Rear wheel studs

[Phil S]

Hi All,
has anybody fitted the Monarch rear disc set up, when they were available, or has made up therein own set up, as I am currently doing.
if so the question is, Do you need longer rear wheel studs to accommodate the thickness of the disc.

many thanks Phil

[bullstarz]

You also got to think of how you got a mount the caliper onto the truck semitrailing arm. You’ll have to fit longer studs on the training on, to accommodate the bracket that holds the caliper.
I did my own a few years ago and designed my own bracket. I’ll still have the CAD file somewhere. There’s quite a few threads on this website and others showing how to do it. C925935F-96DD-466F-88DB-24E9464EE87C.jpeg

[NeilR]

I did my own disc conversion.
The thickness of the centre of the disc (Honda Accord / Rover 600) that fits on the hub is not much thicker than the drum.
So longer studs not needed for me.

My caliper brackets, were made from 8mm steel, machined down to 5mm for the centre bit that fits on the trailing arm,
(not much thicker than the drum backplate), so the standard trailing arm studs were long enough.

Neil.

[mike@thenook]

One thing you need to be careful of Phil is to not allow the width of the disc to affect the offset of the wheels as with the 7" set up - there would be problems if anything thicker pushed the wheel further out

[stag8manod]

I would suggest when doing this conversion to use the opportunity to increase the trailing arrn studs to 3/8 UNC if not already done. I did mine when I installed a pair of CCD CV half shafts.
Cheers Ian A

[Phil S]

thanks Neil,
the ones I am getting are 10mm ally, but was thinking of making some 5mm ones, originally so may still go that way.
I have the discs and callipers ready to go.
Phil

[Phil S]

Ian
faversham fitted ccd shafts and hubs 3 years ago when I first got the car so don't know if the studs were replaced. Will find out when its pulled apart.
Phil

[new to this]

Phil

When i did mine,i didnt have to change the rear studs they were long enough

[stag8manod]

It's not the length of studs. Its the fact the factory used 5/16 UNF threads in the aluminum trailing arms, an Engineering NONO. Under high stress they can pull out, I've seen it happen. not pretty. They need to be 3/8 UNC and Loctited. Consider, high speed cornering and the load generated with the small fine thread studs threaded into a soft base material. I can't believe Triumph did it.
Cheers Ian A

[new to this]

It's not the length of studs. Its the fact the factory used 5/16 UNF threads in the aluminum trailing arms, an Engineering NONO. Under high stress they can pull out, I've seen it happen. not pretty. They need to be 3/8 UNC and Loctited. Consider, high speed cornering and the load generated with the small fine thread studs threaded into a soft base material. I can't believe Triumph did it.
Cheers Ian A

have already upgraded the trailing arm studs

[Motorsport Micky]

The studs are in shear, and although only held by a paltry 16 lb ft because there are 6 of them on each hub they will not fail in use as long as the threads are the correct ones, which in my opinion is UNC.
The position of the alloy blocks positioned around the hub housing on the trailing arm when the arm was cast is critical and unfortunately entrusted to a YTS who had only been on the job 3 months...and he turned in drunk ! They are "variable" in positioning and I've seen numerous stud holes where the threads are nearly breaking through the casting wall, if you try and reclaim an arm with stripped holes it's not unusual to break through the wall thickness. The normal Helicoil fitment tries and put a 5/16th UNF internal threaded hole with a Helicoil coarse outer thread into the same position, the drilling dia for the helicoil tap is .328 thou which is counter intuitively16 thou more than the hole dia required for tapping 3/8th UNC set at .312 thou, our old friend 5/16 th of an inch the original outside tapped hole in the trailing arm. When the hole is stripped out by the stud it doesn't even need drilling, just tap the hole 3/8 UNC and fit hybrid 3/8th x 5/16th studs.
Oh...and the holes in the hubs are about a 5 thou clearance on the studs, if you hand drill and tap into the trailing arm you'll find it very difficult to get them square in the two planes required and you'll end up leaning studs and be unable to get the hub over them, which means you'll end up opening the holes out, which means the studs then have a bending motion put on them...use a jig to keep drills and taps square and do a good job.

Micky

[stag8manod]

Hi Mickey, When I did mine I intended to Heli-coil as well but found there wasn't enough ally in the arm to hold them. To ensure the new tapped holes were square and true I made a set of drilling jigs which worked well and the new CCD hubs tapped on as they should.
Cheers Ian A

[trunt]

This is on my winter Radar,

Is there a description of the type of jig needed anywhere? I remember some company that rents one out but being in USA that’s probably out.

I wondered if an old hub or drum could be used by using spacers to hold it out on the end of the existing studs, (maybe even use extra long studs) then drill and tap through one hole? Maybe need to open up that hole for clearance?

Terry

[trunt]

Ha!
amazing what a quick google will uncover..

http://www.pattonmachine.com/TAK.htm

a USA supplier of the jig..

[trunt]

OK so I am having trouble sourcing the 3/8 x 5/16 studs..

I found them at CDD but anywhere else?