Drum/Drum Reaction Arm Kit install issues Help needed

J

JHeslinga

Member
Feb 9, 2011
619
0
16
Hi All

I'm currently installing a Tom Pryor Drum/Drum Reaction arm kit and having some issues that I believe are design related and looking for advise from
members that have experiencing installing this kit themselves. Firstly I a bit disappointed that the kit was missing some of the installation tools
and supplies that are indicated as being part of the kit. OK I was able to acquire what I needed but why? The Next problem is that the instructions
illustrations do not match well the actual parts of the kit.

The trunion bearing on the rear of the torque box illustrations or instructions simply show a round plate but the actual plate has a flange. The
instructions show to install the torque box plates on the trunion, But that would mean that the flange actually increases the space between the plates
and they will not bolt up. If put the trunion after the box (With the Fl;ange on the outside then it seems to fit better so I'm not sure Im right
but I hope so.

The real problem right now is that when I need to install the backing plate on the torsion box it WILL NOT seat. The lower two bolts of the lower
spacer plates are too high on the torque box!!?? They interfere with the flange of the backing plate??!! They should neatly protrude into the
indentation of the backing plate so there would be no problem. The bolts should be at least 1/2 inch or more lower on the torsion box ( The Box
should be longer by that much too!!!)

In order to allow the nuts, Lock washers and bolts to fit I experimented with drilling large holes in the backing plates as a relief for the fasteners
and it seems to work at the moment BUT Why do I have to re-engineer this thing?? I have photos in a personal photo album to more clearly describe
my problem. its at:

http://www.gmcmhphotos.com/photos/g7235-drum-brake-reaction-kit.html

If you have installed one of these kits, What did you do to accomplish this task without the re-engineering of the plate? Do you have any advise I
need that I seem to be missing? There are another couple of issues that concern me and that is that it does not rotate and use the spindle as a
means of centering the backing plate in the drum. Normally the backing plate is positioned centered on the spindle, It certainly seems to "Float"
Way to much for my liking. I haven't been able to get it finished enough to actually see how it works but I'm Concerned.

All help will be appreciated.

John
--
John and Cathie Heslinga
1974 Canyonlands 260
455, Manny tranny and 1 ton, 3:70 LS,
Red Seal Journeyman, DTE, BEd. MEd.
Edmonton, Alberta
 
John,

I have put a call in to Tom to apprise him of your situation. I left messages on both his phones. He lives in Florida and may call you too early.

Mine is a Mk1-B model, and it is in place for lots of years now so some assembly is only a memory, but I think we put the bolts through the torque box
the other way. I do still have the documentation, but it is in the coach in the barn and it will be a while before I put cloths on.

With the torque box home, the backing plate should be free to move and not much more. It looks to me like you are missing the plastic bearing that
goes between the spindle and the outside plate of the torque box. When that bearing is in place, the backing plate should not be sloppy at all.
There should be two of those (they aren't Delrin, but like it) ring bearings per torque box. The backing plate is real tight when they are there. -
At least in mine.

Matt
--
Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan
OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit
 
First call Tom, and show him those pictures. I've put that kit on two coaches without problems or having to drill anything. It looks from the
pictures as though you have the torque box reversed. The only physically hard part of the install is countersinking the spindle bolts. What you have
needs to come off and be rethought, hopefully with Tom on the phone. Too far from here to come lay hands on it. One concern - the kits are slightly
different depending whether the rear has been converted to disc. Make sure you haven't got a disc kit by accident.

--johnny
--
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
 
Sir: here are pics of my first install. The bolts are put in from backing plate side. My bearing spacers were different as I also installed the
rear bearing greaser kit which had its own issues. As for the flange on the plastic bearing, you may have a kit for disc brake? It has been a while
and my memory is not good. It seems the kit I put on LaBraun's coach was shipped with the wrong size counter sink bit, wrong pivot bushings, and
ended up being for a disc brake set up. I was very disappointed with the lack of quality control as some of the bolt holes would not line up in the
pivot box and had to be egged shaped and some pivot boxes were made of different thickness steel material. I would also advise talking to Tom.

http://www.gmcmhphotos.com/photos/drum-brake-reaction-arm-system/p49348-parts.html

http://www.gmcmhphotos.com/photos/g6386-rear-wheel-bearing-greasers.html

> Hi All
>
> I'm currently installing a Tom Pryor Drum/Drum Reaction arm kit and having some issues that I believe are design related and looking for advise
> from members that have experiencing installing this kit themselves. Firstly I a bit disappointed that the kit was missing some of the installation
> tools and supplies that are indicated as being part of the kit. OK I was able to acquire what I needed but why? The Next problem is that the
> instructions illustrations do not match well the actual parts of the kit.
>
> The trunion bearing on the rear of the torque box illustrations or instructions simply show a round plate but the actual plate has a flange. The
> instructions show to install the torque box plates on the trunion, But that would mean that the flange actually increases the space between the
> plates and they will not bolt up. If put the trunion after the box (With the Fl;ange on the outside then it seems to fit better so I'm not sure Im
> right but I hope so.
>
> The real problem right now is that when I need to install the backing plate on the torsion box it WILL NOT seat. The lower two bolts of the
> lower spacer plates are too high on the torque box!!?? They interfere with the flange of the backing plate??!! They should neatly protrude into
> the indentation of the backing plate so there would be no problem. The bolts should be at least 1/2 inch or more lower on the torsion box ( The
> Box should be longer by that much too!!!)
>
> In order to allow the nuts, Lock washers and bolts to fit I experimented with drilling large holes in the backing plates as a relief for the
> fasteners and it seems to work at the moment BUT Why do I have to re-engineer this thing?? I have photos in a personal photo album to more
> clearly describe my problem. its at:
>
> http://www.gmcmhphotos.com/photos/g7235-drum-brake-reaction-kit.html
>
> If you have installed one of these kits, What did you do to accomplish this task without the re-engineering of the plate? Do you have any
> advise I need that I seem to be missing? There are another couple of issues that concern me and that is that it does not rotate and use the
> spindle as a means of centering the backing plate in the drum. Normally the backing plate is positioned centered on the spindle, It certainly
> seems to "Float" Way to much for my liking. I haven't been able to get it finished enough to actually see how it works but I'm Concerned.
>
> All help will be appreciated.
>
> John

--
C. Boyd
76 Crestmont
East Tennessee
 
Sir: it appears from your pics that the torque box on your kit has the bolt holes drilled thru with washers and nuts. Mine had the spacer block
drilled and tapped for short bolts with lock washers, ( and some of the holes were not tapped and would not line up.). Yours don't even look like the
other ones I have installed that had mitered joints on the spacer blocks. Even after the full week of install hassles and re- engineering I was
impressed with the results. After I got everstuff to fit with correct tolerances the brakes worked much better. It changed the braking effect from
pole vaulting to squat and stop. Overall braking improved at least 30% across the board. I do recommend the kits but don't ask me to put it on.

> Sir: here are pics of my first install. The bolts are put in from backing plate side. My bearing spacers were different as I also installed the
> rear bearing greaser kit which had its own issues. As for the flange on the plastic bearing, you may have a kit for disc brake? It has been a
> while and my memory is not good. It seems the kit I put on LaBraun's coach was shipped with the wrong size counter sink bit, wrong pivot bushings,
> and ended up being for a disc brake set up. I was very disappointed with the lack of quality control as some of the bolt holes would not line up in
> the pivot box and had to be egged shaped and some pivot boxes were made of different thickness steel material. I would also advise talking to Tom.
>
> http://www.gmcmhphotos.com/photos/drum-brake-reaction-arm-system/p49348-parts.html
>
> http://www.gmcmhphotos.com/photos/g6386-rear-wheel-bearing-greasers.html
>
>
>
>
>
>
>
>

> > Hi All
> >
> > I'm currently installing a Tom Pryor Drum/Drum Reaction arm kit and having some issues that I believe are design related and looking for
> > advise from members that have experiencing installing this kit themselves. Firstly I a bit disappointed that the kit was missing some of the
> > installation tools and supplies that are indicated as being part of the kit. OK I was able to acquire what I needed but why? The Next problem
> > is that the instructions illustrations do not match well the actual parts of the kit.
> >
> > The trunion bearing on the rear of the torque box illustrations or instructions simply show a round plate but the actual plate has a flange.
> > The instructions show to install the torque box plates on the trunion, But that would mean that the flange actually increases the space between
> > the plates and they will not bolt up. If put the trunion after the box (With the Fl;ange on the outside then it seems to fit better so I'm not
> > sure Im right but I hope so.
> >
> > The real problem right now is that when I need to install the backing plate on the torsion box it WILL NOT seat. The lower two bolts of the
> > lower spacer plates are too high on the torque box!!?? They interfere with the flange of the backing plate??!! They should neatly protrude
> > into the indentation of the backing plate so there would be no problem. The bolts should be at least 1/2 inch or more lower on the torsion box (
> > The Box should be longer by that much too!!!)
> >
> > In order to allow the nuts, Lock washers and bolts to fit I experimented with drilling large holes in the backing plates as a relief for the
> > fasteners and it seems to work at the moment BUT Why do I have to re-engineer this thing?? I have photos in a personal photo album to more
> > clearly describe my problem. its at:
> >
> > http://www.gmcmhphotos.com/photos/g7235-drum-brake-reaction-kit.html
> >
> > If you have installed one of these kits, What did you do to accomplish this task without the re-engineering of the plate? Do you have any
> > advise I need that I seem to be missing? There are another couple of issues that concern me and that is that it does not rotate and use the
> > spindle as a means of centering the backing plate in the drum. Normally the backing plate is positioned centered on the spindle, It certainly
> > seems to "Float" Way to much for my liking. I haven't been able to get it finished enough to actually see how it works but I'm Concerned.
> >
> > All help will be appreciated.
> >
> > John

--
C. Boyd
76 Crestmont
East Tennessee
 
I've never installed or checked out these systems, but a picture is the only tool necessary sometimes. Chuck nailed it with his first post before I
got back to the forum: Put the bolts in from the other direction 8)
--
Terry Kelpien

ASE Master Technician

73 Glacier 260

Smithfield, Va.
 
You must log in or register to reply here.
Applied GMC
GMCMI Fall 2026 Rally

Share this page

Share this page
Top Bottom
Back