Rear brake options for 8 1/4" and 8 3/4" axles

[Kern Dog]

Hello all,
I have a few rear axles here that have no brakes on them. In the past, I'd just go to the nearby self serve wrecking yards and grab some 10" drum assemblies and use them. As the rear wheel drive cars are harder to find, I'm having to expand my search.
I have seen trucks and vans with 8 1/4 and 9 1/4 axles. The 5 lug hub versions usually have 11" brakes. Thats a bit oversized for what I want but it is better than nothing. I once swapped Dakota 10" drums onto an 8 3/4 axle. I could do that again if it comes down to it.
See, I have a 65 Valiant that will get a 3.21 geared 8 1/4" axle. It came to me without brakes. A car this light would be fine with 11" discs and 10" drums. I have a 72 Duster that is getting a 3.55 geared 8 1/4" and it needs brakes too. My '70 Charger project car currently has an 8 1/4" but will get an 8 3/4" when I find some brakes for it.
I have a fuzzy memory of people adapting Jeep rear discs to 8 1/4" axles. What does it take to make that work? Jeeps and Durangos are common in the yards. Is there a range of year models that I need to search for?
I have a couple of 8 3/4 axles that need brakes too. One has the stock tapered bearings, the other has fixed/non adjustable type bearings. Can the Jeep/Durango discs be fitted to them?
I'm not fixated on any specific type of brake. Drum or disc will work, I just need something that requires no trips to a machine shop and has no no crazy or unusual parking brake cable arrangements.

[Montclaire]

I believe you are looking for first gen jeep libertys for the 8.25 rear disc setup.  I have heard that it bolts right on earlier 8.25s but you will have to cobble something for the parking brake.  I don't know if they had a rear drum option on the liberty but 8.25s were pretty common in jeep cherokees (xj).  I have no idea on 8.75s except to search for truck/van/chrysler applications. 

[John_Kunkel]

A while back Rick Ehrenberg did an article in Mopar Action where he performed a rear disc swap using junkyard Jeep parts. Two-part article in late summer of 2018.

[Kern Dog]

Thank you. I apologize for not being clear. I meant to say Jeep CHEROKEE models, not the Liberty.
I do have the Mopar Action magazines and have read them. While the Liberty brake swap does seem to work, they require machine work to get there. I may resort to that but first, I would like to see if I can find something that just fits as is.


I went out to a couple of "Pick N Pull" yards today.
These guys  embraced an annoying business model a few years ago. They have made it more customer friendly for the people that rarely ever go to the yards BUT it slows down everything for the people that know what they are doing. The cashier offers to look up their inventory for customers, to print out a list of the cars, to quote prices too. All the while, I have already looked at their online inventory and I know where the cars are in the yard.
I wanted to find some 10" drum brakes. Simple, effective and relatively light.
No rear wheel drive classics at the 2 yards I went to. The first was supposed to have a '69 Fury but the car was not there. This is a common thing....their inventory is rarely ever 100% accurate.
I did see several Jeep Cherokees with 9" and 10" drums and discs. A few of them had what looked like something smaller than the 8 1/4" axle so I doubted that the backing plates would have had the right bolt pattern. The Cherokees seem to use a weird parking brake setup too. The Liberty models do as well.
The 1/2 ton trucks and vans that did have rear drums were  11" and the bigger 5x5 bolt pattern that started sometime around the 1985 model year. I saw several Jeeps and a few Dakota trucks with both disc and drum brakes.
I did find a '73 Van with an 8 3/4" axle and 11" brakes. I pulled the 3.23 3rd member and the brakes. The shoes were worn out, the van looked to have been sitting for 20 years so I suspect that the wheel cylinders were rusted solid too.
The counter monkey did what most of them do: Itemize every individual part. Brake shoes. Springs. Wheel cylinders. Parking brake levers. Backing plates. Drums.
I asked if they had a sales code for a "Brake assembly". He said no.
$ 126 for the two drum assemblies with all the fees. The drums were rusty and the backing plates were heavily pitted. $126 for parts that aren't exactly what I wanted and I'd need at least another $70 or more in parts to make the brakes complete. I'd be in the set $200 easily.
The 3rd member was $130.
That is $250 for brakes and gears. The entire axle complete would have been right at $200 but I already have several axles here that need brakes !

Junkyarding used to be cheap.
I could wait until they have another 1/2 price sale but the problem for me is, I don't find the classic parts  in these yards all that often anymore. I usually just grab it when I see it. I just couldn't justify the price on the rusty brakes though.

[Montclaire]

Not much of a deal.  I remember reading a blog post about the Grand Cherokee discs being adapted to an older 8.25 axle.  It worked but the liberty swap had fewer steps. 

I also came across several posts about drum backing plates.  The same backing plate MAY fit 8.25, 8.75, and even the 7 inch axles with the BBP.  The difference is the brake shoe width.  The A-body 8.75 plates also seem to have a different offset so you have to be careful at what you are looking at. 

[Kern Dog]

Thanks,
A guy on FBBO says that the Diplomat/Fifth Avenue/Gran Fury cars with 7 1/4" axles also used the same backing plate bolt pattern. I wish I'd have known that years ago...I would have been grabbing them back when the cars were more plentiful.

[BrianShaughnessy]

Aside from the backing plates which can be found on ebay if you look ...   anything else I'd probably buy new.   Well if the drums are OK maybe?   Find somebody to turn them anymore LOL.

My experience with aftermarket rear disk kit on Betty made me stick with drums on Sinnamon.   That was green bearings only.   If you have factory taper bearings don't bother.

Only rear disk kit I feel like trusting would be Dr. Diff's and that's using Mustang parts.  But at least it's almost 'factory' - just don't ask what factory.   

The Jeep rear disk swap is sketchy with parking brake cables.   It's not clean.

If I was building a rear end from scratch I'd use ford ends and torino bearing axles and figure out the brakes from there.

[Montclaire]

I never felt the need for rear discs.  If it was me I would hunt around for those late 7.25 plates and call it a day.  You might still get lucky and find USA made drums at a NAPA but it's a crap shoot.

[Kern Dog]

Only rear disk kit I feel like trusting would be Dr. Diff's and that's using Mustang parts.  But at least it's almost 'factory' - just don't ask what factory.   

I actually have one of the early rear disc kits from Dr Diff in my red car. 10.7" Toyota rotors, Mustang calipers and pads and his own aluminum bracket.
For the other cars, 10 inch drums or cheap discs that don't necessarily look great are fine.

[BrianShaughnessy]

Getting any kind of 3rd member for $130 would be a good deal up here anymore.   

I paid about that like 10 years ago for the open 3.23 for Sinn...   bought a Detroit TrueTrac off Summit. 

The Dr. Diff stuff works good?    Nice.

Good luck with the rest.