Disc brake conversion on M38A1?

[MASH 4077]

Has anyone ever done this and if so what parts/ mods do you have to do to achive this? Any help is appreciated!

 

[MO MV man]

I did it to my '71 CJ5 several years ago and merely took all the parts from a spare later-CJ axle my brother had laying around.
It was very straightforward, if memory serves me right.
If you don't have access to an axle to swipe the parts from.......have you looked online for the kits?
They're out there and surprisingly reasonable.

 

[MASH 4077]

Found one on Jungle Jim's Jeep parts for $785.00 and thats all the parts. Seemed a little steep to me. I wasn't sure if there were any later model CJ5's that came with disc brakes that you could swap onto the military axle.

 

[MO MV man]

It's just a Dana 25, right?
I believe I took all the parts off of a Dana 30 (don't quote me on that) from a mid-70's CJ5.

If memory serves me right, there are less expensive kits out there.
I'll message you the info this evening after work.

 

[MO MV man]

I just sent you a PM.

VERY complete kit for $570.

 

[quickfarms]

Why do you want disc brakes? The 11" brakes on mine stop great.

 

[MASH 4077]

Stopping power. Even with non-power disc brakes it would stop better. Also parts would be more availible. I believe the kit I looked at had a GM truck calipers and used GM brake pads, which are readily availible. Instead of having to find brake shoes or trying to find a place to re-shoe them.

 

[BillF]

One thing to think about is it might not work with your stock wheels.

 

[quickfarms]

The factory brakes are 10" and they leave a lot to be desired. My M38A1 has 11" drums on it, they use ford truck parts and stop as good or better than my jeep TJ that has power discs on it. This includes when I am towing the M100. The nice thing about the 11" drums us that the jeep looks correct. The only advantage of the discs is they are better if you take the jeep swimming.

If you want to talk about stopping power drums are superior due to their larger contact area. Look at 18 wheelers they use drum brakes, it is only the current ones that have started to show up with discs as an option on the front axle. There have been a lot of issues with discs on 18 wheelers.

I would stick with drums and install 11" drums on the front axle.

My hot rod jeep with the kenne bell V6 in it has 11" drums front and 10" drums rear, if you stomp to hard on the brake pedal it will lock all four wheels and it is not power.

 

[MASH 4077]

The kit I looked at said the factory wheels would clear the calipers. So that is not an issue. quickfarms, I'm probably comparing apples to oranges, but yes drums do have more surface for stopping, but with drum breaks they are pushing out to the drum as apposed to disc brakes having the caliper squeeze the rotor. I had a friend of mine that had swapped his drum brakes out to disc brakes on his 68 Cougar and there is a huge difference in stopping. The car stopped a lot quicker. I have also have a 64 1/2 Mustang. It has drum brakes and it doesn't stop near as good as the Cougar. Another thing is having to adjust both drums so that you get equal braking. I'm also looking at ease of doing a brake job. I can swap out brake pads in 30min or so. Drum brakes to me are a pain in the rearend. I guess its just to each their own.

 

[Dodge man]

This topic has been WELL covered in the Jeep forums such as earlycj5.net. You should check there for all the gory details. There are a lot of ifs, ands and buts regarding which wheels will fit, proportioning valves,etc. Most people are using d brake parts from Ford or Chevy trucks since they're a lot easier to come by and cheaper.

 

[MASH 4077]

Here is the conversion kit that I was interested in. The only thing that it says you may possibly have to do some grinding on the steering knuckle and its pretty straight forward on install.

http://shop.rp4wd.com/product/kits-disc-5

 

[quickfarms]

The kit I looked at said the factory wheels would clear the calipers. So that is not an issue. quickfarms, I'm probably comparing apples to oranges, but yes drums do have more surface for stopping, but with drum breaks they are pushing out to the drum as apposed to disc brakes having the caliper squeeze the rotor. I had a friend of mine that had swapped his drum brakes out to disc brakes on his 68 Cougar and there is a huge difference in stopping. The car stopped a lot quicker. I have also have a 64 1/2 Mustang. It has drum brakes and it doesn't stop near as good as the Cougar. Another thing is having to adjust both drums so that you get equal braking. I'm also looking at ease of doing a brake job. I can swap out brake pads in 30min or so. Drum brakes to me are a pain in the rearend. I guess its just to each their own.

Drum brakes are available in multiple diameters and widths. Jeeps have been sold with 9", 10" and 11" drums at different times. The brakes installed on a car or jeep are specified based on stopping power, pedal pressure and cost.

I know several engineers that design vehicles for a living and they have told me that the reason cars have disc brakes has more to do with public perception and marketing than actual performance.

Just saying discs are better because your friend swapped his cougar to discs and it stopped better than your mustang with drums is not taking into account all the variables with both vehicles.

As far as changing the brake shoes or pads goes, this only happens about every 50 thousand miles or so and is not that big a deal. I have had more issues with calipers sticking and taking out pads and rotors than adjusting drum brakes.

 

[MASH 4077]

Can we just agree to disagree? lol