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Salisbury rear disc brake conversion merged threadfest

59K views 291 replies 55 participants last post by  Ephry73 
#1 · (Edited)
Woohoo! I did the rear drum to disc brake conversion this weekend, using all land rover parts, and am very excited about the outcome. Thank to Keith at Rovertracks for all his guidance.

There is no instructions on this, as it requires a mix of Defender 90, Disco I and RRC parts, so if anyone has questions, you can refer to Keith or I if your interested.

Few top roadblocks/lessons learned:

1) not all Type 37 bearings are the same. I bought a full set of replacement bearings from NAPA, to replace what I had as generally preventive measure, and not a single one of them would fit on my rear spindles, despite the fact that they had the same ID as the US made Timkens that were already in there (which would comfortably slide on and off the spindles). I will never buy anything but Land Rover and/or Timken bearings again.

2) Make sure I have all the parts up front, to include bolts. I had forgotten to order the bolts that mount the rotors to the hub. Those bolts, as well as the member to hub bolts are all hardened grade 10 quality M10 x 1.50. With the first axle completely apart, I had to run all over the place to find an equivalent. Home Depot, Lowes, Ace Hardware and NAPA don't stock M10 x 1.50 in grade 10 equivalent. I had to use grade 8 temporarily to get by. Don't be me.

3) Get a tap and die for M10 x 1.50 and keep it as part of the standard tool kit. Just about every bolt/nut/thread on the salisbury is that size/thread combo. I was installing a used RRC hub (varies from the 110 hub in that it has the threaded holes for the rotor) and the drive member holes were crudded. I ended up overtorqueing a bolt and snapping it off. What a PITA that was. After hours of attempting to drill out the bolt remains (and breaking multiple drill bits in process), I gave up. Running 4 bolts and tracking down a new hub. I quickly bought a metric tap and die set that night. Next morning taped and the holes on the other hub to clean them up and freshen the threads, and did the same to all the drive member bolts. Went together like a charm.

New brake system works great. My drum pads clunked because they were so worn, and now my brakes are nice, tight and quiet. I love that the new calipers have the drop in pads, making the next change quick and easy.

Thanks Keith! You da man.
 
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#8 ·
The brackets are the only part that needs to be modified. They have to be milled per Keith. It was my intention to do a build thread, and I was going to take pictures of the right side (after I had the learning curve down from the left side), but the broken bolt set me back a few hours out of my alotted project time, so I had to scramble to get it done.

Now that I know what the hell I'm doing, when I get my replacement hub, and tear down the left side again, I'll post pics and note instructions on that rebuild. I still have the old drum parts to illustrate with.

As for stopping power, I didn't do it for additional stopping power. I learned long ago when researching this, per ECR in a dated thread on the subject, that a disc conversion in the rear won't improve stopping power; only vented discs up front will do that (another conversion down the road, but much easier). And to be honest, when the drum pads are new and adjusted right, that's all the stopping power for me. I did this conversion because the drums suck at maintenance, and when they are wet/muddy. Disc are so much easier to maintain.

The pads are only a day old, so still setting in. Maybe I'll see a slight improvement after 100 miles or so.
 
#11 · (Edited)
landrovered said:
I am not looking for shorter stopping I just want to get rid of the drum adjustment and have a consistant pedal.
Then this conversion is for you!

Follow-up Post:

Here is the quicklist of parts needed from Keith, plus all the implied. I'll have to get part#'s later.


REAR:
  1. 2x Caliper brackets (FTC 3306) and have them machined .100" on the caliper mounting side
  2. 2x Non ABS RRC hubs front or rear (they are same) The only difference with 93' 110 hubs is the thread holes for the rotor to mount to
  3. 2x Rear RRC/D1 rotors (non-vented)
  4. Disco/D90 Calipers
  5. Disco/D90 rear pads
  6. 4x caliper bolts from a Disco or D90(hardware store grade 10.9 is fine).
  7. Full seal set (or for wet hubs, just the double lip Inner hub seal:rtc3511
    )
  8. Brake kit for rotors with 4x split pins and 4x anti-rattle springs
  9. 10x rotor mounting bolts
  10. left and right 110 rear disc brake stone shields (they mount right to the bracket)
  11. 4x M8 (I believe) nuts with washer and lock washer to mount stone shields to bracket
  12. 2x spindle lock washer (same as what you have already on the 93')
Things you can keep from the original drum/hub assembly
  1. Drive members
  2. Inner and outer race and bearings (if they are in good condition, just drift them out and install in new hub)
  3. Drive member bolts
  4. inner axle spacer
  5. axle retaining c-clip
  6. stub axle mounting bolts (2 each side are reinstalled with their nyloc nuts, and the other 4 each side mount directly through the stub flange into the caliper bracket.
Make sure to flip-off your drums when you pull them off. I got great satisfaction out of that.
 
#14 ·
Overlander said:
The brackets are the only part that needs to be modified. They have to be milled per Keith. It was my intention to do a build thread, and I was going to take pictures of the right side (after I had the learning curve down from the left side), but the broken bolt set me back a few hours out of my alotted project time, so I had to scramble to get it done.

Now that I know what the hell I'm doing, when I get my replacement hub, and tear down the left side again, I'll post pics and note instructions on that rebuild. I still have the old drum parts to illustrate with.

As for stopping power, I didn't do it for additional stopping power. I learned long ago when researching this, per ECR in a dated thread on the subject, that a disc conversion in the rear won't improve stopping power; only vented discs up front will do that (another conversion down the road, but much easier). And to be honest, when the drum pads are new and adjusted right, that's all the stopping power for me. I did this conversion because the drums suck at maintenance, and when they are wet/muddy. Disc are so much easier to maintain.

The pads are only a day old, so still setting in. Maybe I'll see a slight improvement after 100 miles or so.
I already did the front vented conversion and still have a long pedal stroke and mushy feel (brakes have been bled recently). My hope was that the rear shoes were worn and way out of adjustment, that does seem to be the case. If this doesn't sort things out I'll start further investigation.
 
#15 ·
I have a pulsating pedal that feels very non-confidence inspiring. I found a badly rusted brake line and hoped that would fix it. It didn't. Maybe I'll find another bad line, but I really just want to do this for the heck of it, especially since I've got the calipers just sitting around.
 
#16 ·
Johnathan,
After my first day driving, I found my pedal stroke extremely short, very little pressure needed for full stop. The whole system feels very "tight' for lack of a better word. Before that, I had a long stroke with a clunk from the slack in my drums.

Jim,
as for you pulsation, I just replaced my wife's disco's rotors and pads, as a pulsation can only mean one thing..a warped rotor. After I swapped them out, problem gone.
 
#20 ·
Just a thought but at the shop I used to work at, we had more than several brand new rotors that where warped out of the box, it may be worth going down and having them turned as they are new and little materal would need to be removed, unless they are really bad. But as soon as they go on the machine they will be able to tell you how bad they are out.
 
#25 · (Edited)
During the conversion with my head in the wheelwell, the logic behind the machining became clear to me. It is not evident as you install the bracket onto the axle/stub assembly, but as I was installing the caliper onto the bracket, with the rotor already in place, you can clearly see how the machining can vary the position of the rotor within the squared out channel in the caliper. Ideally, you would want the rotor perfectly centered as it passes through the caliper (look at the rotor from the long end, and you will see a squared out channel that runs the length of it..kind of like the photon torpedo run by Luke Skywalker on the death star attack. The rotor being Luke's Xwing fighter). If your machining is off, the rotor won't be centered, and might rub on either side of that channel. Mine rubbed on one side just a tad bit on the outside, just enough to make a little knows when the rotor spins by hand. That will wear quickly as it is minor. If the machining had been a little higher, it would have been more towards center, and enough to pull the rotor farther away from the outside channel. My guess is it can really vary due to minor variations in the parts involved (axle, rotor, caliper,caliper bracket). I would take Keith's advice, as if you went .100, and it rubs slightly, you can take more off incrementally. If you go .140, and it is rubbing on the inside...then your talking spacers or new bracket.

I will take pictures to illustrate this when my replacement hub comes in, since I have to swap my right rear hub out due to the broken bolt.
 
#26 ·
I'm going to pull the entire axle to do this, so it will be easier to take pix. My stuff is so ugly that it needs a good blast and paint.

I also plan to put the vented rotors on the front - does anyone know if the front rotors can just be moved to the back?
 
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