WHEEL BEARING REPLACEMENT

(project by Ivo Molák)

PARTS TOOLS

Time needed: 20 minutes. (including hands washing)

Difficulty: Not difficult, if you have the right tools ;-)

Hub with bearing assembly for a vehicle without ABS (original FIAT) is just slightly more expensive (approx. 5,-) than an aftermarket bearing alone.

Besides the usual tools for wheel removal

1. 32mm socket, minimum 25mm deep !!

2. A decent lever

3. 8mm Allen socket (hexagon)

4. Screwdriver and a small hammer

 

WARNING NOTES by Geoff Bowles

There are 2 different types of wheel bearing one for cars with ABS and one for cars without. If you fit the wrong one on to a car with ABS the ABS warning light will come on as the bearing contains sensors to tell the ABS computer if a wheel is spinning or locked (skidding). Because the sensor effected is motion related the warning light may only come on at certain speeds.

(In the UK a car will fail the MOT test if the ABS warning light is on)

The last time I drove my barchetta, I described how the ABS light came on after a few minutes cruising on the motorway, following the replacement of a rear wheel bearing. When I had the car connected to the diagnostic computer, it retrieved a message to say that the ABS system had detected a phonic wheel with the wrong number of teeth. The phonic wheel is a toothed ring on the inside of the bearing, which the ABS sensor uses to measure wheel speed. My new bearing didn't have a toothed wheel but came with a magnetic implant which - I assumed - was there to do the same job I have spoken to those who supplied the part. They say that there are different parts before and after a certain chassis number, and agree they supplied the wrong part for my car. I'm still a little baffled (as were DTR) as to why the ABS light only comes on when cruising at 70-80 mph on the motorway, and not when using the brakes.... When I changed the bearing, and installed new rear discs and pads, I happily road tested the car round my local country lanes with no problems....!

The main problem I had was that one of the little studs that holds the brake disc on had corroded and seized. They're very soft metal and difficult to remove without damage, so it might be worth replacing those too...

 

WHAT YOU HAVE TO DO

STEP

ACTION
1
Remove wheel and (distance)spacer

 

2
With an 8mm Allen, unscrew the 2 bolds (in yellow circles) holding the brake caliper.

3

Pull off the brake caliper (DON'T REMOVE THE HYDRAULIC HOSE)
4
Remove brake disc
5
Remove cap, using a screwdriver and hammer
6
Losen the 32mm nut (VERY tight!!)
 
7
Remove Nut (1) spacer (2) and hub (3). The hub comes off easily
 
8
Install new hub, spacer and nut
9
Install the new bearing in the opposite order to the way the old one was removed