Is it OK to change the centers betwen holes in the rear hub by making larger holes which are offset desired amount (in my case from 108 to 100 mm) and press fit inserts with internal thread for bolts? See the picture.
I would like to use my 15 inch alloys instead of buying new ones. Thanks.

[Edited on 27/2/07 by dpavlov]

Why dont you just drill new holes at the correct pcd, in between the existing holes.?

Al.

A bit risky imo but I suppose its all down to the quality of the inserts. I would be more inclined to just drill four new holes mid way between the old ones - you could call it a multi fit hub then!

I think the inserts would be fine if they fitted tightly into the hub, but I think you are making more work for yourself. As others have said I would re-drill the hub between the existing holes, if this is possible.

Yes i know that it would be easier to drill new hole between the existing ones, but there are already to large holes (22 dia) for acces to bearing housing bolts. I could squeeze new holes between them but dont like the idea of so many holes. It would look much better that way. I think? On the other side it would give me couple of mm more material for thread. And if threads strip I could easily change insert.

One more question!
I have rear hubs and bearig housing from my sierra donor with rear drums. How do I convert this to disk brakes. From which car can i get suitable calipers and discs. Dont tell me from another sierra with rear disc brakes as I doubt I can find some. I already had trouble to find this one.

Not sure what calipers are available where you are, but many calipers can be made to fit, especially as you will have to fabricate mounting plates to fit behind the bearing housings, it should be fairly easy to find suitable calipers. Iv'e used citroen/peugeot calipers as they have a cable operated handbrake. If you can get away with a hydraulic handbrake, your choice is wider still, even bike calipers can be made to fit.

Al.

sounds like a good plan providing you can make the holes in the right place - most likley would need to use a mill as a drill would wander off into the existing hole.

then the inserts must be plenty strong enough.

what about welding the holes up and drilling them out again?

Only reservation I have is if a wheel should pop off and and accidnet occurs, what will the insurance company say about these mods?

I'm not an engineer but I believe welding and redrilling of hubs is illegal in my country (NZ). I have a similar problem in that I want to use a set of 5x108 pcd wheels (Ferrari) on my Mazda MX5 - sourced suspension. Can't redrill the wheels ços the olts are a visible part of the design, can't redrill the hubs ços the face plate is too small a diameter and antway there just isn't enough room to go from 100x4 to 108x5 - check out the geometry, one stud would be virtually on top of an existing one. So I'm left with trying to get hubs made or adapt existing ones to the mx5. Anyone know what would fit?

Just a thought ... You might consider an adaptor - 10mm thick steel should do it. Countersunk bolts securing it to the hub and new studs at the correct pcd for the new wheel.

yep, I'd thought of that but also illegal round here because the geometry is too tight. You'd need to have a spacer thick enough for two bolts to be on top of eachother when going from 4x100 to 5x108. I've been told 32mm thick would be the minimum for that particular swap. 4x108 to 5x108 is OK or 5x100 to 5x108.

I still think this is the best and safest solution. Loads of meat left for strength.
Rescued attachment hub drilling.jpg