This Article is the hard work and research from Shep of Classic Crown. WIth the moving of the Classic Crown site to Mulpiply and the pending closure of the Geocities site this article is hosted on I have reproduced it here as it is a great article and is the step by step guide I based my MS53 wagons fron brake upgrade on. All Kudos fo rthe work goes to Shep.


My Crown Project - By Shep from Classic Crown.

Brake Upgrade Page

Conversion from the MS50, 60 and 70 series solid front disc brake to using the Holden HQ to HZ disc and calipers.

First off this is not a major job just plan everything before you start I spent maybe 4 weeks planning for this project, that includes the ordering of the disc’s, I was going to use some secondhand disc’s but the machining shop was a bit apprehensive about drilling a new stud pattern so close to the Holden stud pattern a fear of cracking between the bolt holes, so opted for new disc’s. this Is a fairly easy job for anyone who has a good background in auto mechanics, if you are unsure do not attempt this project.

The brakes being used for this project are front disc’s (HQ-HZ) Crown MS65 Stub Axles, and HQ-HZ calipers PBR, the rear brakes are MS 112 disc brake axle/diff housing, the Booster/master cly are from a Subaru AWD around the late 90’s model with the Approx 22 mm bore (15/16th's). The front wheel bearings are the same! But you need to use the Toyota bearing seal for this to work! And the Disc pads, wheel bearings, caliper kits are the same for both the Holden and Toyota.

There is no major gain or loss in the wheel track, from the measurements I have taken (see how these measurements where taken (see below) the measurement was taken from the top ball joint locating hole center and the front face of the disc using a straight edge and tape measure, the measurement for the MS65 disc is 150mm, the same measurement for the HQ disc is 152mm. You will need to purchase two new discs $90.00 each, part #DBA014U (U stands for Undrilled)

I also got a workshop to drill the stud pattern for me to suit the Toyota stud pattern.

I also got the workshop to machine out the bearing hub on the back of the disc so I could use the Toyota style seal, and also got the outside edge of the back bearing hub machined off so the stub axle bolts will not interfere with the disc.(see the pics on this page)

You will also need to drill out the locating boltholes for the calipers, (where they bolt up to the stub axle) Holden use a smaller bolt compared to the 12mm bolt Toyota uses.

Any metal fabrication machine shop will be able to do this work for you, just have the measurements of what you want done prepared before hand.

You can also use the Toyota brake lines as they screw straight into the caliper, same thread.

Now for the rear brakes! Here I have opted for the MS85 drum brake rear end, Larger drums than the MS55’s, so over all I think I will have a really good brake setup. I replaced the Wheel cly and Shoes and that is all I have done to the brakes, as to the diff housing the coil spring hardware was removed and I made new brackets to weld onto the diff that locate onto the leaf spring rear end of the project. The Diff housing has been changed to the MS112 Disc Brake


Please view the following pics of the front disc’s so you understand what I have done here!



The following pics are the changes I made to the disc.
I had the outside edge of the bearing housing machined off , approximately 4mm in and 7mm down the outside edge, this was to make sure that there was enough clearance to clear the nut or bolt that hold the stub axle together, maybe I could have used different bolts or turned the heads of the bolts around to clear the bearing housing, but with heat expansion and wear and tear I thought this was a better way to go.

See below for the before and after pics Note: the first pic is and old disc off an Holden HZ, the second pic is a brand new disc. Showing the machined area.




The next two pics show a before and after. I wanted to be able to use the genuine Toyota wheel bearing seal.
I had a engineer to machine out the area where the seal fits to accommodate the Toyota seal. He had to machine out approximately 1.5mm. See pics below.




The cost of this project so far is. $160.00 for two DBA 014U discs (U stands for Undrilled, no stud pattern).$90.00 for the machining work to be carried out.$20.00 for 10 wheel studs (secondhand off Toyota Hilux 4X4 80 model, longer stud) Wheel bearing kits and brake caliper kits, $77.00

So far the preliminary tests of the brakes are very positive, and feel really good.The following pics are of the discs fitted to the stub axle, and maybe thinking that the distance between the backing plate and the disc is fairly wide but there is no real difference with wheel track. OK! FINALLY GOT THE PROJECT WHEEL ALIGNED! AND HERE ARE THE WHEEL TRACK MEASUREMENTS ON THE FRONT USING THE WHEELS OFF MY UTE ON BOTH CARS (1241MM AT THE BOTTOM OF THE WHEEL RIM), AND THE PROJECT (1243MM AT THE BOTTOM OF THE WHEEL RIM)AS YOU CAN SEE THERE IS ONLY A 2MM DIFFERENCE IN THE WHEEL TRACK, (PLEASE NOTE THE WHEELS OFF MY HAVE GREATER OFFSET SO THE WHEEL SITS OUT FURTHER ON THE CAR









I have purchased a MS112 Disc Brake Rear End, (found it Cheap for $70.00)The rear end is now in the Car and the brakes are really good! especially the hand brake, I am using a 4.1 ratio diff center from the MS112 series Crown, Changed it from the 3.9 cause I found it drove a lot better! like better starting off and cruising speed.It has now been fitted too my Project and with a few modifications the 4 wheel disc setup works really well.