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Wilwood Dynapro 4R Rear Disc Brake Kit - 12.19 inch, Lg Bearing, 66-75 Ford Bronco SKU: 140-13733N
Wilwood Dynapro 4R Rear Disc Brake Kit - 12.19 inch, Lg Bearing, 66-75 Ford Bronco
Wilwood Dynapro 4R 12.19" Rear Disc Brakes 66-75 Bronco Lg Bearing
Product Overview:
This Wilwood DPL Pro-Series Rear Disc Brake Kit provides a complete solution for your 66-75 Bronco rear axle with Small Ford flange and bearing and compliment front big brake upgrades available for Bronco platform.
Requires minimum 15 inch wheel diameter. Not all 15" wheels will fit. Consult the Wheel Clearance Diagram in additional images to confirm fitment before purchasing.
Full description
This Wilwood DPL Pro-Series Rear Disc Brake Kit provides a complete solution for your 66-75 Bronco rear axle with Small Ford flange and bearing and compliment front big brake upgrades available for Bronco platform.
Requires minimum 15 inch wheel diameter. Not all 15" wheels will fit. Consult the Wheel Clearance Diagram in additional images to confirm fitment before purchasing.
Requires minimum 15 inch wheel diameter. Not all 15" wheels will fit. Consult the Wheel Clearance Diagram in additional images to confirm fitment before purchasing.
Wilwood Dynapro 4R Rear Disc Brake Kit | 66–75 Ford Bronco
For Large Bearing Axle with 11" x 1-3/4" Rear Drums | 12.19" Rotors
Take your Bronco’s braking power to the next level with Wilwood's Dynapro 4R Rear Disc Brake Kit. Designed specifically for 66–75 Ford Broncos equipped with large bearing rear axles and 11" x 1-3/4" rear drums, this complete solution brings modern stopping performance to your classic rig.
This kit includes powerful four-piston Dynapro Lug Mount calipers, 12.19" one-piece drum/rotors, and high-friction pads for balanced braking that perfectly complements front big brake upgrades. Plus, it includes an internal parking brake system hidden neatly inside the rotor hat for a clean look and reliable hold.
Ideal for Broncos with 15" wheels, this kit is finished in sleek black for that custom, understated appearance. It works with the Big Ford Bronco axle flange (2" offset), and the forged billet calipers provide premium performance and strength you can count on both on and off the trail.
Customize your look and performance with optional rotor designs and caliper finishes!
Specifications
| Specification | Detail |
|---|---|
| Pistons | 4 |
| Rotor Diameter | 12.19" |
| Caliper Mount | Lug |
| Wheel Diameter | 15" minimum required |
| Flange | Big Ford (Bronco) |
| Axle Offset | 2" |
| Finish | Black calipers |
| Parking Brake | Integrated internal drum-in-hat design |
Why You Need to Know Your Axle
This kit is specifically designed for Broncos with the large bearing rear axle and 11" x 1-3/4" drum brakes. Confirming your axle type is critical for proper fitment and brake performance. If you need help identifying your axle, see the "Specs" section below!
Note: Brake Kit does not include flex lines. Flex lines are necessary to complete the installation of the kit and must be ordered separately.
Note: Kit may not fit all 15" wheels. Check wheel clearance diagram in kit installation instructions before purchase.
CAREFULLY CHOOSE THE RIGHT KIT
Let's cover some basics. The rear end refers to the entire rear axle assembly. The different parts of the rear end are the brakes, axles, axle housing, and the third member. The most common question we are asked is "How do I tell if I have a large or small bearing rear axle?" You can easily identify if you have large or small bearing axles by examining the ends of the axle housing.Photo 1 shows a small bearing axle housing. If you look close at the housing right where it meets the backing plate, there is no noticeable size increase where the axle bearing pocket is. Photo 2 and 3 show a large bearing axle housing and you can see a noticeable size increase where the axle housing meets the backing plate. If you have loose axles laying around, you can simply measure the outside diameter of the bearing. The small are 2.835" or just under 3" and the large are 3.150" or just over 3".
There are 4 different sets of rear axles that would have come stock in 66-77 Broncos. The original applications are as follows:
1. 66-75 small bearing,
2. 66-75 large bearing,
3. 74-75 medium duty large bearing, and
4. 76-77 large bearing.
Each of these sets have a driver and a passenger side axle. Each of these sets use corresponding backing plates and brake drums. The backing plates and drums are particular to each set and are not interchangeable with the exception of the 66-75 small bearing and 74-75 medium duty large bearing using the same brake drum.
So, how can you identify which large bearing set you have? it can be narrowed down this way: The inside diameter of the Bronco rear brake drum is approximately 10" or 11". So, if you have a large bearing and a 10" brake drum, you have what we call a 74-75 medium duty setup. That leaves us with the 66-75 large and 76-77 large. Both use an 11" brake drum. The 66-75 uses a narrower drum and corresponding brake shoes. We identify this as 11 X 1 3/4". The 76-77 uses an 11 X 2 1/4" drum and shoe. Note the difference in the backing plates * in photos 2 and 3. Photo 2 shows a 66-75 large bearing with 11 X 1 3/4" brakes. Photo 3 shows a 76-77 with 11 X 2 1/4" brakes. If you look close you can see the backing plate of the 66-75 appears wider. Please note that all of the original axle sets were 28 spline. See Photo 4. With an increase in spline count comes an increase in outside diameter of the axle and so you get an increase of strength. A very common upgrade is to install a set of 31 spline axles. All that is necessary to do this is a set of axles and a new differential and we would recommend a third member rebuild kit. 35 spline axles are another step up in the strength department but usually require a new differential housing. The 35 spline axle is common for the extreme rock crawlers.
The third member, also known as the differential housing, hogs head, and chunk, holds the differential, ring and pinion gears, and bearings. This is the part that bolts into the center of the axle housing. See photo 5. You have three choices of gear ratios that were stock. They would be 3.50 which is the most common, 4.11 and 4.56. There are many other ratios that can be used as well. The differential refers to the ring gear carrier and came stock either open or limited slip "posi" type. There are numerous upgrades such as Detroit Locker, ARB air locker, electric lockers, etc.
Instruction 1
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Q&A
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Asked by Anonymous, April 30, 2021
Q: Two questions:
Will these will work on the Ford 9 from the 78-79 Broncos or similar F150s?
Is there a larger versions that fit 16 wheels, similar to the the sets you sell for the D44 (12 disc)?
⮞ 1 Answer
Answered by ☆ sales - May 5, 2021
A: No, is the quick and easy answer. Wilwood may offer a kit that could work, but not always, even for the 66-77 Bronco. We jump from 15 to 17 on the rear, so normally the 16 in the front and 15 in the rear. Look through their instructions. Wilwood lists all the requirements for fitment. Found on each kits product page. You are probably closest to the 76-77 Bronco.
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