Moparts
DoctorDiff's rear disc kit
Posted By: AndyF
DoctorDiff's rear disc kit - 08/25/10 07:52 AM
I shot a couple of pictures while I had the car up on jacks the other day. This is a really nice disc brake setup that Cass had engineered for the Mopar rear ends. This setup keeps the tapered roller bearings rather than forcing you to switch to the green bearings. It also uses an OEM quality caliper with weather seals and e-brake. Nice setup that is fairly compact and lighweight.
Posted By: AndyF
Re: DoctorDiff's rear disc kit - 08/25/10 07:55 AM
Another view, this time without the rotor in the way. The aluminum bracket on this kit is a nice CNC machined part.
Posted By: moparniac
Re: DoctorDiff's rear disc kit - 08/25/10 12:19 PM
I run that kit on my dart! Only difference is I grinded off the ford logo!
Posted By: topbrent
Re: DoctorDiff's rear disc kit - 08/25/10 12:42 PM
Which DrDiff rear disk kit is that?
- The caliper brackets shown in your pics look like a 1 piece billet design.
Just curious, as we just purchased the 10.7 rear disk kit from Cass, and it uses a powder coated 2 piece caliper bracket setup.
Posted By: MR_P_BODY
Re: DoctorDiff's rear disc kit - 08/25/10 01:22 PM
Andy what is that arm on the turnbuckle ... I dont
know what I'm seeing
Posted By: all spooled up
Re: DoctorDiff's rear disc kit - 08/25/10 01:47 PM
Quote:
Andy what is that arm on the turnbuckle ... I dont
know what I'm seeing
sway bar link ???????????
Posted By: racealittle
Re: DoctorDiff's rear disc kit - 08/25/10 01:53 PM
Quote:
I shot a couple of pictures while I had the car up on jacks the other day. This is a really nice disc brake setup that Cass had engineered for the Mopar rear ends. This setup keeps the tapered roller bearings rather than forcing you to switch to the green bearings. It also uses an OEM quality caliper with weather seals and e-brake. Nice setup that is fairly compact and lighweight.
I studied the Fine Lines kit a friend bought that requires the green bearings. I don't see why they say green bearings are required. The Fine Lines kit won't work with factory rally rims, I hear that the kit Cass offers will.
The Dr. Diff kit looks very nice in comparison, which may justify the price difference for some.
Posted By: blown572dart
Re: DoctorDiff's rear disc kit - 08/25/10 02:27 PM
Do they work on a rear with grean bearings?
Posted By: DoctorDiff
Re: DoctorDiff's rear disc kit - 08/25/10 03:37 PM
My rear disc brake kits work with OEM adjustable A-7 bearings, 3.15" A-20 tapered bearings, MO-400 Green bearings, ST-400 Green bearings and RP-400 Green bearings.
I have 3 versions with different rotor sizes: 13", 11.7" and 10.7".
The most popular size is 10.7" (pictured) which fits most 15" wheels.
Most 10.7" kits I sell come with a bolt-together steel caliper bracket because the high-offset aluminum version is cost prohibitive.
The 11.7" and 13" versions come with billet aluminum caliper brackets because the offset is much shallower.
Drilled/slotted/plated rotors are optional on all kits.
Posted By: AndyF
Re: DoctorDiff's rear disc kit - 08/25/10 03:52 PM
Quote:
Andy what is that arm on the turnbuckle ... I dont
know what I'm seeing
Adjustable rear anti-sway bar. This is a road race car, not a drag racer.
DoctorDiff's rear disc kit now has been approved at 150 mph!
Posted By: Jerry
Re: DoctorDiff's rear disc kit - 08/25/10 04:15 PM
Can you run the 13" kit under a 17" wheel or do you need 18s?
Posted By: DoctorDiff
Re: DoctorDiff's rear disc kit - 08/25/10 04:26 PM
Most 17" wheels will clear my 13" rear kit. This kit is usually paired with 14" or larger front rotors, which won't fit 17" wheels, however.
Posted By: MIKES_DUSTER
Re: DoctorDiff's rear disc kit - 08/25/10 04:32 PM
Do you have a front disk brake kit and if so,whats the cost of it?? I still run drum brakes all around on my 72 duster.
Posted By: roadrunninMark
Re: DoctorDiff's rear disc kit - 08/27/10 06:30 PM
Another
for the doc diff rear kit. I had some questions as well and he was always happy to answer them. Here is a shot of mine installed:
Mark
Posted By: DoctorDiff
Re: DoctorDiff's rear disc kit - 08/27/10 09:45 PM
I also make 11.7" and 13" rear kits as well as matching front disc brake kits with 11.75", 13" and 14.25" rotors.
Posted By: jbc426
Re: DoctorDiff's rear disc kit - 08/27/10 11:11 PM
I love my Dr Diff disc brakes! The combination of parts he recommended on my '68 A-body give nearly perfect balance and modulation. They have saved my bacon a few times in critical finess braking situations. The price is right too!
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Posted By: DemonDust
Re: DoctorDiff's rear disc kit - 08/28/10 12:43 AM
These look great.
Can I ask a dumb question??? Well I'm gonna......
If you don't have green bearings and they are required for a brake setup, what can happen? What do you gain? Lose?
Thanks in advance
Posted By: dakster
Re: DoctorDiff's rear disc kit - 08/28/10 01:11 AM
How much width do these rotors add to the rear end, how thick on the rotor hat?
Posted By: DoctorDiff
Re: DoctorDiff's rear disc kit - 08/28/10 01:59 AM
You can use Green bearings or OEM, A7 tapered wheel bearings with any of my rear kits. Green bearings are not required.
The rotors are .250" thick. This adds 0.125" per side to the original assembly width.
Posted By: Pale_Roader
Re: DoctorDiff's rear disc kit - 08/31/10 03:38 PM
Quote:
I shot a couple of pictures while I had the car up on jacks the other day. This is a really nice disc brake setup that Cass had engineered for the Mopar rear ends. This setup keeps the tapered roller bearings rather than forcing you to switch to the green bearings. It also uses an OEM quality caliper with weather seals and e-brake. Nice setup that is fairly compact and lighweight.
So this pic is ov a road race car? What size are those rotors in the picture?
Can i assume that the 11.7" rears will fit under stock 15" steel rims? 15x8" Ramcharger rims? How would a 3200lb E-body brake with 11.75/11.7" discs all 'round...???
I've been thinking about this idea for a long time for my 70 Challenger. Last time i checked (long ago) i thought it was AndyF making conversion brakes for Mopars, but now i see his car with Dr. Diff's brakes... Hmmm...
Would the 11.7" rear set-up be lighter than a drum brake set-up?
Posted By: AndyF
Re: DoctorDiff's rear disc kit - 08/31/10 03:49 PM
Yes, it is a road race car. Those are 10.7 brakes in the picture and they work just fine on a car that goes 150+ mph. The car could probably use more rear brake so we might step it up to the larger rotors.
Posted By: Pale_Roader
Re: DoctorDiff's rear disc kit - 08/31/10 03:57 PM
Quote:
Yes, it is a road race car. Those are 10.7 brakes in the picture and they work just fine on a car that goes 150+ mph. The car could probably use more rear brake so we might step it up to the larger rotors.
So on a 3200lb E-body with really wide (good) tires the 11.75/11.7" brakes all around would work pretty well at speed...???
Sure wish i could fit the really big stuff under stock rims... I'd like the option ov throwing the stock rims on for a nostalgia night now and then...
Posted By: AndyF
Re: DoctorDiff's rear disc kit - 08/31/10 05:49 PM
Just depends how much power you have and how hard you drive. A powerful 3200 lb car that is being driven hard on a road race course will cook the factory 11.75 rotors really quick. If you're just cruising around the track then they'll last a long time.
We use a custom built 13 x 1.250 rotor up front on this Valiant with Baer six piston calipers. Those are $3000 brakes and even those will start to fade after repeated stops from 150. Factory 11.75 rotors up front would be toast in a few laps on a car like this.
Posted By: Pale_Roader
Re: DoctorDiff's rear disc kit - 09/01/10 11:21 AM
Quote:
Just depends how much power you have and how hard you drive. A powerful 3200 lb car that is being driven hard on a road race course will cook the factory 11.75 rotors really quick. If you're just cruising around the track then they'll last a long time.
We use a custom built 13 x 1.250 rotor up front on this Valiant with Baer six piston calipers. Those are $3000 brakes and even those will start to fade after repeated stops from 150. Factory 11.75 rotors up front would be toast in a few laps on a car like this.
You know, i drive my cars pretty hard. Actually no, i should say i drive them pretty fast, all the time, everywhere, but somehow i am just not hard on the brakes. I get crazy mileage out ov brakes compared to others. Even on the girlfriend's 96GT Mustang, with its 4-wheel (but very small) discs, i've only warped two sets (fronts) in 4 years, and those stock GT (not the Cobra brakes) will warp if you look at 'em hard enough...
I've got a couple cars i've owned for years and years that still have the brakes on them they came with. Sure, road racing will change the needs drastically, but i still say i'd do better than most, wear-wise. Again, the ONLY reason i wont go with bigger 13 or 14" set-ups, is so i can still use stock rims on occasion.
I'm assuming you're doing all the usual tricks with your Valiant like cooling/ducting, SS hoses, etc....??? I haven't gone that far yet, but i will with this project i'm building.
Posted By: AndyF
Re: DoctorDiff's rear disc kit - 09/05/10 06:46 AM
Cass, is the Ford Explorer kit still available? Looks like it isn't in the catalog anymore. There is a replacement kit that has a bigger 11.8 rotor and doesn't look the same. The Explorer kit used a drum parking brake and the new M-2300-G2 kit looks like it uses the caliper for the parking brake. Have you used the new kit?
Posted By: topbrent
Re: DoctorDiff's rear disc kit - 09/05/10 07:08 AM
Quote:
AndyF:
Cass, is the Ford Explorer kit still available? Looks like it isn't in the catalog anymore. Have you used the new kit?
What catalog?
Posted By: mikoto
Re: DoctorDiff's rear disc kit - 10/02/10 01:52 AM
Quote:
Quote:
Yes, it is a road race car. Those are 10.7 brakes in the picture and they work just fine on a car that goes 150+ mph. The car could probably use more rear brake so we might step it up to the larger rotors.
So on a 3200lb E-body with really wide (good) tires the 11.75/11.7" brakes all around would work pretty well at speed...???
Sure wish i could fit the really big stuff under stock rims... I'd like the option ov throwing the stock rims on for a nostalgia night now and then...
Hi, good day.
there's just had happened to my car and ohh, i just had realized that to increase the boost of my ford i need to fix the engine i mean i need to adjust the settings. from my ford parts. ha ha ha
cheer up!
mikoto | miyata 
Posted By: ThermoQuad
Re: DoctorDiff's rear disc kit - 10/02/10 11:16 AM
Alright enough of scaring the kids
Stock rotors hold up under road course conditions at least for me...ok so I only go 130 mph with a old muscle car...I think that is plenty fast. The pads typically give out long before the rotors throw in the towel. I use the wilwood calipers/11.75 rotors with a different pad material that holds up very well under duress[long wearing] and the car stops well without much fade ever. There are air ducts on the rotors as well. I have many miles on this set up, it works, the rotors are wearing nicely and are not warped...I ran for years with the stock stock two piece rotor/calipers with carbon metallic pads, no problems with the rotors, just some fade and poor pad life. [hint it's in the bearing preload]
On another car I have one of Doc Diffs rear wheel disc brakes kits in use and it is a nice set up. We needed a different mounting bracket to clear the firm feel sway bar and Doc Diff came thru with the fix!!!
Posted By: gsmopar
Re: DoctorDiff's rear disc kit - 10/02/10 05:58 PM
No issue with mine. They work great!
Posted By: deaks
Re: DoctorDiff's rear disc kit - 10/02/10 06:42 PM
Do these have provision for an emergency brake, also what weight saving is there over 11" drums on my dana.
Mick
Posted By: DoctorDiff
Re: DoctorDiff's rear disc kit - 10/02/10 09:19 PM
Andy,
Yes, Ford discountinued the traditional Explorer rear disc brake kit a few months ago. I think Currie Enterprises is now the oly source for that kit.
I haven't tried the new Motorsport rear disc brake kit.
Deaks,
If I remember correctly, my standard 10.7" rear disc brake kit weighs 21 lbs per side. Parking brake cables are included.
Posted By: Kiddart
Re: DoctorDiff's rear disc kit - 10/03/10 02:03 PM
Doctor Diff do you have a web site to review the kits??
Posted By: 74_360_Cuda
Re: DoctorDiff's rear disc kit - 05/03/11 03:42 AM
Quote:
Doctor Diff do you have a web site to review the kits??
Posted By: AndyF
Re: DoctorDiff's rear disc kit - 05/03/11 05:09 AM
His website is in his profile.
Posted By: DoctorDiff
Re: DoctorDiff's rear disc kit - 05/03/11 06:06 AM
Unfortunately, my website is out of date. It does contain links to my eBay listings, which feature the 10.7" rear disc brake kit, however.
www.doctordiff.com
Posted By: clovis
Re: DoctorDiff's rear disc kit - 05/06/11 02:26 AM
This is a pretty cost effective solution Cass put together for me. He supplied the re-drilled GM rotors and bolt on brackets. I supplied the GM Metric calipers and line kit. It requires a few little mods on the calipers but overall this is strictly a bolt on upgrade for around $300. You can get the calipers in a 2 3/8 piston, instead of the normal 2 1/2, which with the small 10.5 rotors makes the bias work out good.
Posted By: clovis
Re: DoctorDiff's rear disc kit - 05/06/11 02:32 AM
more pics
Posted By: clovis
Re: DoctorDiff's rear disc kit - 05/06/11 02:39 AM
one more
Posted By: juicedcuda
Re: DoctorDiff's rear disc kit - 05/06/11 02:58 AM
What is the weight savings over the big Dana drums? I don't know what they weigh.
Posted By: 74_360_Cuda
Re: DoctorDiff's rear disc kit - 05/06/11 03:33 AM
Quote:
You can get the calipers in a 2 3/8 piston, instead of the normal 2 1/2, which with the small 10.5 rotors makes the bias work out good.
Do you have stock front end?
Booster?
Posted By: Evil Spirit
Re: DoctorDiff's rear disc kit - 05/06/11 03:45 AM
I remember either Currie or Speedway had a similar kit a couple of years ago at about the same price ($300) but I haven't seen it listed lately on the Speedway site - I haven't looked at Currie's.
Posted By: DoctorDiff
Re: DoctorDiff's rear disc kit - 05/06/11 03:53 AM
The last posts show my new low cost (bolt-on) 11" GM Metric based rear disc brake kit. It is best suited for drag cars with skinny tires on the front of the car, and large tires on the rear. This brake kit yields more rear bias, as 2", 2 3/8" and 2 1/2" bore calipers are available. Even though they will interchange, I don't recommend using the troublesome GM caliper with the built in parking brake.
I recommend my 10.7" or 11.7", Mustang Cobra based rear disc brake kits for other (street/handling) applications. These kits incorporate a reliable, integral parking brake mechanism and small (1.5") pistons for cars that require less rear brake bias.
Posted By: Crazy68Dart
Re: DoctorDiff's rear disc kit - 05/06/11 04:57 PM
Too bad about the SVO (Explorer kit) being discontinued. That was a pretty cost effective setup, been a long time since I bought it from you Cass, but I remember it was in the 300 range as well? Works well with the Lokar e-brake cables.
Posted By: DoctorDiff
Re: DoctorDiff's rear disc kit - 05/06/11 06:13 PM
Yes, the old Explorer rear disc brake kit retailed for $400.
Posted By: maximum entropy
Re: DoctorDiff's rear disc kit - 05/06/11 09:24 PM
Quote:
These look great.
Can I ask a dumb question??? Well I'm gonna......
If you don't have green bearings and they are required for a brake setup, what can happen? What do you gain? Lose?
Thanks in advance
i'm going way back in me head, so the details are foggy. iirc, the green bearings are ball bearings, which are not particularly well suited to high lateral loading (road racing, in this instance). the tapered rollers are better suited to a road race application.
Posted By: clovis
Re: DoctorDiff's rear disc kit - 05/07/11 05:51 AM
Do you have stock front end?
Booster?
Yes I have the stock front disc that came on my car ('75 Duster), but I do run a '95 Mustang master cylinder.
Posted By: 72Swinger
Re: DoctorDiff's rear disc kit - 05/20/11 07:40 AM
Quote:
I have many miles on this set up, it works, the rotors are wearing nicely and are not warped...I ran for years with the stock stock two piece rotor/calipers with carbon metallic pads, no problems with the rotors, just some fade and poor pad life. [hint it's in the bearing preload]
Care to elaborate? I could use a good ninja bearing preload trick! PM if you'd like please.............