Post by colin4255 on Mar 3, 2012 21:37:08 GMT
Looked forever to find out how to do this. Haynes manual was woefully useless and not much info on the web either. Figured it out myself and thought I would share with you.....
If you are going to do this, you will need a full bearing rebuild kit, anything else is a waste of time and money. You really need to swap everything to stop the play in the wheel. There are actually four wheel bearings in the front wheel, two in the hub that the wheel bolts onto, and two in the casting that the shock absorber and brake calliper bolt to. There are two circlips, one large flat ‘D’ washer and two sets of grease seals. You will need to replace them all at the same time. While you are at it, best to replace the brake pads. It’s all available from Beedspeed for less than £40 including the rebuild kit and brake pads, springs and pad pins. See the Help page for a link to Beedspeed.com
You will need:-
Circlip pliers
Screwdrivers - flat and cross head blades
8mm, 13mm, 14mm, 15mm, 16mm and 22mm sockets
3/8 drive ratchet long extension bar and short extension bar
3/8 drive ratchet
8mm and 13mm spanners
torque wrench (ideally)
Copper or hide hammer
Set of good quality Allen keys
Good quality wheel bearing grease – small tub
Decent sized tyres lever (To lever the pivot pin down to make putting the Speedo cable easier to put back)
At the first attempt a couple of hours free time and it helps to have a mate to help too!
What to do:-
You will need to unbolt the wheel, the disc calliper, remove the brake pads, and disconnect the Speedo cable and the bottom of the front shock absorber to remove the hub and the casting.
Start before you even unbolt the wheel, by loosening the hub nut. Its best to do this with the scooter on its stand and front wheel attached because it will take a lot of force to loosen the hub nut and if you try this with the wheel removed you could tip the scooter forwards and off its stand!. A friend to sit on it and steady the thing is a good idea.
To access the hub nut take a small screwdriver and prise off the silver (or black plastic) hub nut cover that is in the centre of the star shaped front wheel hub.
Behind this you will find a split pin holding a castellated metal hub nut cover on. Bend the split straight and pull it out with a pair of pliers. (When you put this back at the end, replace it with a new one!)
Now pull off the castellated metal hub nut cover and you will se the hub nut. You need a 22mm socket and a fairly long bar or ratchet to undo this at it will be very tight (about 55lbs feet of torque) so no cheap sockets or you will wreck the nut and the job will be over before its begun! For now just loosen it but leave it in place.
Now remove the front wheel by undoing the 5 13mm nuts, taking care not to loose the washers.
Remove the front wheel.
Next turn the handlebars so you can get at the rear of the disc, and prise off the plastic cover that goes over the brake pads (in the centre of the disc calliper at the rear)
Next use a very small screwdriver to push off the small circlip that holds the pin that holds in the brake pads. Tap out the pin (it should come loose or can be cajoled out with a pair of pliers) and then remove the spring that holds in the pads and carefully pull the pads out. If they have less than 1.5mm of thickness or are badly scored or damaged, you will need to replace them
Next undo the two Allen bolts that hold the calliper onto the casting and pull the calliper backwards away from the disc. The hose should be long enough for it to sit on the floor away from the hub. FROM NOW ON do not pull the brake lever until you have put the pads back at the end of this process or you will likely push the calliper pistons out of the calliper!!!!
OK, now remove the hub nut you loosened earlier. The hub itself comes off with the disc bolted to it. Do not expect to be able to pull it off, it will appear to be stuck fast. Now for some patience. Take a copper or hide hammer and while holding the star shaped hub at one side, tap the hub from the back at the other (behind one of the wheel studs) towards you. You may have to turn the hub and keep tapping for a while before it comes loose. DO NOT bash the hell out of it. It is cast alloy and will crack or break and a new one is about £100!. You can tap it fairly hard but don’t go mad. Just take your time and persevere and it will come loose eventually.
Once the hub is off you will need to remove the Speedo cable. Undo the 8mm nut that holds the tab that holds the cable in and remove the nut and tab and gently pull the cable out of the Speedo drive. Leave it to dangle to one side
Now undo the two bolts holding the strut to the casting. One will be easy, the other more tricky as it won’t come out all the way. Undo both 13mm nuts and remove the one bolt you can get out and just take the nut off the other bolt that you can’t get all the way out. Don’t worry; we’ll come back to that.
Next, if you look inside the centre of the casting from the wheel side and clean out all the mucky grease, you will see a circlip. Take some circlip pliers and gently open it, then pull it out long the front wheel axle shaft.
Behind the circlip is a flat washer with a D shape in the centre. Fiddle this out too.
Now you will be able to pull at the casting and it will slide out along the hub just far enough for you to be able to remove the remaining shock absorber bolt you couldn’t get out earlier.
Once you have removed the bolt, pull the shock absorber bottom out of the way and you can remove the casting from the hub spindle shaft completely. There should be a thin flat washer left on the hub spindle. Leave this where it is so you don’t lose it or forget to put it back later. Its critical this washer is there as it spaces the casting properly on the spindle.
OK, now we have a hub with disc attached and casting. Each has bearings and seals inside which we need to remove.
The main hub. Clean any grease away from the outer side (where the hub nut is bolted) and you will see the main wheel bearing is held in by a large circlip. Take your circlip pliers and remove this. Turn the hub over and again clean out all the grease you find.
Now will be able to see through the centre of the inner hub bearing to the inside of the outer one. You need a 3/8 drive long ratchet extension and the biggest 3/8 drive socket you can get loosely through the centre of the inner bearing (About 15mm socket from memory).
Put the socket on the extension, feed it through the inner bearing, then take your hammer and hit the inside of the main bearing using your socket and extension until you have driven the main hub bearing out through the side where the hub nut was before you undid the hub. It won’t take a lot of force and it won’t damage your extension bar or socket, but don’t use you best ones to do this! Just make sure you drive it out squarely.
Before you flip the hub over to drive out the inner bearing, you will need to remove the oil/grease seal that is over the top of it and fitted flush with the inner edge of the hub. Lever this off with a screwdriver – you will be replacing it later.
Once the large main bearing is out and you have removed the oil seal from above the inner bearing, take a note of how deep inside the hub the inner bearing is. You can hit the new one a long way in, but all you need to do is hit it in far enough to leave an approx 3mm gap to fit the new seal over it so the top of the seal ends up just below flush with the inside edge of the hub housing when you are done. Measure the depth before you drive out the old inner bearing as you’ll need to put the new one back in only as deep as the old one is.
Flip the hub over so you are looking down the hole where the main bearing came out. Take the extension and I think from memory a 15mm socket (or one that just less than the diameter of the inner bearing (i.e. as close to the same size as the inner bearing but loose enough to fit through the centre of the hub) and lower it through the hole till its touching the inner bearing. Now take the hammer and drive out the inner bearing by hitting it. Its not hard and the bearings will come out easily.
The main hub is now free of bearings and seals.
Next take the casting you removed and clean out all the grease. There are no circlips holding the bearings in the casting, but there is sometimes a small rubber seal between them. The casting has two needle roller bearings in it. Take an appropriate socket and drive them both out at the same time. They are fairly small so it won’t be hard. BEFORE you drive them out, take a note of how far in the housing they are, as you’ll have to put the new ones back in the exact same place.
If you look at the large hole in the casting you will see it has an oil seal in it. Prise this out with a screwdriver, as you will be replacing this with a new one from the rebuild kit.
Make sure everything is clean and free from dirt.
First bearing to go back is the main sealed bearing in the front of the star shaped hub (thee one held in with the circlip). Apply a little wd40 to the outside edge of the bearing and place it squarely in its hole. Take the old main bearing and place it over the new one then tap it back in making sure you keep it square. Drive it all the way in and it will stop as it hits a shoulder in the hub. Make sure its in square and you can see the groove in front of it that the circlip fits in. Put a new circlip back in and that’s the main bearing done.
Flip the hub over and now before you put the inner needle roller bearing in, make sure the hub as plenty of wheel bearing grease in it.
Clean the hole where the needle roller bearing goes and place the bearing squarely in the hole. Use the old needle bearing, or a socket of the same size as the needle bearing and drive it in. Take care here to do this bit by bit until you have it at the same depth in the hole as you measured before you took the old one out – i.e. deep enough to leave room to tap the seal in over it so it fits just below flush with the inside edge of the hub. DON’T drive it in too far, or you will have to drive it back out and possibly ruin the thing.
Gently tap the seal down over it. Check and grease the needle rollers and make sure there’s plenty of grease in the hub and in the needle roller bearings.
Now on to the casting. More of the same. Sit the wide end of it on a flat surface (I put an old towel underneath first). Now drive in the first needle roller bearing to the same depth the old ones were. Again a bit at a time so you don’t drive them in too far. Next put the small rubber seal in. Finally, drive in the second needle roller bearing until it’s just below flush with the outer edge of the casting and again, to the SAME depth as you noted before you took the old ones out.
Grease the needle rollers properly. These don’t actually turn, but the bottom of the hub rocks on them when the suspension moves so they don’t need lathering in grease.
Turn the casting back over and put in the new large seal.
Now we are ready to put it all back together, which is basically a reversal of how you took it to bits.
First slide the casting back over the hub spindle so its flush with the thin washer that we left on the hub spindle.
Before you put the circlip back that holds the washer and the casting in place, you’ll need to re-attach the shock absorber and fiddle in the bolt that only comes out (and only goes back) before you finally locate the casting and fit the circlip. Waggle the casting around so you can get that shock absorber Allen bolt in and tighten it with the nut.
Now take the new D washer that came with the rebuild kit and put that back in – it only fits one way and must go all the way in locating on the ‘D’. It has to go back far enough for you to re-attach a new circlip over it. This is fiddly so make sure the circlip is located properly – took me a few goes to get this right as the casting wants to keep moving about. If you tap it, do it gently so as not to damage the outer edge of the casting. Apply a little grease to the hub spindle.
Once you have the casting securely located with its circlip and you are sure it’s properly located and the clip is properly seated, take the main hub with the brake disc attached and slide it gently onto the hub.
As we left the plastic Speedo drive in the hub, turn it gently as you put it back until you feel the Speedo drive locate on the threaded part inside the hub.
Now you can put the hub nut on and tighten it. NOTE there is NO WASHER below the hub nut. Odd though this is, Vespa did not put any washers below the hub nut on the PX Disc and MY disc, it just tightens s directly onto the bearing.
Now you can rebuild the brakes, put the calliper back and put the wheel on. Once the wheel is on, tighten the hub nut to about 55lbs feet of torque and put the castellated hub nut cover back on and a new split pin in. Put the grease cap back on and you should be done… That was easy!!!
If you are going to do this, you will need a full bearing rebuild kit, anything else is a waste of time and money. You really need to swap everything to stop the play in the wheel. There are actually four wheel bearings in the front wheel, two in the hub that the wheel bolts onto, and two in the casting that the shock absorber and brake calliper bolt to. There are two circlips, one large flat ‘D’ washer and two sets of grease seals. You will need to replace them all at the same time. While you are at it, best to replace the brake pads. It’s all available from Beedspeed for less than £40 including the rebuild kit and brake pads, springs and pad pins. See the Help page for a link to Beedspeed.com
You will need:-
Circlip pliers
Screwdrivers - flat and cross head blades
8mm, 13mm, 14mm, 15mm, 16mm and 22mm sockets
3/8 drive ratchet long extension bar and short extension bar
3/8 drive ratchet
8mm and 13mm spanners
torque wrench (ideally)
Copper or hide hammer
Set of good quality Allen keys
Good quality wheel bearing grease – small tub
Decent sized tyres lever (To lever the pivot pin down to make putting the Speedo cable easier to put back)
At the first attempt a couple of hours free time and it helps to have a mate to help too!
What to do:-
You will need to unbolt the wheel, the disc calliper, remove the brake pads, and disconnect the Speedo cable and the bottom of the front shock absorber to remove the hub and the casting.
Start before you even unbolt the wheel, by loosening the hub nut. Its best to do this with the scooter on its stand and front wheel attached because it will take a lot of force to loosen the hub nut and if you try this with the wheel removed you could tip the scooter forwards and off its stand!. A friend to sit on it and steady the thing is a good idea.
To access the hub nut take a small screwdriver and prise off the silver (or black plastic) hub nut cover that is in the centre of the star shaped front wheel hub.
Behind this you will find a split pin holding a castellated metal hub nut cover on. Bend the split straight and pull it out with a pair of pliers. (When you put this back at the end, replace it with a new one!)
Now pull off the castellated metal hub nut cover and you will se the hub nut. You need a 22mm socket and a fairly long bar or ratchet to undo this at it will be very tight (about 55lbs feet of torque) so no cheap sockets or you will wreck the nut and the job will be over before its begun! For now just loosen it but leave it in place.
Now remove the front wheel by undoing the 5 13mm nuts, taking care not to loose the washers.
Remove the front wheel.
Next turn the handlebars so you can get at the rear of the disc, and prise off the plastic cover that goes over the brake pads (in the centre of the disc calliper at the rear)
Next use a very small screwdriver to push off the small circlip that holds the pin that holds in the brake pads. Tap out the pin (it should come loose or can be cajoled out with a pair of pliers) and then remove the spring that holds in the pads and carefully pull the pads out. If they have less than 1.5mm of thickness or are badly scored or damaged, you will need to replace them
Next undo the two Allen bolts that hold the calliper onto the casting and pull the calliper backwards away from the disc. The hose should be long enough for it to sit on the floor away from the hub. FROM NOW ON do not pull the brake lever until you have put the pads back at the end of this process or you will likely push the calliper pistons out of the calliper!!!!
OK, now remove the hub nut you loosened earlier. The hub itself comes off with the disc bolted to it. Do not expect to be able to pull it off, it will appear to be stuck fast. Now for some patience. Take a copper or hide hammer and while holding the star shaped hub at one side, tap the hub from the back at the other (behind one of the wheel studs) towards you. You may have to turn the hub and keep tapping for a while before it comes loose. DO NOT bash the hell out of it. It is cast alloy and will crack or break and a new one is about £100!. You can tap it fairly hard but don’t go mad. Just take your time and persevere and it will come loose eventually.
Once the hub is off you will need to remove the Speedo cable. Undo the 8mm nut that holds the tab that holds the cable in and remove the nut and tab and gently pull the cable out of the Speedo drive. Leave it to dangle to one side
Now undo the two bolts holding the strut to the casting. One will be easy, the other more tricky as it won’t come out all the way. Undo both 13mm nuts and remove the one bolt you can get out and just take the nut off the other bolt that you can’t get all the way out. Don’t worry; we’ll come back to that.
Next, if you look inside the centre of the casting from the wheel side and clean out all the mucky grease, you will see a circlip. Take some circlip pliers and gently open it, then pull it out long the front wheel axle shaft.
Behind the circlip is a flat washer with a D shape in the centre. Fiddle this out too.
Now you will be able to pull at the casting and it will slide out along the hub just far enough for you to be able to remove the remaining shock absorber bolt you couldn’t get out earlier.
Once you have removed the bolt, pull the shock absorber bottom out of the way and you can remove the casting from the hub spindle shaft completely. There should be a thin flat washer left on the hub spindle. Leave this where it is so you don’t lose it or forget to put it back later. Its critical this washer is there as it spaces the casting properly on the spindle.
OK, now we have a hub with disc attached and casting. Each has bearings and seals inside which we need to remove.
The main hub. Clean any grease away from the outer side (where the hub nut is bolted) and you will see the main wheel bearing is held in by a large circlip. Take your circlip pliers and remove this. Turn the hub over and again clean out all the grease you find.
Now will be able to see through the centre of the inner hub bearing to the inside of the outer one. You need a 3/8 drive long ratchet extension and the biggest 3/8 drive socket you can get loosely through the centre of the inner bearing (About 15mm socket from memory).
Put the socket on the extension, feed it through the inner bearing, then take your hammer and hit the inside of the main bearing using your socket and extension until you have driven the main hub bearing out through the side where the hub nut was before you undid the hub. It won’t take a lot of force and it won’t damage your extension bar or socket, but don’t use you best ones to do this! Just make sure you drive it out squarely.
Before you flip the hub over to drive out the inner bearing, you will need to remove the oil/grease seal that is over the top of it and fitted flush with the inner edge of the hub. Lever this off with a screwdriver – you will be replacing it later.
Once the large main bearing is out and you have removed the oil seal from above the inner bearing, take a note of how deep inside the hub the inner bearing is. You can hit the new one a long way in, but all you need to do is hit it in far enough to leave an approx 3mm gap to fit the new seal over it so the top of the seal ends up just below flush with the inside edge of the hub housing when you are done. Measure the depth before you drive out the old inner bearing as you’ll need to put the new one back in only as deep as the old one is.
Flip the hub over so you are looking down the hole where the main bearing came out. Take the extension and I think from memory a 15mm socket (or one that just less than the diameter of the inner bearing (i.e. as close to the same size as the inner bearing but loose enough to fit through the centre of the hub) and lower it through the hole till its touching the inner bearing. Now take the hammer and drive out the inner bearing by hitting it. Its not hard and the bearings will come out easily.
The main hub is now free of bearings and seals.
Next take the casting you removed and clean out all the grease. There are no circlips holding the bearings in the casting, but there is sometimes a small rubber seal between them. The casting has two needle roller bearings in it. Take an appropriate socket and drive them both out at the same time. They are fairly small so it won’t be hard. BEFORE you drive them out, take a note of how far in the housing they are, as you’ll have to put the new ones back in the exact same place.
If you look at the large hole in the casting you will see it has an oil seal in it. Prise this out with a screwdriver, as you will be replacing this with a new one from the rebuild kit.
Make sure everything is clean and free from dirt.
First bearing to go back is the main sealed bearing in the front of the star shaped hub (thee one held in with the circlip). Apply a little wd40 to the outside edge of the bearing and place it squarely in its hole. Take the old main bearing and place it over the new one then tap it back in making sure you keep it square. Drive it all the way in and it will stop as it hits a shoulder in the hub. Make sure its in square and you can see the groove in front of it that the circlip fits in. Put a new circlip back in and that’s the main bearing done.
Flip the hub over and now before you put the inner needle roller bearing in, make sure the hub as plenty of wheel bearing grease in it.
Clean the hole where the needle roller bearing goes and place the bearing squarely in the hole. Use the old needle bearing, or a socket of the same size as the needle bearing and drive it in. Take care here to do this bit by bit until you have it at the same depth in the hole as you measured before you took the old one out – i.e. deep enough to leave room to tap the seal in over it so it fits just below flush with the inside edge of the hub. DON’T drive it in too far, or you will have to drive it back out and possibly ruin the thing.
Gently tap the seal down over it. Check and grease the needle rollers and make sure there’s plenty of grease in the hub and in the needle roller bearings.
Now on to the casting. More of the same. Sit the wide end of it on a flat surface (I put an old towel underneath first). Now drive in the first needle roller bearing to the same depth the old ones were. Again a bit at a time so you don’t drive them in too far. Next put the small rubber seal in. Finally, drive in the second needle roller bearing until it’s just below flush with the outer edge of the casting and again, to the SAME depth as you noted before you took the old ones out.
Grease the needle rollers properly. These don’t actually turn, but the bottom of the hub rocks on them when the suspension moves so they don’t need lathering in grease.
Turn the casting back over and put in the new large seal.
Now we are ready to put it all back together, which is basically a reversal of how you took it to bits.
First slide the casting back over the hub spindle so its flush with the thin washer that we left on the hub spindle.
Before you put the circlip back that holds the washer and the casting in place, you’ll need to re-attach the shock absorber and fiddle in the bolt that only comes out (and only goes back) before you finally locate the casting and fit the circlip. Waggle the casting around so you can get that shock absorber Allen bolt in and tighten it with the nut.
Now take the new D washer that came with the rebuild kit and put that back in – it only fits one way and must go all the way in locating on the ‘D’. It has to go back far enough for you to re-attach a new circlip over it. This is fiddly so make sure the circlip is located properly – took me a few goes to get this right as the casting wants to keep moving about. If you tap it, do it gently so as not to damage the outer edge of the casting. Apply a little grease to the hub spindle.
Once you have the casting securely located with its circlip and you are sure it’s properly located and the clip is properly seated, take the main hub with the brake disc attached and slide it gently onto the hub.
As we left the plastic Speedo drive in the hub, turn it gently as you put it back until you feel the Speedo drive locate on the threaded part inside the hub.
Now you can put the hub nut on and tighten it. NOTE there is NO WASHER below the hub nut. Odd though this is, Vespa did not put any washers below the hub nut on the PX Disc and MY disc, it just tightens s directly onto the bearing.
Now you can rebuild the brakes, put the calliper back and put the wheel on. Once the wheel is on, tighten the hub nut to about 55lbs feet of torque and put the castellated hub nut cover back on and a new split pin in. Put the grease cap back on and you should be done… That was easy!!!
my question is,,once i get the hub off, will it damage the seal when i remove it from the axle? and thus a new one will need to be fitted?ive never had to do this job before until now,disc is proper worn 
