HQ Disc Brakes - The Highlights!

[Rogue Trooper]

Back on the old site I had a thread going that had a lot of valuable information in it regarding the HQ front disc brake conversion. I'm transferring the informative bits here as there was some valuable information there that shouldn't be lost. If the thread appears disjointed it's because I've only transferred the posts with relevant information.

[Rogue Trooper]

Hi

This has been discussed at length here and on a couple of other forums but a lot of answers are vague to say the least hence my question here.

I am looking to fit a set of HQ disc brakes to the front of my 83 SWB CF. It seems to be generally agreed upon that machining the stub axle is a no-no and the disc itself should be machined out to fit the standard wheel bearing so I'm OK with that and should be able to get this done without too many issues.

This conversion seems to be a popular one and has been done many times before so there is one thing left to do after fitting the disc and that is mounting the caliper itself to an adaptor plate to allow it to fit up to the disc.

My question revolves around this backing plate. Does anyone have a template for this or a set of measurements or plans to construct one. This has been done many times before so there must be someone out there with the details. I'm trying not to have to reinvent the wheel here (pardon the pun) if I don't have to so any assistance would be greatly appreciated.

I tried emailing The Rodshop in Aus as they have various parts listed that seem to suit this conversion but their answer to my question was less than helpful. Bear in mind that I'm in NZ too so if you're able to spend a little time answering this one many thanks in advance.

[Rogue Trooper]

[user]worzel[/user]
 

Hi,
I've just replaced the wheel bearings (and the stub axle, oops) so i know my beddy has hq disks and the stub axle hasn't been machined.
The stub axle is from a later model CF (slightly larger dia than the early models)
for mine (and maybe yours):
inner bearing Koyo L68149/10
           or Timken L68100/L68149
outer bearing ZWZ K07100S/K07210X
    and same no. Timken
oil seal   PBR TC12134 (1.812" id, 2.500"od, 0.375" wide
hope that's some use
         

[Rogue Trooper]

The bearing information above was spot on and I have a disk fitted up. On to the next question.

There is a washer that sits up against the outer bearing that looks like this...



And it sits where you can see in this photo a couple of galvanised washers I have used to allow the nut to do up and hold the disk in place.



The original washer is a bit too thin and wide now to be of use so for you chaps that have used the standard HQ disk, what did you use to replace this washer?

Thanks

[Rogue Trooper]

[user]worzel[/user]
 

i had a look,the kit from CRS comes with a special washer 38OD 19ID and 5.27mm thick
this washer tapers at 45' on the inside so the ID on the side facing the bearing is about 25.4 (1")
On my beddy a thin section of tube (about 2mm thick) has been tacked onto inside of washer -oops- didn't measure it when it was off, can do it if you need it.
send your e-mail and i'll send you photos as it is to complicated for me to post them

[Rogue Trooper]

[user]Busy[/user]
 

Rogue Trooper, where is the split pin hole in relation to the end of the nut? Can't see it in the photo.
Don't forget there is a cage thingy to go on the nut which has a bit of length which the split pin goes through

[Rogue Trooper]

Yep, got that thanks Busy. It's all sitting just below the disk out of shot with the remains of the front drum assembly.

The current setup in the photo is just to hold the disk in place to ensure the bearings are running true with no play. It is not even close to a finished product. Even the disk is a second-hand throw away item that we were just using to test the measurements boring out the disk for the new bearings rather than munt the new ones.

[Rogue Trooper]

[user]Busy[/user]
 

The old CF washer should do the trick (is what I used), remember there re 3 types of nuts for these, the nut and cage (type shown in pic), the nylon lock nut and the crown nut (looks like a crown), all 3 are different lengths.

The hardest bit about these HQ conversions are the dust caps, can't remember exactly why, could of been the HQ caps where two short

[Rogue Trooper]

Nope, afraid not. The old washer is too large a diameter. Possibly because I have an 83 van and maybe the hubs were larger but regardless, the washer does not butt up to the bearing but hits the disk instead. Even if the washer was turned down it would be too thin as the stub axle runs out of thread before the nut butts up to the washer.

Worzel is sending me pics of what he has but it looks like I will have to have something suitable made up to do the job. Something with a smaller outside diameter so it sits up snugly to the bearing but thick enough to allow the nut to tighten up against it leaving room for the cap and split pin.

[Rogue Trooper]

[user]worzel[/user]
 

postage fron oz for the adaptor plates would only be $30 tops, everything else is avaliable in NZ.

now be patient, this might hurt a bit.....
I'm trying to do the photobucket thing, but i'm not very clever



page 1 of instructions (if it happened)



page 2



page 3

i will try to take a photo of the washers but it's tricky without a tripod.
hope it worked because i just spent an hour of my life (and more importantly an hour of my monthly dial-up quota) trying something new