rear disc brakes on 8 3/4

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Buschi340

Buschi340

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i know this has been asked 10 thousend times but sines i live in Germany and everything is twice that expensive i have no room for experiments. My first intention was to go with Jeep cheerokee but there a few things i don't like. the park brake in the drums for example.

i want it cheap.
I want it solid.
i want the park brake on the caliper.
i want brake pads and brake discs from a regular car means not from the supplier of the kit.

that makes several no's for wilwood.

what about the 500 USD kit from SSBC? or summit self named kit? SSBC pads are from Ford. The discs not.

any other good kit on the market?

regards,
Michael
 
Rear disc kit from dr diff. I believe it's from/based on a ford mustang cobra setup.
 
I like the SSBC kits. Never had any issues with them. Plus they have great tech support, just a phone call away. For the most part "Right Stuff" just copies someone else's kits, and I have a feeling it's all made offshore (China maybe, but I have no proof).
 
The Dr Diff kit is the best option for the buck on the market. Used it on a 64 Barracuda that gets road raced at very high speeds on a race track and it works fantastic.
 
i have small drums. Still from the Small bolt pattern. And they are worn out already. And before I buy all that drum stuff and redrill to big Bolt pattern or buy big drums I gues it is more efficiant to go with discs. Remember i live in Germany and all the US stuff is almost double the Price you pay ( see also customs, shipping ).
thats why i originally wanted to use the Jeep stuff. but too much too Change and tire moves a bit outwards if i remember right. I have Zero space in my wheel openings.

and yes, i expect a bit improvement also. I like modern stuff :)
 
I put the jeep brakes on a 8 1/4 and no problems at all, just had to open the center hole and modify the parking brake cables to fit, no real big deal. I did a build thread on it here. You will need 15" rims. Just my opinion.
 
I'm sure there are reliable sources for "very slightly used" car parts of all varieties available here. I've seen new parts of all descriptions taken out of the box, inadvertently smudged with a bit of grease while being looked at and used for various things, repackaged and shipped as used parts. O:)

I have Dr Diff's rear brakes on both my A-Body and E-Body. They are simple, effective and perform excellent. Best to get big bolt pattern while you are at it.
 
Dr. Diff makes great parts. I wouldn't mess with anything else myself. I don't have his rear disk kit yet, but I do have his 13" cobra style front disk kit. It's awesome. :thumbup:

Two things to note:

-As far as I know, most rear disk kits require LBP axles. That's not just a matter of the bolt pattern though, you can't re-drill your SBP axles and use them. The axle flange offset is different between LBP and SBP axles. It's why you can't use LBP drums on SBP axles or vice-versa, regardless of the bolt pattern you re-drill. I would ask Dr. Diff to be certain about his kit, but it's my understanding that LBP axles are required.

-Most of the kits require the use of "green" bearings. Ie, not the tapered stock type bearings. Dr. Diff's rear brake kits can be used with the stock style tapered bearings. Without trying to start another "tapered vs green bearings" fiasco, I'll just say that I prefer the stock style tapered bearings. If you don't mind, or are already running green bearings, it doesn't matter. But Dr. Diff's rear brake kit is one of only a couple that can be used with the stock tapered bearings.
 
for what it's worth new 10 x 1 3/4" drums are avail. and are cheap.
the original rear drums w/front discs is matched and works good.
...but modern new stuff if dialed in can be nice
 
ir3333 said:
for what it's worth new 10 x 1 3/4" drums are avail. and are cheap.
the original rear drums w/front discs is matched and works good.
...but modern new stuff if dialed in can be nice
Click to expand...

And for a DD, in Canada, those are waaaay more than adequate, cuz the P-valve will cut some 70% of the pressure to the rears anyhow. Shoot,10 x 1 would probably be enough, for a DD.Maybe even less.....
But if you're cruisin high-speed, well,I can't speak to that, cuz here the speed limit is mostly 100, occasionally 110KPH
 
72bluNblu said:
Dr. Diff makes great parts. I wouldn't mess with anything else myself. I don't have his rear disk kit yet, but I do have his 13" cobra style front disk kit. It's awesome. :thumbup:

Two things to note:

-As far as I know, most rear disk kits require LBP axles. That's not just a matter of the bolt pattern though, you can't re-drill your SBP axles and use them. The axle flange offset is different between LBP and SBP axles. It's why you can't use LBP drums on SBP axles or vice-versa, regardless of the bolt pattern you re-drill. I would ask Dr. Diff to be certain about his kit, but it's my understanding that LBP axles are required.

-Most of the kits require the use of "green" bearings. Ie, not the tapered stock type bearings. Dr. Diff's rear brake kits can be used with the stock style tapered bearings. Without trying to start another "tapered vs green bearings" fiasco, I'll just say that I prefer the stock style tapered bearings. If you don't mind, or are already running green bearings, it doesn't matter. But Dr. Diff's rear brake kit is one of only a couple that can be used with the stock tapered bearings.
Click to expand...

Dr Diff does make a kit for the small bolt pattern, I have a set from him on my 66 Cuda. He uses the Cobra caliper with a park brake and a modified Toyota rotor. Probably not his most popular set but he makes one and it works great on my car, lots of track days no problem. Great guy as well!
 
gold66cuda said:
Dr Diff does make a kit for the small bolt pattern, I have a set from him on my 66 Cuda. He uses the Cobra caliper with a park brake and a modified Toyota rotor. Probably not his most popular set but he makes one and it works great on my car, lots of track days no problem. Great guy as well!
Click to expand...

Well there you go! Cass is great. Beyond just providing great parts, he's even helped me out a couple times when I had questions with an install. Knowledgeable dude.

As far as the old drums go, sure, they work. For the most part drums are plenty adequate. But there are a couple of situations they don't handle well. Water, for one. But that's pretty minor. The second is heat soak. Drums don't dissipate heat as fast as disks. So, if you're braking from high speeds, or braking frequently, heat builds up and they don't work as well.

Now, the OP is in Germany. Don't they have some fancy freeway with no speed limit? If I were gonna go run around on the autobahn, the stock drums wouldn't be my first choice...
 
inertia said:
Autobahn.. "unrestricted" speed limit areas.. lol
Click to expand...
that is correct :D

You guys got me wrong. I HAVE big bolt Pattern. I re-drilled my old SBP drums to fit the new axles. Now i dont wanna do that again and require all parts for BBP drums. That is Fu***ing expensive. So why not spend the same Money and get disks?



Jeep discs for a 8 3/4 is not a simple bold on. It requires a spacer which makes machining necessary. Thats how i read here.... tell me that i am wrong and i am happy. Those i can get here from time to time..
 
For 5 on 4.5" pattern.... 94-96 Intrepid front rotors (may require slight machining to fit over axle flange), Speedway Motors brackets, Cadillac metric calipers with E-brake.....
 
I have the right stuff rear disc kit with parking brake. I got it as an open box deal on Amazon for just over $300 shipped and received in 2 days with prime
If it matters these work with 15" wheels according to there site
Installed it with BBP Yukon axles with green bearings and had the whole kit and axles in under an hour
The only thing I don't like about the kit is being able to get another set of discs in the future and which specific GM caliper it uses. Info that I can't find anywhere

*Set up has not been driven on as I am still assembling the car. Although I'm sure there will be no issues.
I need to weld the brake hose brackets on the rear(also can't decide to just get the dr diff offset spring kit and run a smaller spacer or not so I can weld all at once) and need to make or purchase new brake/fuel hard lines to do final install/plumbing

Overall I'm happy with them and can't wait to "brake" them in
 

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Buschi340 said:
You guys got me wrong. I HAVE big bolt Pattern. I re-drilled my old SBP drums to fit the new axles. Now i dont wanna do that again and require all parts for BBP drums. That is Fu***ing expensive. So why not spend the same Money and get disks?
Click to expand...

Sigh. Ok-

1. Small bolt pattern axles can only be used with small bolt pattern brakes. That's it. Even if you re-drill the stock axles to BBP, you still have to use SBP backing plates and SBP drums and re-drill them as well. The axle flange offset is unique to the A-body SBP axles, nothing else from the factory has that offset.

2. Big bolt pattern brakes can only be used with big bolt pattern axles. That means you can not use big bolt pattern rear drums and backing plates (10x2.5, 11x2, 11x2.5, or 11x3) with ANY stock A-body 8 3/4 axle, as they were all SBP from the factory.

You can't re-drill SBP drums to BBP and use them with regular BBP axles, the drums will not line up with the shoes. Re-drilled SBP drums must be used with re-drilled SBP axles.

If you have *most* aftermarket BBP axles, you must use BBP brakes. Not re-drilled SBP brakes, but brakes that were originally used with BBP axles. There are some aftermarket BBP axles that were available with the SBP axle flange offset, but those can only be used with re-drilled SBP brakes.

That's why it's important for the disk conversion. The bolt pattern itself isn't the problem, you can drill any pattern you want. It's the offset of the axle flange that matters, and BBP axles and SBP axles had different axle flange offsets from the factory. For the disk conversion, the caliper must be centered over the rotor. The rotor will be in a different place with a BBP axle compared to a SBP axle, so you must use a kit that was intended for your axle flange offset. Sounds like Dr. Diff makes kits for either style, but you have to know what you have. A redrilled SBP axle is not the same as a BBP axle, even if the bolt pattern was changed to be the same.

This is the problem...
attachment.php
 
72bluNblu ,
very good Point. Didn't know about that off set. but can't be that much. It is working this way since 3 years. But you are right. I saw that the linings are not centered in the drums. One reason more to Change it to discs. :)
ok, got yukon BBP axles and green bearings already.

mguner,
you did that swap? Parts list, sources etc?

74DartSwinger360,
did you ask right stuff where to buy pads and discs?
 
Buschi340 said:
72bluNblu ,
very good Point. Didn't know about that off set. but can't be that much. It is working this way since 3 years. But you are right. I saw that the linings are not centered in the drums. One reason more to Change it to discs. :)
ok, got yukon BBP axles and green bearings already.
Click to expand...

Well, Yukon is one of the aftermarket suppliers that makes BBP axles with a SBP flange offset. So, it's possible that your BBP axles have a SBP flange offset, which means you would need a disk kit intended for SBP axles but drilled with the big bolt pattern.

The offset isn't much, pretty much just the thickness of the axle flange, but it's more than enough to cause problems. For example, if you use stock BBP drums on a redrilled SBP axle, the drums hit the backing plates and cause interference. That's a no go. If you use redrilled SBP brakes on BBP axles, the drums don't cover the brake linings completely, rendering them significantly less effective than stock. If your brake wear pattern goes all the way out past the edge of your drums, that's probably what you did. Your brake shoes would have a "lip" on them near the backing plate as well.

In either case, you'll need to know which flange offset you have before you buy a disk kit. If your kit isn't intended for the axle flange offset you have, the rotors won't line up with the calipers.
 
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