Best rear disc kit for the money using the BB 76-77 9 inch rearend

[bigmuddy]

Have you looked at the bc kit. It uses off the shelf cj rotors and fits the 77 housing. It uses the caddy calipers that can be a pita to adjust but you can buy an electric kit that makes it easier.

SteveL I wasn't aware of that kit. Then again, I haven't done business with them in years for a number of reasons.

Interesting, I just looked and yeah that might work and they sell the kit without the calipers for $450
I would need to find an ebrake caliper that works?

I also saw they sell the wilwood kit that uses a separate ebrake caliper behind their 4 piston caliper which is interesting, but not enough to plunk down almost with tax and shipping!

 

[bigmuddy]

I'm thinking this maybe a winter time R&D project.

 

[ntsqd]

As a semi brake nerd I dislike the Cad caliper solution because of the large pistons. They're too large, you end up having to dial out a bunch of excess braking capacity by screwing the p-valve way down. Better is to use a caliper with a smaller piston that gets the truck closer to a brake bias that needs no p-valve. The brake torque generated by the Explorer system appears to be the closest yet to hitting that sweet spot.

 

[SteveL]

SteveL I wasn't aware of that kit. Then again, I haven't done business with them in years for a number of reasons.

Interesting, I just looked and yeah that might work and they sell the kit without the calipers for $450
I would need to find an ebrake caliper that works?

I also saw they sell the wilwood kit that uses a separate ebrake caliper behind their 4 piston caliper which is interesting, but not enough to plunk down almost with tax and shipping!

It wasn't an electric caliper but an adjustable piston that pulls and releases the cables

 

[bigmuddy]

As a semi brake nerd I dislike the Cad caliper solution because of the large pistons. They're too large, you end up having to dial out a bunch of excess braking capacity by screwing the p-valve way down. Better is to use a caliper with a smaller piston that gets the truck closer to a brake bias that needs no p-valve. The brake torque generated by the Explorer system appears to be the closest yet to hitting that sweet spot.

I agree ntsqd, yet one more reason to not like the caddy calipers.

 

[Got4wd]

I called range today and gave him the specs on the 76-77 big bearing. He’s looking into it. Sure would clean up a ton of linkages, cables and brake pedal. I’m sure it can be done with the electric calipers

 

[fordguy]

The Torino ends are widely available. I saw one that slips over the axle tube

 

[bigmuddy]

He noted in the description that he isn't interested in pursuing other applications. You may need to design your own whole bracket assembly or part of it. It would be important to know what the axle flange to housing flange dimension of the Jeep D44's is.

The flange offset distance used by the Torino housing ends is 2.5" as I recall. Not saying that axles made to the 2.36" (?) dimension couldn't be bolted into them, but I think that the Explorer system also uses the 2.5" distance. I have read of someone making a pair of ring spacers that were .14" thick and installing them between the bearing shoulder and the bearing to use a 2.36" axle in a 2.5" application. If I did that I'd want those spacers made from something that was hardened after the machining.

The Explorer system will fit inside a 15" wheel. As I recall the Expedition system wants at least 16's and I'm running them inside of 17's.

wilwood's kit(s) were originally to be based on the Explorer system, but I seem to recall that someone found that the p-brake shoe is a Corvette part?

I heard back from Brennan.
My EEbrake conversion uses a mid-size ford suv/car caliper and a tracker/sidekick disc. I was trying for the smallest possible package to fit in a 15 inch wheel....and even that is a challenge.

He suggested mocking up various brackets with some 3d printing.

I am curious to see what Range comes back with has he seems to have a number of ebrake kits using Ford parts too.

 

[ntsqd]

With CAD and companies like Xometry & SendCutSend or OSHCut around it shouldn't be too hard to design your own brackets/bracket assemblies and have them made.

 

[bigmuddy]

With CAD and companies like Xometry & SendCutSend or OSHCut around it shouldn't be too hard to design your own brackets/bracket assemblies and have them made.

ntsqd, I don't disagree at all. This for me at least, unless Range comes up with something I will likely shelve it until over the winter.

More from Brennan correspondence:
I had mentioned the BCB kit for this rearend using the CJ rotor.

Brennan:
The CJ rotor is too thick. Most factory electric ebrake calipers use a thinner solid rotors. Only the larger pickup calipers start to get into using vented rotors, but then they have to use a fairly large diameter rotor as well.

I think having to use a 17 or larger wheel will severely limit the market when dealing with classic wheels.

I'm not against adapting my current system to a ford 9 inch, but I also don't want to start over from scratch with a bunch of other random parts for no real reason.

ME: So your saying there is a chance you could build it

 

[bigmuddy]

I didn't ask him to R&D or modify anything on his kit FYI.

 

[ntsqd]

Both the Explorer and the Expedition RDB's use non-vented rotors. I take it as a comment on how little heat those generate. Which in turn sheds some light on how hard they're working. Which isn't to imply that they don't get hot, just that shedding that heat fast enough for most driving doesn't require a vented rotor.

 

[SLOWnEASY]

If the front brakes handle 80 percent of the stopping, it would make sense that they don't really need a vented rotor on the back.

 

[ntsqd]

Have to be careful with trying to put an exact number on how much work the front or the rear brakes do. It's not simple, it depends on the vehicle and on the situation. A softly sprung Samurai on 40's in a panic stop is going to have a drastically different brake balance than an F-550 with a hot-shot car hauler goose-neck trailer that is fully loaded gently slowing down.

 

[jamesroney]

Have to be careful with trying to put an exact number on how much work the front or the rear brakes do. It's not simple, it depends on the vehicle and on the situation. A softly sprung Samurai on 40's in a panic stop is going to have a drastically different brake balance than an F-550 with a hot-shot car hauler goose-neck trailer that is fully loaded gently slowing down.

The circle is now complete.

Since I've no knowledge of the housing in question, what is the axle flange to housing flange dimension? I assume (y'all know what happens there) from the comment above that it uses the 'old' big bearing housing end rather than the Torino/'New' big bearing housing end?

I want to say that I've seen at least one other vendor who offered the Explorer rotors in several different bolt patterns, but I'm blanking on who it was.

Nominally 2-3/8 inch. Which is 2.375 inch. Which some people measure as 2.36. Depends on whether you include the metal gasket or the paper gasket.
Teraflex sells a dual pattern rotor for the TJ, but it costs more than the Currie ones.
Speedway motors used to sell the Explorer rotor in 5-5.5, but i can't find it any more.

The whole rear disc discussion on an early bronco is just silly. We all conclude that the rear brakes don't actually do anything, don't create heat, and don't really need to be there except as a parking brake. So anyone converting to discs is just doing it for bling. As soon as you put it in 4WD, the brake balance becomes irrelevant. So you are doing it for 2WD performance. (said no one ever in a Bronco...)

Then you need to figure out an emergency brake. Which puts you in three camps. Mechanical over hydraulic, (Cadillac / Mustang GT) Expanding shoes (Explorer/TJ) or Discrete caliper. All of these systems become far more complex and cumbersome than the original drum brake solution.

If you go Mechanical over hydraulic, you need to solve the brake balance, and crappy e-brake problem.
If you go expanding shoe brakes, you need to overcome the axle hat size problem, the impossible to assemble problem, and the scarcity of replacement parts problem.
If you go discrete caliper, you have to do all of the engineering and then spend a ton of money for an emergency brake that is vastly inferior to the one you abandoned.

After many years of doing this successfully, I have determined:
Original drum brakes are the best solution. If you have front discs...replace the wheel cylinders with 3/4 inch pistons from a 67 mustang.
Second is Explorer discs with torino ends, custom axles and rotors, and custom retainers.
Third is Wilwood with internal parking brake.
Fourth is small format Cadillac with reduced pistons and lots of maintenance.

Gotta run.

 

[ntsqd]

Rear brakes do do something, it just isn't as significant to stopping the vehicle as the front brakes are. When I was battling the rear system gaining air from somewhere over a distance of 250-275 miles driven the front brake pads wore out about 5 times faster than normal. So while the rear brakes may not generate the heat that the front brakes do, they are important and do have an effect on the whole.

I suggest that there are two variables left out of that summary, wet brake performance and unsprung mass.

Not brake performance in the wet, recently submerged brake performance. Discs are vastly more effective at self-clearing/cleaning than drums. Observe my avatar, that is the poster child for poor drum brake performance in any conditions. Even here on the Coastal Desert it has exposed me to the poor self-clearing/cleaning issues of drum brakes. Not to mention keeping them in adjustment. Bronco drums are simple to keep in adjustment by comparison, but the correct choice in a disc system results in no need to adjust the service brakes at all. Parking brakes of any flavor appear to always be needing some amount of periodic adjustment although so far the drum type p-brake in the Expedition RDB's (larger version of the Explorer RDB design) has only needed to be adjusted twice in ~5 years.

Then we get to unstrung mass, I know for a fact that the Expedition RDB's that I installed on the FSB's rear FF D60 weigh significantly less than the drums that the D60 had when it came to me. That's not a very fair comparison to an EB's rear drums, but it is the main reason that I went with rear discs on that axle. If all that you ever do is go slow the unsprung mass really isn't a concern. As soon as you go faster (on any type of surface) unsprung mass becomes more important to both performance and to ride quality.

 

[toddz69]

I suggest that there are two variables left out of that summary, wet brake performance and unsprung mass.

And one more for me - ease of maintenance.

Todd Z.

 

[lars]

I have garden variety Explorer rear disc brakes on my heavy, permanent hard top-equipped beast. To get the balance right in all conditions other than weighted down with all the camping gear known to man, I need to have my Wilwood proportioning valve cranked down as far as it will go. Otherwise the rear (Explorer) disc brakes lock up first.

Whatever. They stop me. Parking brake is so-so. The Expedition version of the same design with its larger rotor hat would be better. But @jamesroney's comment, if parking brake is Job 1, I'm guessing OEM drums are best and I agree with everything he wrote.

Except. My first rear axle only had the smallest of the small drums which were awful, then I went with a Currie big bearing housing, tried and hated Caddy disc brakes, then on to what I have now. Which has been on there for about 20 years. So I've never actually experienced what the largest drums Ford offered.

@ntsqd's comments about debris (I love that in England they pronounce that debriss) having unburied my ancient drums of silt prior to my previous and current setups, not to mention unsprung weight and complexity, meant a lot to me. It took me 18 years to wear out the first rear disc pads. Before that, zero maintenance.

Back when I first did my swap you couldn't buy pre-drilled Explorer rotors for 5 on 5.5 (or maybe you could but I was a cheapskate) so I made my own drilling fixture. Have yet to need it other than the first time but it's been put to use for others since.

 

[fordguy]

All things considered, the explorer disc rear in a Currie housing was simple. The cable contro handle between the seats was even easier with Lokar explorer brake cables. My rig is an automatic with 33s so emergency brake (pull handle) is adequate for parking and e-braking if needed. Cost was not outrageous. And yes it is a cool factor, considering I did not have drums or brake hardware. The 8.8 rear ends are cheap And explorer hardware is readily available and inexpensive.

 

[Yeller]

I’m late to the discussion… and honestly only had time to skim through. This Ford Motorsport kit from Quick Performance addresses most of the road blocks to the explorer RDB’s. Over the last couple of years it has become my go to brake kit.

I agree that drums are sufficient and P brake is superior, however their maintenance is a pain and replacement hardware kits suck. Hardware kits are why pushed me to disc conversion on my J Truck, they would not stay adjusted. Then there was the debris issues wheeling…. Also how many of you have driven your EB enough to need replacement rotors? Calipers due to being corroded and failed from lack of use? Definitely. the RDB’s on my bronco are on their 3rd vehicle and it has been driven a lot over the last 13 years and the previous 13 before that. Just put together been running that brake set up of 26 years…. Man time flies.