Assembling Front Hubs and Brakes
New Bits from Rally Design
As i've dicussed in another post, I really didn't want to be fitting completely standard front brakes to my Avon, the car is going to be used for a lot of track days, and i'd already seen how it ran out of brakes at Curborough spint circuit, courtesy of Bill Sollis in the Ultimate Kit car DVD. I am also quite concerned with the unsprung weight of the car, so I ordered a Wilwood brake pack(BK1P) and two aluminium hubs (RD752) from Rally Design. Both the aluminium lightweight calipers and the lightness of the aluminium hub design greatly reduce the corner weight of the car. The wilwood powerlite caliper weighs in at just under 1 kilo. Its a simple 4 piston caliper intended for formula cars or other cars of a low weight. Opening the box I was quite alarmed to find a 'for racing use only' sticker. Doing a bit of research it seems as though the caliper does not come equipped with piston dust seals. Although I spoke to several people who said they have run them for thousands of miles on road cars with no trouble. Occasional removal of the pads and a good clean out is all that is required.
I opted for Poly-matrix E pads. Looking at the graphs provided by Wilwood, they looked to give a good balance from cold to hot, staying fairly consistent with a longer wear rate than the Poly-matrix A race pads.
Fitting the Bearings to the Hubs
Quick trip to the local motor factors to get a QH bearing kit (P/N ####), these were quite reasonable at £24.00 for the pair. The kit contains an inner and out bearing and race, grease and split pin. I would have to reuse the wheel hub nut, castelated nut and washer, so I gave them a good cleaning up.
Fitting the bearing races to the hubs is a tricky business, requiring a special bearing tool to ensure the race goes in squarely, so I went to my local garage where I watched my friend Lea hit my lovely new shiny hubs with an unbelievable amount of force using a very large lump hammer! The bearing tool is simply a connical shaped press that fits inside the race and ensures even pressure is applied to push it squarely into the cavity in hub. Its important to go in square as if it doesn't it will distort the aluminium and excessive bearing wear will occur.
With the races in, fitting the bearings is a doddle. The next job is to pack the bearings full of grease, you can do this yourself by working the grease into the bearing with your fingers, however by far the better approach is to use a special gun. The bearing is fitted inside and then grease is crammed into it. Again this is important as excessive bearing wear will occur is it isn't properly lubricated.
Copious amounts of grease was crammed into the bearing cages. The inner seal is then gently tapped into place to prevent grease escaping past the hub and onto the upright.
Fitting the Wheel Studs
Well now this was hard work. Everything I had read said I should be able to pop the stud into the hole and use a wheel nut to lock it into position. Well its a nice theory but mine were too tight to budge. So I spent and hour with a big hammer, balancing the hub on two blocks of wood battering them into position. The wheel studs were longer than the standard Cortina studs, this is because I was planning to fit alloy wheels, the Cortina studs are too short so not enough of the nut is on the stud, the SVA man understandably gets a bit upset at this. Again rally design to the rescue with some 47mm studs (SS36).
Fit the Caliper Bracket
The caliper bracket needs to be attached to the back of the upright, using the M12 30mm bolts provided. I found that the bolts were too long for this job, doing them up to the fullest extent caused the end of the bolt to touch the brake disc. So I switched the bolts for stainless steel M12 25mm bolts and also fitted a washer. I used the original manufacter torque setting of 45-50 ft/lbs to secure these bolts.
Fitting the Disc to the Hub
The brake disc is secured to the inner face of the hub by means of x4 M10 25mm bolts. I switched the orignal mild steel bolts for stainless steel and after ensuring the two faces were free of debris and giving them a good clean with brake cleaner, bolted them together. Again I used the original manufacters torque settings of 30-34 ft/lbs of torque, tightening in stages diagonally. I also put a couple of lines of blue thread lock on these bolts to ensure they stayed put.
Fitting the Hub and Disc to the Upright
Firstly I just double checked the bearing cages were fully packed with grease, then gently fitted the hub assembly onto the spline, you have to give in a good push down to make sure its properly in place, and that the outer bearing is seated correctly. It should be free to turn at this point, I put another good dollop of grease onto the bearing at this point. Place the washer, which should have a peg matching the groove in the spline, ontop of the outer bearing. Tighten up the hub nut until its finger tight. Torque this nut up to 27 ft/lbs of torque and check for full and free rotation of the hub, it should be quite difficult to turn at this point. Now slacken the nut off by 90 degrees. This gives the hub endfloat the required 0.001-0.005 inches of movement. Place the castleated nut ontop of the hub nut and push the split pin through (if the pin wont' fit, move the castelated cover round). Bend the pin out to stop the nut moving. Gently tap the bearing cover into place.
Attach the Caliper to the bracket
The caliper is attached to the bracket by means of two long hex bolts passing through two tubular spacers (to give the required distance). Not sure about a final torque figure for these bolts, will have to do a bit of research with Wilwood, however I suspect 30 ft/lbs or greater will suffice
Check the run out on the disc with a feeler gauge between the disc and caliper bracket. Hopefully there shouldn't be any!
Job Done!
Test fitting the caliper and bracket to the upright
Disc bolted to the hub
Brute force to get the wheel nuts in
Nearly there
Completed hub assembly
As i've dicussed in another post, I really didn't want to be fitting completely standard front brakes to my Avon, the car is going to be used for a lot of track days, and i'd already seen how it ran out of brakes at Curborough spint circuit, courtesy of Bill Sollis in the Ultimate Kit car DVD. I am also quite concerned with the unsprung weight of the car, so I ordered a Wilwood brake pack(BK1P) and two aluminium hubs (RD752) from Rally Design. Both the aluminium lightweight calipers and the lightness of the aluminium hub design greatly reduce the corner weight of the car. The wilwood powerlite caliper weighs in at just under 1 kilo. Its a simple 4 piston caliper intended for formula cars or other cars of a low weight. Opening the box I was quite alarmed to find a 'for racing use only' sticker. Doing a bit of research it seems as though the caliper does not come equipped with piston dust seals. Although I spoke to several people who said they have run them for thousands of miles on road cars with no trouble. Occasional removal of the pads and a good clean out is all that is required.
I opted for Poly-matrix E pads. Looking at the graphs provided by Wilwood, they looked to give a good balance from cold to hot, staying fairly consistent with a longer wear rate than the Poly-matrix A race pads.
Fitting the Bearings to the Hubs
Quick trip to the local motor factors to get a QH bearing kit (P/N ####), these were quite reasonable at £24.00 for the pair. The kit contains an inner and out bearing and race, grease and split pin. I would have to reuse the wheel hub nut, castelated nut and washer, so I gave them a good cleaning up.
Fitting the bearing races to the hubs is a tricky business, requiring a special bearing tool to ensure the race goes in squarely, so I went to my local garage where I watched my friend Lea hit my lovely new shiny hubs with an unbelievable amount of force using a very large lump hammer! The bearing tool is simply a connical shaped press that fits inside the race and ensures even pressure is applied to push it squarely into the cavity in hub. Its important to go in square as if it doesn't it will distort the aluminium and excessive bearing wear will occur.
With the races in, fitting the bearings is a doddle. The next job is to pack the bearings full of grease, you can do this yourself by working the grease into the bearing with your fingers, however by far the better approach is to use a special gun. The bearing is fitted inside and then grease is crammed into it. Again this is important as excessive bearing wear will occur is it isn't properly lubricated.
Copious amounts of grease was crammed into the bearing cages. The inner seal is then gently tapped into place to prevent grease escaping past the hub and onto the upright.
Fitting the Wheel Studs
Well now this was hard work. Everything I had read said I should be able to pop the stud into the hole and use a wheel nut to lock it into position. Well its a nice theory but mine were too tight to budge. So I spent and hour with a big hammer, balancing the hub on two blocks of wood battering them into position. The wheel studs were longer than the standard Cortina studs, this is because I was planning to fit alloy wheels, the Cortina studs are too short so not enough of the nut is on the stud, the SVA man understandably gets a bit upset at this. Again rally design to the rescue with some 47mm studs (SS36).
Fit the Caliper Bracket
The caliper bracket needs to be attached to the back of the upright, using the M12 30mm bolts provided. I found that the bolts were too long for this job, doing them up to the fullest extent caused the end of the bolt to touch the brake disc. So I switched the bolts for stainless steel M12 25mm bolts and also fitted a washer. I used the original manufacter torque setting of 45-50 ft/lbs to secure these bolts.
Fitting the Disc to the Hub
The brake disc is secured to the inner face of the hub by means of x4 M10 25mm bolts. I switched the orignal mild steel bolts for stainless steel and after ensuring the two faces were free of debris and giving them a good clean with brake cleaner, bolted them together. Again I used the original manufacters torque settings of 30-34 ft/lbs of torque, tightening in stages diagonally. I also put a couple of lines of blue thread lock on these bolts to ensure they stayed put.
Fitting the Hub and Disc to the Upright
Firstly I just double checked the bearing cages were fully packed with grease, then gently fitted the hub assembly onto the spline, you have to give in a good push down to make sure its properly in place, and that the outer bearing is seated correctly. It should be free to turn at this point, I put another good dollop of grease onto the bearing at this point. Place the washer, which should have a peg matching the groove in the spline, ontop of the outer bearing. Tighten up the hub nut until its finger tight. Torque this nut up to 27 ft/lbs of torque and check for full and free rotation of the hub, it should be quite difficult to turn at this point. Now slacken the nut off by 90 degrees. This gives the hub endfloat the required 0.001-0.005 inches of movement. Place the castleated nut ontop of the hub nut and push the split pin through (if the pin wont' fit, move the castelated cover round). Bend the pin out to stop the nut moving. Gently tap the bearing cover into place.
Attach the Caliper to the bracket
The caliper is attached to the bracket by means of two long hex bolts passing through two tubular spacers (to give the required distance). Not sure about a final torque figure for these bolts, will have to do a bit of research with Wilwood, however I suspect 30 ft/lbs or greater will suffice
Check the run out on the disc with a feeler gauge between the disc and caliper bracket. Hopefully there shouldn't be any!
Job Done!
Test fitting the caliper and bracket to the upright
Disc bolted to the hub
Brute force to get the wheel nuts in
Nearly there
Completed hub assembly
posted by Charlie at
8:06 PM
1 Comments:
Thanks for the info here - you have helped me out big time! I have just started my build so the brakes are next on the list. When I get my it skills up to date I will start my blog at www.tigeravon.com THANKS, Jon, Fleet, Hampshire
By
Jon King, at 7:30 PM
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