CobraMarty

15" DIY Big Brake Kit for XJ/MJ/TJ/YJ D30/44
There are many options for upgrading the stock XJ/MJ/TJ/YJ D30/44 front brakes.
Most are quite expensive or labor intensive.
Different BBK options depending on wheel size. 15", 16" or 17"+

15" Wheels BBK Options
-Stock D30 rotors and calipers- 11" rotor and single piston caliper
-WJ upgrade- 12"rotors and dual piston calipers, Requires welding, steering upgrade, different track bar and relocated sway bar mounts. Costs $1000+
-Vanco 15" kit- New Knuckles, 11.35" rotors and dual piston calipers, bolt on, $1060
-DIY 15" Kit- 12.01" rotors, dual piston calipers, bolt on, $500

DIY 15" Wheel BBK Parts Needed- 15" steel wheels required, Like Crager Soft 8. Other 15" wheels might require 1.5" spacers.
-'84-'89 XJ Knuckles (getting harder to find, Ebay $100-$150 set)
-14mm drill bit to drill out the knuckle caliper mounting hole (Ebay) get drill necked down to 1/2" or need to use a drill press(safest)
-4 caliper mounting bolts 14mm 1.5 45mm (BoltDepot.com)
-12 washers 14mm 10.9 steel (BoltDepot.com) (2 washers used for spacers per mounting bolt 0.18" thickness)
-calipers and brackets- Centric 141.58009/10 Durango/Grand Cherokee '11-'15 for 330mm rotor (or equivalent) (RockAuto.com)
-rotors- Centric 120.65082 Sport Trac front rotors (RockAuto.com) (need to make the wheel hub smaller diameter to fit inside these rotors, easily done with flapper wheel)
-pads- Centric 300.14550 semi-metallic (or your favorite compound)
-Banjo Bolts for brake lines- M10-1.0 Mopar 06508914AA -banjo bolts, Mopar 06502114 -copper washers for banjo bolts and hose
-Dorman 12709 speed bleeders M10-1.0x35mm- Love these for bleeding brakes!! (optional) Calipers come with regular bleeders

This is basically the 'WJ Brake Upgrade' without the welding, new WJ lower ball joint, new steering, relocated track bar axle bracket and new track bar, relocated sway bar mounts.
The WJ upgrade is very $$$$ and labor intensive.
This DIY 15" BBK is easy bolt on. Uses stock or your upgraded XJ or 1ton steering, stock trackbar location.

All this bolts on, retains your stock or upgraded steering
Total cost of 'DIY' 15" BBK is about $500.

Just be aware-
XJ calipers have 3/8"-24 bleeders and banjo bolts
The stock XJ parts will NOT work. They seem like they thread in but are wrong size.
Durango calipers have M10-1.0 bleeders and banjo bolts

This is not a kit for sale, just sharing a recent project. Totally 'Open Source'.
Other kits and upgrades are great products and ideas.
Many have asked for a BBK for 15/16" wheels.
I just wanted to do and share something different and cheaper.

15" Aluminum Wheels? It will be close. You need to measure the inside diameter. You need 14" for the caliper to clear. Might work with 1.5" spacers.

Jeep Driver

What is the equivalent to two washers? 3/16"? Why not just make a single plate with two holes?

CobraMarty

Washers are pretty simple and cheap. 2 washers for spacer are 0.18" thick.

3/16" (0.1875") single plate will NOT work. There is a rib/lip in the caliper bracket right where the plate would need to lay.

Nice part here is there is NO adapter bracket required. Calipers bolt directly to early knuckles. Caliper brackets and knuckles have the same bolt spacing.
Junk yard calipers would save $100-$150.

Thanks for looking and adding more ideas.

Jamie57

Well I have the knuckles so far. I have brand new USAlloy ball joints in my D30. The 87-89 knuckles have the threaded insert already in them. Will the new US Alloy lower ball joint work or do I need to get new joint for 87-89?

CobraMarty

I am pretty sure that the ball joints themselves are the same. Some come with the threaded insert, some don't. You could probably buy the threaded inserts separately if you need them but if your knuckles already have them and they look to be in good condition, I would think that you are good to go.

Your 15" Ion Alumn wheels, IDK if they will fit. You gotta measure inside diameter. You need at least 14". And you might need 1.5" spacers.

Jamie57

I'm running 3.75" backpacking on those rims. The stock caliper is pretty exposed now. I'll check it out. I was maybe thinking of getting those rims in 17" or 18" anyways when my house sells, so I could go to the 15" rotor. Was just looking at this for the time being.
I have 2 WJs an 00 and 02. The 02 has a great engine in it but body is clapped out. Was thinking of using the parts off it for the WJ swap but I was always thinking there has to be a better way.
You found it!

mwxj

The WJ setup still has its perks. Welding and relocation required yes, but you get crossover steering. And if you're paying $1k plus you're doing it wrong haha. I paid for welding and used new pets and mine still only came to about $700.

This looks like an awesome upgrade to those not wanting to deal with the fab though! Great write up!

cleenrob

i wish i had gone this route,

CobraMarty

Some have already upgraded steering and track bar relocation, etc for the stock XJ knuckles and and don't want to change everything all over to the WJ knuckles.

CobraMarty

Today DIY 15" Kit all fitted up and the 12"rotors and dual piston calipers clear 15" steel rims.
*Can't use stick on weights on the inside of the rim. They will hit the caliper. There is about 3/8" clearance between caliper and rim.
Can use clip on weights on the wheel inside edge, they will clear.

15" Alumn wheels didn't clear but later tonight I will try them with 1.5" spacer.

Photojared

Any pictures??

CobraMarty

I tried a Jeep Turbine Alumn wheel and 1.5" spacers and it barely fits. Needs minor clearance'ing of a corner on the caliper bracket.

I don't have any other alumn wheels to try.

CobraMarty

Photos are similar to those here-
https://www.cherokeeforum.com/f67/17...0-44-a-222937/

Just use 2 washers instead of the machined spacer to center the caliper on the rotor.

freegdr

Inserts need to be properly adjusted..

CobraMarty

DIY 15" Wheel BBK Parts Needed-
**15" steel wheels required, Like Crager Soft 8. Other Alumn 15" wheels will require 1.5" spacers and minimal clearance'ing of the caliper bracket**
**Can NOT use stick on wheel weights on the inside of the wheel. Can use the edge wheel weights**
-'84-'89 XJ Knuckles (getting harder to find, Ebay $100-$150 set)
-14mm drill bit to drill out the knuckle caliper mounting hole (Ebay) get drill necked down to 1/2" or need to use a drill press(safest)
-4 caliper mounting bolts 14mm 1.5 45mm (BoltDepot.com)
-12 washers 14mm 10.9 steel (BoltDepot.com) (2 washers used for spacers per mounting bolt 0.18" thickness)
-calipers and brackets- Centric 141.58009/10 Durango/Grand Cherokee '11-'15 for 330mm rotor (or equivalent) (RockAuto.com)
-rotors- Centric 120.65082 Sport Trac front rotors (RockAuto.com) (need to make the wheel hub smaller diameter to fit inside these rotors, easily done with flapper wheel)
-pads- Centric 300.14550 semi-metallic (or your favorite compound)
-Banjo Bolts for brake lines- M10-1.0 Mopar 06508914AA -banjo bolts, Mopar 06502114 -copper washers for banjo bolts and hose
-Dorman 12709 speed bleeders M10-1.0x35mm- Love these for bleeding brakes!! (optional) Calipers come with regular bleeders

This is basically the 'WJ Brake Upgrade' without the welding, new WJ lower ball joint, new steering, relocated track bar axle bracket and new track bar, relocated sway bar mounts.
The WJ upgrade is very $$$$ and labor intensive.
This DIY 15" BBK is easy bolt on. Uses stock or your upgraded XJ or 1ton steering, stock trackbar location.

All this bolts on, retains your stock or upgraded steering
Total cost of 'DIY' 15" BBK is about $500.
And you are getting NEW rotors, calipers and pads.
So if you are needing a front brake job anyway, this is not much more for the 12" rotor upgrade.
PLUS it eliminates the 'gouged' brake pad sliders and sticking front brakes that most all high mileage knuckles have.

Parts alone for a stock front brake job can be $150-$200 with rebuilt calipers, 11" stock rotors and pads. Then you most likely need to weld or replace your gouged brake pad sliders/knuckles, $50-$250.

It's not for everyone but it is just another BBK, Big Brake Option available.