Explorer rear disc swap for 9" big bearing

[MisterPero]

I am considering the Explorer rear disc swap on the 9" with the big bearing setup/hole spacing. Has anyone had success with this swap? Is it just a matter of slotting the holes on the Explorer backing plate to align with the holes on the axle retainer plate? If there is already a tech thread on this, please point me in that direction. Thanks.

 

[DirtDonk]

Back to the top MisterPero.
Don’t have the exact answer so hopefully someone can fill in the details. But for a large bearing rear end housing I don’t believe it’s as simple as bolt and go, or even elongating the bolt holes.
If I remember, the shape of the housing doesn’t fit the recess in the explorer backing plate/mounting bracket.
That’s why the most desirable bronco housing for a quick swap was the 74/75 “medium duty“ bearing set up.
It can be done, and the housings can be made to mate up with each other. Our old rear disc brake kit used to include brackets that were slightly modified to work with the large bearing ends.
I just don’t know the details of the modification.

 

[toddz69]

There's a thread on here somewhere that shows how the holes need to be modified to work with the standard big bearing setup. It includes a drawing from @70_Steve that shows the details. I came across it some time ago and printed out a copy for my files. Of course - I now did a quick search and couldn't find it.

Edit - I found the thread. The pdf is in one of Steve's posts.

Todd Z.

 

[MisterPero]

Thanks for the help, guys. I found posts on other forums (https://www.jalopyjournal.com/forum/threads/9-inch-rear-disc-brake-installation.569272/) that indicate this is not an unprecedented challenge though the "Torino"/medium duty housing is the preferred plug and play 9" option for this swap. I'll get my hands on a backing plate and see how difficult the modifications will be to make this work with the big bearing that came on my 69.

Curious that the Explorer setup is not a common aftermarket option. Most of the swap kits I'm seeing on the Bronco vendor sites use the GM calipers, which if the forum chatter is reliable, have inferior parking brakes.

 

[toddz69]

Curious that the Explorer setup is not a common aftermarket option. Most of the swap kits I'm seeing on the Bronco vendor sites use the GM calipers, which if the forum chatter is reliable, have inferior parking brakes.

It probably is the most common aftermarket option after the GM calipers you mention. The details/challenges adapting the Explorer stuff to the various Ford rearends has probably held it back in terms of overtaking the GM stuff.

The GM calipers (most frequently found on Cadillac Eldorados - hence the usual reference to Caddy/Eldorado calipers) were one of the few rear disc brake calipers available as a swap candidate back when people first started putting rear discs on 9" rear ends with any regularity. The other two options that had parking brakes also had their challenges (Versailles - scarity and prized by the Mustang crowd, and Lincoln Mark V, which required some work too). TSM was the company that really started with the GM stuff in the '90s and they figured out that with some fairly basic brackets and some Jeep CJ rotors, they could cover a wide number of vehicle applications. I pulled and shipped dozens of those calipers for people back in the '90s for their conversions. The GM calipers are now reproduced so their popularity has endured, despite their parking brake effectivity issues.

I've long advocated for kits using more modern calipers that have better functioning parking brakes. Master Power Brakes finally came up with some kits of their own using late model Mustang calipers a few years ago and I'm anxiously awaiting the results of @ba123's installation of those brakes to see how well the parking brake works. I have those brakes on my S197 Mustang and the parking brakes on it are nothing short of spectacular - the obvious difference being a much smaller tire diameter, so there's less torque being exerted on the friction surfaces. I'm hoping they work well with larger tires as well.

Todd Z.

 

[ba123]

Yeah, I’m hoping they work too! But they can’t be worse than the Caddy ones, I know that and worst case you at least get the huge benefit it NEVER having to adjust them even if you don’t use it.

They come a nice looking silver but I painted all black.



I’m waiting for my Gen V vintage air unit to come but I think I’m on the final stretch otherwise, maybe a few months before I get to test.

You definitely cannot use a rear side shock. There is no room. Good thing for me that I set this up for both sides.

 

[Jeff10]

Hey Everyone,

I am trying to get up to speed on checking/troubleshooting the parking brake setup on the '70. It has an Explorer disc conversion on it (according to the previous owner).

It's already installed... I'm just not sure that it is correct. I was wondering, as was MisterPero, if maybe there's a tech article that would help.

Thanks,

Jeff

 

[ba123]

Hey Everyone,

I am trying to get up to speed on checking/troubleshooting the parking brake setup on the '70. It has an Explorer disc conversion on it (according to the previous owner).

It's already installed... I'm just not sure that it is correct. I was wondering, as was MisterPero, if maybe there's a tech article that would help.

Thanks,

Jeff

I can't answer your question about an article and don't know the explorer disc either, but a description of your issue and some pics would be great if you have them.

Of maybe they just don't work very well and no other issue?

 

[Jeff10]

Hi ba123,

You're right. Pictures sure help.

Looking at the cables, the first thing I saw was that the driver side cable wasn't positioned in the sleeve on the bracket. (I inserted it in one of later pictures.)

I am able pull the cable by pulling on the sleeve and operated the driver side e-brake, although I didn't check to see if the brake actually worked at that time. It took a lot of force to move the e-brake lever on the axle.

Trying to operate the pedal in the cab doesn't work at all. I can't put enough force on it to even move it.

I'm not sure if the main problem is the e-brakes themselves on each wheel, or the way the cables are run.

I've never worked on parking brakes before... so this is new territory.

(The shop that did a lot of work on the '71 really shyed away from trying to correct the parking brake operation on that Bronco. I don't recall which conversion it was; but, I want to say that it is either Cadillac or Explorer, too. For as skilled as this shop was at other things I found it interesting that they were so reluctant to work on that parking brake.)

Let me know if any other pictures would help. All of the pictures I am including are of the driver side.

Thanks,

Jeff

 

[Oldtimer]

You are missing some parts, which reduce the pedal effort.

 

[Jeff10]

Hi Old-timer,

Thanks for catching that!

That makes a lot of sense.

There are a lot of reasons why the saying about doing things yourself really applies to this Bronco. If nothing else I am learning a lot.

I need to look through the parts I have for that lever. I'll report back.

Jeff

 

[markw]

Jeff, I have one question. How is that all so clean under there?


Sent from my iPhone using Tapatalk

 

[Jeff10]

Hi Mark,

Looking clean probably has a lot to do with being a 12+ year project with a whopping ~ 150 miles driven during that time period. Lol

How are you?

Jeff

 

[ba123]

To me that looks like a non-stock setup so maybe you don’t need the lever, but as oldtimer mentioned, maybe that’s why you can’t make it move.

Even without that lever, I’d think it would move a little but would just be tough.

Maybe check to see if it moves with the cables disconnected from the brakes to make sure it not stuck cables or something?

 

[Joe473]

Thanks for the help, guys. I found posts on other forums (https://www.jalopyjournal.com/forum/threads/9-inch-rear-disc-brake-installation.569272/) that indicate this is not an unprecedented challenge though the "Torino"/medium duty housing is the preferred plug and play 9" option for this swap. I'll get my hands on a backing plate and see how difficult the modifications will be to make this work with the big bearing that came on my 69.

Curious that the Explorer setup is not a common aftermarket option. Most of the swap kits I'm seeing on the Bronco vendor sites use the GM calipers, which if the forum chatter is reliable, have inferior parking brakes.

Curious to hear of what you find out. There is an explorer kit on the web that states it works for torino style and small bearing housings. Our big bearing housing are different than torino style.

It also appears this will increase track width by half inch. On an uncut with 10.5" wide tires on stock rims that could be an issue.

Any experience on here that can confirm?

https://www.quickperformance.com/Fo...ke-Kit-With-Shoe-Style-Park-Brake_p_4023.html

 

[Yeller]

Will soon….. but not today

 

[StnePny]

Curious to hear of what you find out. There is an explorer kit on the web that states it works for torino style and small bearing housings. Our big bearing housing are different than torino style.

It also appears this will increase track width by half inch. On an uncut with 10.5" wide tires on stock rims that could be an issue.

Any experience on here that can confirm?

https://www.quickperformance.com/Fo...ke-Kit-With-Shoe-Style-Park-Brake_p_4023.html

That is the Ford Motorsports M-2300-G Disc Brake Kit ('96-'01 Explorer) that is the BOLT ON for the '74 - '75 Bronco (medium duty rear end - I believe it is because of the 3/8" bolts & 2' bolt spacing up & down) is what was a bolt on for my 1974 Bronco. The ONLY Machining work needed was to get toe Rotors DRILLED to 5" x 5.5" (they come 5' x 4.5".

For what it is worth (aka my $.02),.... You might want to purchase a "74 - '75 Weld - On Axle Flange to use as a " template "...to see where you will have to " Drill / Elongate / Keyhole " your axle flanges on your housing or buy duplicate axle flange plates to match your axles as a guide to " Drill /Elongate / Keyhole which will probably be a 1/2" bolt to match the change to the Explorer Backing Plate (which might be easier to do than the flange on your axle.

And, the Explorer Rotors will have to be machined to 5" x 5.5"

 

[toddz69]

Post #5 in this thread is very informative on the location of the holes relative to each other in the various bearing patterns:

https://classicbroncos.com/forums/threads/rear-disc-brakes.255331/

Todd Z.

 

[Joe473]

Post #5 in this thread is very informative on the location of the holes relative to each other in the various bearing patterns:

https://classicbroncos.com/forums/threads/rear-disc-brakes.255331/

Todd Z.

Thank you!

 

[Joe473]

That is the Ford Motorsports M-2300-G Disc Brake Kit ('96-'01 Explorer) that is the BOLT ON for the '74 - '75 Bronco (medium duty rear end - I believe it is because of the 3/8" bolts & 2' bolt spacing up & down) is what was a bolt on for my 1974 Bronco. The ONLY Machining work needed was to get toe Rotors DRILLED to 5" x 5.5" (they come 5' x 4.5".

For what it is worth (aka my $.02),.... You might want to purchase a "74 - '75 Weld - On Axle Flange to use as a " template "...to see where you will have to " Drill / Elongate / Keyhole " your axle flanges on your housing or buy duplicate axle flange plates to match your axles as a guide to " Drill /Elongate / Keyhole which will probably be a 1/2" bolt to match the change to the Explorer Backing Plate (which might be easier to do than the flange on your axle.

And, the Explorer Rotors will have to be machined to 5" x 5.5"

Thanks, that kit I linked has options for the rotor bolt circle and pattern. It also has the option to order with the torino or the 74-75.
How does the explorer parking brake work on our larger heavier tire?