Testarossa rear wheel bearing removal and replacement
|I have had a little clunk for a while, seems speed related and
goes away quickly. No load, right hand corners it comes back. I
figured it's most likely to be the inner wheel bearing so I went
about pulling it apart to have a look.
Seemed easy enough after I looked at the picture in the parts manual and had a look at the WS manual.
|So first step, jack her up and rip the wheel off.
Then remove the brake calliper. To do this I removed it from where the solid steel line to the calliper meets the flexible line and I unbolted it. Then I fed the steel line out behind the hub, moved the calliper out of the way and then reconnected it to the flexible line so as it didn't just leak everywhere.
It will empty the reservoir otherwise as it's lower that the level.
Next step was to remove the disc. To do this you have to release the handbrake by turning the rotor until the small hole is at the top and you can see the little winder through the hole. Put the screw driver at the top and wind the winder towards the bottom, downwards. This releases the handbrake tension and you will then be able to pull the disc off.
Because I needed to do some cleanup in this area I stripped everything off the hub starting with the handbrake shoes, cable, adjusters and springs and set these aside.
Next to remove were the six 8mm cap screws that hold the end of the CV joint to the stub axle components. These are a right PITA and are bloody tight. An 8mm hex key in a 1/2 drive socket worked for me, but on the wheel side it was more difficult. There isn't sufficient clearance behind the nuts to get a ring spanner on there and I was forced to use a 17mm open end spanner. Not happy about that. Might have to make something better for this stage when it comes to putting it all back together.
Once the half shaft and CV joint is clear then remove the two long bolts that hold the hub to the upper and lower control arms. The hub is heavy so be ready to take the weight.
Here's an image of the dirty old hub removed from the car and stripped down ready for cleaning.
|That little round nut in the middle of the photo is Part 10 on
the drawing above. It's the nut that holds it all together. This nut
should be pretty tight, there will be a torque setting for this
somewhere, maybe Steve M will have that on hand.
Anyway, it will be a mess, covered in grease as this is where the CV joint bolts up. So here I am cleaning all this black goo out of there and I can feel something moving around. When I get enough of the mess cleared I can see that this nut is loose and is just rocking on the indents where it locks into the shaft. Once I knocked those indents out, I actually removed this nut with my fingers! Not good.
This tells me that a bearing has collapsed a little and allowed the clamping tolerances to be lost, probably causing my noises.
Anyway, once the nut was off, over to the press and press the shaft out of the hub. The larger 'outer' bearing will come out of the hub and stay on the shaft.
Remove the steel plate at the rear that holds the seal and then press the inner bearing out of the hub. There is a steel bracket on the hub for the hand brake lower pivot and a bracket to hold the brake line. Once those are clear the hub is ready for cleaning.
You will need a bearing splitter for the press to remove the outer bearing, this could be tight. Mine took 16t to shift it.
Do not remove the outer ring PART 16 from the hub. This will be rusty and will take some time to get clean, but judicious use of the sandblaster will clean it all up better than new. Once the hub is clean remember to thoroughly clean it to ensure ALL remnants of the sandblaster have been removed.
I cleaned up all of the parts and then primed them before painting. The hub is done in Wurth silver and the rest of the components in Wurth satin black.
|The new bearings will be here tomorrow and then I'll put it all
back together again.
Here's some pics of the car minus it's rear RHS assembly.
|When it's time to re-assemble the components there are a couple
of torque settings that you need to be aware of:
The ring nut
securing the axle shaft flange to the rear wheels shaft"
The large cap screws, which secure the CV joint to the axle
|The LHS hub is fitted and the handbrake mechanism is installed.
|The next part of the process was to repack the outer CV joint
and fit it to the hub.
When pulled this off it was a black greasy mess, full of nice clean (black) Moly grease. In the removal process I popped out the bearings, central cage and the inner carrier and laid everything on the bench in the way it came out, or so I thought!
After cleaning and repacking with new Moly grease I was ready to fit this back together but something was niggling at the back of the mind.
At the end of the axle shaft there is first a cupped washer. Not quite flat but with a little bit of cupping to it. This fits to the axle with the cupped side facing outwards. Then you slip the CV joint on, and it's held in place by a small circlip that drops into a fine slot at the end of the axle shaft.
On the actual centre carrier of the CV joint there is one raised face and the other side is flat. I wasn't sure which way this went back in and no amount of reading was going to tell me.
I had planned to do the other side anyway, but next week or when I had some time, but this CV joint was bugging me and I knew that the only way to know for sure was to pull down the right side!
This time I grabbed the camera to take some step by step shots.
Remove the alloy arm that locates the rear stabiliser bar. Next you remove the 6 large cap screws at the back of the CV joint around where the rubber boot seats. Then remove the handbrake components from the hub and remove the top control arm bolt. This will allow you to 'fold' the hub down and pop it off the CV joint.
You can also see in the second picture that I have totally removed the calliper out of the way, but reconnected it to the brake line to stop fluid leaking everywhere. If you have stock rubber brake lines, use a brake line clamp, but I wasn't going to dent my braided stainless lines.
|With the grease wiped away from the end of the CV joint and the
circlip removed, the CV joint is ready to come off. Don't forget to
remove the rear band clamp and slide the boot off!
Looking at the face of the inner race of the CV joint, you can see that it is flat. No raised section. This told me that I had put the other side together wrong so I next went on to rectify the mistake and finish the installation of the LHS.
|Here's a picture of the CV joint looking from the rear. Looking
at the inner carrier you can see the raised lip that I have
referenced. This is the CORRECT orientation. If you ever pull the CV
joint down, make sure you put it back together this way.
Second picture is the correct orientation looking from the front of the CV joint where it blots to the axle flange. Also VERY important here is the actual placement of the inner carrier. It is impossible to fit back together in any other way. It's worse than Rubik's cube!
Note in the picture how the large lands on the inner race line up with the small lands on the outer race. Big to small, small to big. If you try and re-assemble the CV joint in any other way, you won't get the 6th ball into the carrier and if you do, it will all lock up and destroy itself on the first revolution.
|Once it's all apart, then the cleanup process begins. Everything
was either sandblasted, wire brushed or both. Be very careful
sandblasting the hub assembly. The alloy cleans up really well
although there is a very tough base primer under that grime that
takes a lot of moving. Allow a good hour in the sandblaster to clean
up the hub. Most importantly, make sure it is really clean, blow it
out with compressed air and then wash it if you can. You must make
sure that EVERY little bit of sand, grit and dust is removed before
painting and re-assembly. There are bearings in here that will be
cut to bits with sandblaster residue.
Once everything is clean, repainted and as good (or better) than new, start to put it back together.
Here is the first step. Fit the V seal, spacer washer, bearing and spacer tube to the axle shaft. Stretch the V seal around the spacer washer. It's a tight fit but when it's on there make sure it lines up flat along the bottom of the washer and then slide this onto the axle shaft.
Inside the spacer tube the axle is raw steel and there was some dusty surface rust when I pulled it down, both inside the tube and on the shaft. I painted inside the tube and greased the shaft just to give it some rust protection for the future.
Here are the components all ready to press back together.
|Once the bearing and tube spacer are pressed on, it's very
important to ensure that the V seal on the bottom is not folded
under. Both of mine were and I think this is just the way that the
bearing applies pressure when in the press.
Take a very fine screwdriver and VERY carefully insert it under the rolled in lip of the seal. Then slowly push the seal around until it folds out flat against the rear of the bearing, making a perfect dust seal. You can see in the second picture that the V seal is laying perfectly flat against the rear of the bearing. It must look like this before you go any further.
|Here is the hub with the rear bearing all ready to be pressed
|Then take the completed stub axle and press it in from the other
side. You will feel it seat on the rear bearing. If it pushes the
rear bearing out a little, just roll it over and fully seat the rear
bearing. It's a good way to check that they are pressed tightly
together anyway and that there is no slack left for the ring nut to
|Here's the hub in the press, pushing the rear bearing into the
hub carrier and onto the outer axle shaft. I did it this way on the
RHS and then changed for the LHS. Both ways worked fine so it
doesn't matter which order the two bearings go in.
|Next step is to fit the rear bearing retainer. Spread a light
coating of Hylomar over the mating surface as specified in the WSM.
Hylomar is a non curing sealant that lasts pretty much forever. It has been used by Rolls Royce since the start of time and is recognised as one of the best products in the World. It's available in aerosol cans as a spray, tins as a paint on sealer, or tubes which I used. Costs about $10 for a small tube which is enough to do thirty or forty Testarossa hubs!
Grease the new seal on the inner and outer face and in particularly between the two lips of the seal as this creates a second level of defence against dust and water ingress and also lubricates the seal.
I also smeared a light coating of grease onto the six retaining studs. You have a steel on ally situation here that is prone to corrosion, so either a smear of grease or some 'copper eezy' will avoid future issues. Tension these studs as per the previous settings. Be sure to get the correct orientation. The flat section goes where the big hole is at the top of the picture where the handbrake cable goes in.
|Don't forget to fit the brake line bracket in place before you
do up the six studs that hold the bearing retainer.
Now is a good time to paint those six studs and nuts. Don't wait till they are back on the car as access is too difficult. If you have the time to send all of your nuts and brackets out to the cad platers, then you are already winning here, but for those without the time, make sure that you paint all of your exposed nuts and bolts as the freshly cleaned steel will corrode in days.
Now fit the outer flange in place. Make sure that you have a liberal coating of grease to the nose where the seal runs and don't tear your new seal as the flange penetrates it.
Just line up the splines and very gently push it home. If it's too tough, use a rubber hammer and gently tap it till it enters the seal. Once the initial restriction passes it will slip on pretty easy.
|Now the tricky bit!
You need to fit the washer and then the ring nut and somehow do up that ring nut to 168 ft-lb without damaging your handywork.
Fit the hub back into the lower control arm and slip the bolt into place. Support the control arm with a jack and lift it so that the hub can lay over and is parallel to the ground.
The best way to stop this rotating for me was to use a large Phillips head screwdriver through the wheel stud hole in the outer flange plate and stick this into the rectangular hole where the hand brake cable comes through. Use the biggest one that will fit and you won't damage the threads in the flange plate.
You can see in the picture that the head of the screwdriver is holding the weight of the hub and the jack has elevated the lower control arm so that I can work on that ring nut in a comfortable manner. It has to be done up very tight so make sure your access is comfortable and non restrictive.
|Once you get the ring nut up to the required specification, use
a pin punch and indent the top of the ring nuts into the axle
flange. This locks the nut. You can see in the pictures that the nut
did up to a slightly different spot that the yellow painted original
position. This is a good thing as you are denting fresh metal. If
you are unlucky and the ring nut lines up with the original marks,
then replace the ring nut as the metal is brittle and will not take
a second set of impacts.
If I lived in the USA or UK where parts were a day away I would have replaced the ring nuts anyway. I don't like to use components like this twice. At around $40 USD each, just replace them. At Australian parts prices of $272 each plus 21 days out of Italy, mine were reused. Fortunately they both locked in different places on fresh metal.
The workshop manual specifies a Ferrari special tool AS 7783 to do up this ring nut.
Basically this is a hardened steel tube spanner with four square lugs inside of it that fit into the slots in the ring nut. Not having access to the Ferrari service tool I had to make one. Figured I'll be doing the other car some day and needed the tool anyway.
I took a good quality 29mm 1/2 drive socket. This is a really good fit over the ring nut and the outer wall of the socket lined up perfectly with the inside edge of the square holes in the ring nut.
The slots in the ring nut measure 5.9mm and I could only get 6mm x 6mm tool steel bar so I had to linnish it down on one side by 0.1mm to make a snug fit into the ring nut slots.
Then I cut strips of the tool steel and using a TIG welder, attached these to the outer shell of the 29mm socket. I actually used the ring nut with a standard hose clamp around it to hold the tool steel in place whilst I welded them to the socket. This made sure they fitted 100% into the ring nut.
Once welded I oil hardened the tool twice prior to use. It is a perfect fit and worked really well.
First tension to 100lbs, then in increments up to 169 ft lbs.
|Fit the CV joint up next and make sure that the circlip is
firmly seated into the slot, nice and even all the way around. Just
tap it with a fine drift punch or screwdriver until it rotates
freely in the slot and is sitting even all the way around. Fit your
CV boot and clamp back to the other side. I purchased new stainless
banding clamps and the required fitting tool from a CV / driveshaft
specialist locally. These are far superior to the original folded
clamps and allow a much tighter fitment.
Liberally pack the flange face with Moly grease and then simply fold the hub up and offer it to the CV joint. Fit off the 6 nuts and cap screws to a firm tightness. These are tensioned at a later time.
|Whilst you are working on one side, get the wife involved!
Here's Suzie painting all of the exposed nuts and bolt heads and threads after assembly of the LHS whilst I was fitting up the RHS hub.
Amazing how much patience women have for tedious tasks!
Whilst she's in the shed, assemble the handbrake mechanism and fit your rotors. Then she can sit in the car and work the handbrake lever whilst you get the tension correct. About three to four clicks to full on is what you are aiming for.
|Leave the wife sitting in the car, lift up the hoist and fit off
the callipers. Then have her assist in the calliper bleeding
process. She will love you for it........
pump, pump, hold............
There are two bleed nipples on each rear calliper. Start with the lower one first. 7mm ring spanner, clear tube into a glass jar with 1/2 inch of fresh fluid in the bottom.
Lower nipple first, then upper nipple then go to the other side of the car and repeat.
Once your brakes are adjusted, have the
'assistant' hold their foot on the brake very firmly and then torque
up your CV bolts. 58 ft-lbs.
|Have fun in the shed.............................|