careful with these as it is important to secure the wiring harness to keep it from moving around while driving. Being sloppy and breaking them and then not replacing or securing the harness can catch up to you in the form of bad connections and weird electrical issues down the road.
There is a hold down for a sensor in front the of the battery tray. Push the connector from the back to pop it free.
Another cable hold down clip on the side of the battery tray being removed with a bent Trim Stick tool.
Sometimes you can push the clip out from the back.
The wire harness runs under the battery tray and these clips help hold it into place. Just pull the harness out.
You can now remove the battery tray/ ECM unit.
Back view of the ECM and battery tray unit. Put it safely aside and treat it like the expensive item it is.
Doing the Job: Greasing The Fiat 500 Abarth C510 Trans Shift Linkage
Once the battery tray is out, you can see the Fiat 500 Abarth shift linkage located on the C510 transmission case. It is way back, so be prepared to lean over to get at it.
The issus is the external pivot shaft that runs through the case starts to get stuck and hard to swivel. A lack of grease and climate conditions are prime reasons for this. The arrow points to the shift shaft that runs through the case.
The pivot shaft is held in simply by this nut. It is a good idea to mark the position of the shaft in relation to the surrounding area. This will help you put back everything in the same position.
An extension and a swivel joint will make getting at the nut easier.
Here's some perspective on where we are working. Don't be intimidated by the location, there is room to get to everything you need to get to.
When the nut was loosened, I removed the shift cable in the back from the pivot shaft lever. To do this, I used a thin 13mm wrench and stuck it under the cable joint and pulled up, popping it free from the ball socket. The picture above just illustrates how I did the rear cable. Leave the front cable attached.
Once the nut is loose, unscrew it with your fingers. Take your time to make sure you don't drop it. Note on the right side is a rubber boot covering the vertical shift shaft the runs straight up and down into the transmission internals. The little shift lever we are removing fits into a cutout in the vertical shift shaft (there is another picture below that shows that upclose). I carefully pulled back the rubber boot on the vertical shift shaft to see how the levers fit together. It only goes in one way so don't be concerned.
Another image of how the little shift lever fits into the vertical shift shaft. When everything is bolted back up, all these parts will line up and fit together perfectly, so don't be concerned. After I removed the nut, I removed the washer and the little shift lever. It is keyed to the shaft.
Once the nut, washer and lever is removed, you can push the pivot shaft out. It comes out from the back. If it hits the shift weight behind it, you can have someone carefully inside the car pust the gear shifter slightly forward to give more room for the shaft to be withdrawn from the rear.
Before you remove the lever, it is a good time to try pivoting the shaft back and forth to feel the resistance. It should move smoothly and easily. If it does, than you may have another issue, possibly with the cables, the shifter or something else. However, as you are more than half way through with the job, you might as well complete it by greasing the pivot pin anyway. Mine was binding and not letting the inside shifter spring back to the center of the shift pattern.
Before I disassembled the pivot shaft, I had tried spraying lube on the shaft every day for a week and then working the shifter inside the car.The lube didn't make a difference and there was no trace of the lube I had been spraying.
Withdrawing the shift linkage pivot shaft. This is the part of the shift mechanism that moves back and forth when you go side to side in neutral with the shifter inside the car. The little lever attached to it that you removed pushes the vertical shift shaft up and down inside the transmission.
Inspecting the shaft, it was in good shape, but devoid of lube, and had signs of oxidation and sticking. Note the cutout at the end for the lever that was removed. The little shift lever is keyed so there is no adjustment.
I used the brass brush above and some polish to clean up the shaft, being careful not to to strip the original plating off of the shaft. Once that's removed, the shaft will be even more susceptible to oxidation and rust, etc.
A look down the external passage on the transmission where the shift lever shaft passes through. Luckily there wasn't any signs of damage, or corrosion. I cleaned it out with a rag and some light oil like WD40.
This is the little shift lever showing the orientation it faces when being put back on the shift shaft.
The pieces removed Side to side shift pivot shaft and lever, washer and fastening nut.
Grease the pivot shaft. I used a synthetic grease that has good water repellency qualities. Keep the grease off the threads because you should use loctite or a new self locking nut to secure this when done.
The rubber boot is peeled back to show the cut out in the vertical shift shaft where the shift lever we removed fits into.
Slide the greased pivot shaft back into its passage, place the small shift lever onto the shaft (it is keyed to fit onto the pivot shaft). and fit the end on its right side into the notch on the vertical shift shaft. Once you slide the washer on and secure the nut, everything will line up tight.
Showing how the small shift lever fits into the notch on the vertical shift shaft. I put a dab of grease on the end.
Fitting the washer and then the nut onto the shift shaft.
Snap the rear shift cable onto the ball socket on the shift shaft arm. You can just use your fingers as it snaps on quite easily.
Nest, tighten the nut holding the shaft and lever together (that's what the arrow is pointing at). There are no specs for tightening this nut. It should be tight enough to secure it, but not too tight to bind the shift shaft. A new self locking nut or loctite will take any concerns away from the nut backing out over time.
The most tedious part of the job is stretching the boot back over the shift lever. Take your time to do this and don't rip the boot! Mine got caught in the notch on the shaft and was fidgety to free up. I could have just unbolted the lever, but that would have made it too easy! LOL
This isn't the greatest image, but looking at the boot's left side, the boot is positioned on the little shift lever where it is supposed to be to keep dirt from getting into the vertical shift shaft that runs into the transmission.
After that, put back your battery tray, making sure all the wire harness clips are fasternd and anchored down, hook up your ECU (Note: make sure you hook the ECU first before your battery!) and then your battery (don't forget to clean your terminal connectors if they are dirty).
But before you are done:
Cleaning the Fiat 500 Abarth Ground Strap
Before you put the battery tray back, it is a good time to look at the ground cable located under the battery tray that runs from the frame rail to the transmission. These can corrode and it is good preventative maintenance to unbolt the cable, and clean the mounting surface. Bad grounds and battery connections contribute to many vehicle issues, so do yourself a favor and spend a few minutes on this preventative maintenance.
Simply unbolt the cable, clean the connections and put some dielectric grease on them. On the braided cable, using some anti-corrosion spray like Fluid-Film is a good idea.
On my car, the ground cable wasn't too badly oxidized and resistance measurements were fine. but I ran into a problem removing the bolt holding the ground wire to the transmission, so I replaced the ground cable and the bolt.
Part numbers that fit my 2012 Fiat 500 Abarth:*
- Fiat 500 Abarth Ground Strap: 68073597 AA
- Ground Cable Hold-down bolt at transmission: 68145957 AA
Easier Alternate Fix - Replace Fiat 500 Abarth Shift Bracket and Housing Assembly
If you've read this far and are thinking this is too much work, you can order a new Shift Bracket and Housing Assembly for somewhere around $100. A tip is to check Amazon and other online sources to compare prices.
Fiat 500 Abarth and Turbo C510 Transmission Shift Cable Bracket part number 68095119AA *
*Contact your dealer or check the Mopar website to confirm part numbers.
Disclaimer: This is how I greased the linkage and changed the ground strap on my Fiat 500 Abarth and is provided for informational and entertainment purposes. If you have any doubts on you ability to perform this work or have any issues, I recommend having it done by a professional. I am not responsible for any issues arriving from you reading this post. Use at your own risk.
Inspiration: Side to Side Stiff - Shift Cable Sticking? thread on the Fiat 500 USA Forum
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