Best/Easiest rear disc brake conversion 81 sx4?

[olymunch]

So looking around I can't find a difinitive answer as to what will work the easiest with the stock axle. What year make and model should I look for from a junk yard? Or a parts store? I'm looking for the least amount of fab.
Thanks

[eaglefreek]

I don't know of any vehicle that the you can use the disc brakes from and bolt to the AMC 15 axle. It will be 100% custom. Depending on your gear ratio, it might be easier to find a Dana 35 or Chrysler 8.25 out of a Cherokee and get the rear disc brakes from a Grand Cherokee. Another option is to use an axle from a Ford Explorer.

[rollguy]

I don't know of any vehicle that the you can use the disc brakes from and bolt to the AMC 15 axle. It will be 100% custom. Depending on your gear ratio, it might be easier to find a Dana 35 or Chrysler 8.25 out of a Cherokee and get the rear disc brakes from a Grand Cherokee. Another option is to use an axle from a Ford Explorer.

Agreed.  On my '82 SX4 (avatar photo), I had to fab my rear disc brakes from different parts.  I used the caliper brackets from a full size Cherokee (Dana 44), the calipers from a Cadillac ElDorado, and the rotors from a Scout (5.5" bolt circle).  I had to turn down the axle flanges to fit inside the rotors, and modify the caliper mounts to bolt onto the 4 bearing retainer (backing plate removed) bolts.  An AMC 15 might be even easier using Cherokee rotors, calipers and modified caliper brackets.  The only thing you won't have is a parking brake.  That is why I used Cadillac rear calipers, they had a parking brake assembly as part of the caliper.   

[Amc1320]

Many years ago a friend of mine put a rear disk set up from a Lincoln Versailles (looks like a Granada ) under an AMC it was a pretty easy swap and required very little modification

Haven't seen one of those in a junk yard in years

Of course that was a 2wd car so ratio didn't matter at the time, but I remember it fit the rear like a glove

[eaglefreek]

A few years back, I was messing around at a junkyard and found out Chrysler Concorde front rotors fit perfect on the rear axle of an Eagle. But have no idea if the offset would work properly when a caliper was installed to clear the rear wheel. http://www.tsmmfg.com/ makes a kit for the AMC 20. I wonder if they had the specs so they could make you a bolt in bracket for the AMC 15.

[rollguy]

A few years back, I was messing around at a junkyard and found out Chrysler Concorde front rotors fit perfect on the rear axle of an Eagle. But have no idea if the offset would work properly when a caliper was installed to clear the rear wheel. http://www.tsmmfg.com/ makes a kit for the AMC 20. I wonder if they had the specs so they could make you a bolt in bracket for the AMC 15.

I wonder how much different the 15 is from the 20?

[olymunch]

Wow thats a lot of good info. What axle came stock on an 81 sx4 and how to you tell what you've got? This will help a lot on my quest for disc brakes WITH a parking brake.

[TLC87Eagle]

Every time I flip through a 4WD Hardware catalog, I notice a few sets of Rear Disc Conversion sets and wonder if they would work for our Eagles. I don't want to spend that much time and money though to find out they don't work.   

Here's one set that looks the most promising...

http://www.4wd.com/Jeep-Brakes-and-Steering/Disc-Brake-Conversion-Kit.aspx?t_c=65&t_s=541&t_pt=10397&t_pn=G%2f296-2049-DB

Looks like they would just bolt on to where our backing plates go, but I really don't know.

[BenM]

There should only be negligible difference between an AMC 15 and a Dana 35; Dana bought the tooling for the 15 from AMC and used it for the 35.

The 95-98 ZJ (Grand Cherokee) had discs on a Dana 35. You will need a different master cylinder as well.

I've seen these guys mentioned a few times before: http://www.tsmmfg.com/jeeprear.html

[attemptnumber2]

i will test this D35 vs. AMC 15 theory since I have the parts laying around. I feel like i am going to have to pull the axles to test this though

[carnuck]

The backing plate pattern changed from M15 to D35 due to the bigger bearings (and it's Mopar pattern)