If I wanted to convert, lets say a Sierra hub to the same pcd but with 5 studs, what would I need to do? Im guessing I would keep one hole but need to
drill 4 more at the correct spacing, would I need a dividing head for that?
and what about the splines that stop the studs from turning, is this something I could do or is it a machine shop jobby?
thanks
Do you really want to weaken the part of the car that holds your wheels on?
quote:
Originally posted by edspurrier
Do you really want to weaken the part of the car that holds your wheels on?
Same pcd? Granada 5 stud hubs will bolt on to give you a pcd of 112 which with wobbly wheel nuts can accomodate 2mm difference if required.
A dividing head is the way to do it properly.
Cheapo way is to get a brake disk that fits your hub but that is drilled to your required bolt pattern. Clamp them together then attack it with a
pillar drill, using the disk as a template.
The splines are on the studs, not the holes, so don't worry about that.
The wheel is centred by the central spigot part of the hub, not the studs, so you can get away with the odd hole being 0.5mm off centre. Worked OK
redrilling my sierra hubs to 4x100 to match my VW Golf front uprights.
Hope this helps
Tom
I've got some Granny rear hubs that had been coverted the other way (5 stud down to 4 stud) somewhere. They worked ok and took some abuse on the back of one of my old grassers.
The wheel should locate on the centre of the hub anyway, I would fill the holes with weld before drilling new ones then follow Tom's advise with a disc.
i drilled cortina hubs to 5 bolt. used a lathe to mark a circle, punched marks using an online pentagon calculator, and drilled with a pillar drill.
4500miles later still going strong with no wobbles.
you'd have to weld up some of the holes before you could re-drill
but if you wanted to change a granny hub from 112mm to a 108mm PDC you could just drill 5 new holes inbetween the old ones - no welding needed
(they should be far enough away from the old ones that way, but you'd need to draw it up th check)
Think you are missing something here, the hubs are drilled for the wheels, the discs/drums just fit over the studs or the bolts go through to the
hubs.
The way to do this, if you must, is to use an adaptor ring which uses recessed nuts to bolt the ring to the original bolt holes but presents the new
required bolt/ stud pattern forward, this will add atleast 5pm probably 10pm that will need to be compensated for by different wheel ET or wider
arches.
No such thing as a frelunch
[Edited on 3/8/10 by snapper]
Thanks for all the comments, people.
quote:
Originally posted by djtom
The splines are on the studs, not the holes, so don't worry about that.
quote:
Originally posted by snapper
Think you are missing something here, the hubs are drilled for the wheels, the discs/drums just fit over the studs or the bolts go through to the hubs.
The way to do this, if you must, is to use an adaptor ring which uses recessed nuts to bolt the ring to the original bolt holes but presents the new required bolt/ stud pattern forward, this will add atleast 5pm probably 10pm that will need to be compensated for by different wheel ET or wider arches.
Redrilling a wheel hub is a great way to kill yourself and others.
Also never weld a wheel hub.
Hubs are hardened steel if you weld the holes you will temper the steel to a lower hardness.
I sort of know 'cos i tried it the other way round welding up the holes in a disc which converted the cast iron into high tensile steel and the
carbide lathe tools would not touch it!!
The "splines" are on the new studs and they cut a matching spline on the hub when you press them in.
I have alloy hubs on the front which are a similar size to steel ones but alloy is about half the strength of steel.
On this basis you only need 2 studs anyhow for the shear forces transmitted by the wheel/brake disc.
I guess you will get a few doom and gloom comments but it seems a reasonable hypothesis to follow.
PS On reflection I would not do it lightly. It depends exactly where the new holes are in regard to the existing. remembering that there are all sorts
of holes/ribs etc on hubs depending on the type. Apart from shear there is pull out strength of the hib to consider. Is there room to fit a
reinforcing ring behind the hub so you sandwich the drilled hub so to speak?
[Edited on 3-8-10 by v8kid]
Dinosaurjuice Where did you get your pentagon calculator I googled it but could not see anything relevant?
just did a simple CAD drawing of the situation (easy way to work out distances etc)
looks OK to me, also back of Sierra hub is flat, no ribs to deal with
Most likely material for a hub on a mass production car is SG Cast iron ----- don't weld highly stressed components unless you fully
understand what material you are welding, the metalurgy involved and any required post weld heat treatment.
[Edited on 3/8/10 by britishtrident]
quote:
Originally posted by britishtrident
Most likely material for a hub on a prouction is SG Cast iron ----- don't weld highly stressed components unless you fully understand what material you are welding, the metalurgy involved and any required post weld heat treatment.
[Edited on 3/8/10 by britishtrident]
quote:
Originally posted by interestedparty
I'm really not seeing what you are getting at here, why can't I drill new holes as above, if necessary welding up the existing?
what size holes have you put in that sketch ? (the hole you need for the spline is a little bigger than 12mm)
also I would normally take the min. safe distance between hole centres to be 2.5 x the diamiter
quote:
Originally posted by v8kid
Hubs are hardened steel if you weld the holes you will temper the steel to a lower hardness.
quote:
Originally posted by britishtrident
quote:
Originally posted by interestedparty
I'm really not seeing what you are getting at here, why can't I drill new holes as above, if necessary welding up the existing?
Some things you have to take on trust unless you want to spend 4 or 5 years at studying Mechanical Engineering or Materials Science at the few universities that still teach it.
quote:
Originally posted by mcerd1
but can I just ask - why do you need a 5x108 PCD ??
quote:
Originally posted by interestedparty
quote:
Originally posted by mcerd1
but can I just ask - why do you need a 5x108 PCD ??
Sure, to fit wheels with that stud pattern.
quote:
Originally posted by mcerd1
couldn't you just use hubs off a mk2 focus ?
quote:
Originally posted by v8kid
Dinosaurjuice Where did you get your pentagon calculator I googled it but could not see anything relevant?
Ta for the link Dino - just what I need.
Sierra rear hub is hardened steel I know cos I tried turning one down.
Fiesta rear hub fits into sierra bearings and is same length but has smaller splines shaft on CV. Is loads lighter though I wonder if the
sierra/fiesta CV,s can be mixed and matched?
Instead of welding up the holes, i thought in PPC recently (ish) they industrial glued in some lumps of metal to fill the existing holes - means the one that is 5.3mm away has more to push against.
quote:
Originally posted by MikeR
Instead of welding up the holes, i thought in PPC recently (ish) they industrial glued in some lumps of metal to fill the existing holes - means the one that is 5.3mm away has more to push against.
quote:
Originally posted by interestedparty
quote:
Originally posted by mcerd1
couldn't you just use hubs off a mk2 focus ?
I think they are 4 stud, but in any case its a question of whether they would fit the sierra upright. I like your thinking though, if I could find a 5 stud hub that would fit the sierra upright I would be sorted, and no need for dire warnigns of deth too!
blimey - what size allen key do you need to undo that!?!?! 
You know those ones you get with your furniture at ikea...
surely can't be right, those and Argos flat pack keys are made from sub standard metal - and would surely round off if you tried to undo that hub.