Front Brake Upgrade

[Blip Downshift]

So, I believe I am in the final stretch of my rear disc brake conversion using the stock M15 axle.  So I am looking forward to a possible performance upgrade for the front brakes.  The key to many of the upgrades I've found in suspension, braking, and drivetrain all come from the concept that, while the Eagle has little to zero aftermarket support, AMC used parts from other automakers to keep costs low.  That means, with some dedicated sleuthing, performance parts that fit vehicles using the same or similar configurations may work.   This outlook allowed me to fit a D35 truetrac differential into my M15 diff housing and to a lesser extent fit an early D35 disc conversion (with some modifications) to my M15 axle housings.  I've found a lot of the Eagle community either says it wont work but has also never really tried (if you have, I'd like to hear from you).  It wont be cheap, but nothing good is.  So to start off, I have an 81 Eagle SX4.  The best place to start is with the parts catalogs to see what parts interchange with which vehicles.  The 1980-81 AMC Spirits, Eagles, and Concords all share their front braking calipers and brackets with the Ford F100 pickups.  The late 70's early 80's F100 has almost as little aftermarket support as the Eagle.  Now the 82-88 Eagle shares its front braking components with the 84-90 XJ Cherokee and 86-90ish YJ Wrangler.  There is huge aftermarket support for these vehicles.  So my next questions are; will a 82-88 Eagle brake caliper bracket fit on the 80-81 bracket mount?  Will 82-88 Eagle spindles fit on a 80-81 Eagle?  and will the 82-88 Eagle caliper bracket mount attach to 80-81 spindles?  These are all various options what would make this theoretically possible.  I already bought some cheap ebay parts to try some test fitting and if I can make 82-88 Eagle front brake system work on a 80-81 Eagle there may be something to this.  If these do fit, then I will buy the performance (expensive) caliper bracket from Woodward to see if it will fit.  I will post updates as I find out.  I hope this works.

[vangremlin]

Good luck!  Let us know what other parts work with your Eagle!

[amcfool1]

hi, check R1Concepts.com   , they may have drilled/slotted rotors    good luck,  gz

[Blip Downshift]

amcfool1, I appreciate the advice.  I already own a set of these rotors.

[Blip Downshift]

Ok, so I bought a front brake caliper bracket from a early YJ Cherokee for test purposes and it doesn't fit my setup at all.  Which I guess was suspected all along.  The mounting holes are much more spaced on the YJ bracket and from what I've seen even more so on the 82-88 Eagle brackets.
 

Here are some pictures of the 80-81 caliber brackets beside a YJ Cherokee bracket.  I've seen pictures (which I not can't find) of the 82-88 Eagle brackets and they do mount to the same caliper but the bracket mounting points look different.  I'm not sure if AMC made completely different caliper brackets for these years or just produced an adapter part to make it work (maybe both).  It looks like the caliper brackets for the 82-88 Eagles are modified to fit on to the Eagle spindle, which looks unchanged from year to year.  I haven't fully verified this yet.  If anyone has any photos of the later Eagles caliper brackets, the mounting points, and more specifically them mounted on the car, I would greatly appreciate it.  The hunt goes on.

[AMC of Houston]

Regarding the spindles, the AMC parts books say the same spindle was used from '82 thru '88 (J3240900).   Spindles for the '80 & '81 show different part numbers, so something must have been different on those -- but I don't know what.