Is This Really NECESSARY??? 4x4 Swap Begins 

The rear brake proportioning valve is necessary on pickup trucks because when there is no weight in the bed the rear tires would be more prone to locking up during hard braking. That valve will give more brakes to the rear tires as the suspension gets more compressed. If you lift the rear you should also add an extension to the valve so it still operates properly.

I Always remember hearing Vice Grip Garage say, "make sure to leave the jack under the vehicle, makes it easier to lift the vehicle back off when the first responders show up", especially seeing you use Harbor Freight jack stands like the rest of us "budget builders". Lol

It's so refreshing to see someone working old school, with a floor jack and jackstands! I never had a lift and really appreciate someone who works well without one. Love your channel! How about an update on your little brother's truck?

@Rudys Adventure and Design BE SURE TO MOVE THE SPRING PERCHES! You mentioned mounting the XJ rear axle under the springs to lift so I wanted to mention you absolutely need to move the spring perches, the springs will sit down and bolt up on the XJ ones but they are about 1"-2" off and will bind like crazy. Many people have attempted it and it doesn't work. If you do lift in this way, after moving the perches, simply turn the lower shock mount/spring plates over and switch sides to bolt your springs on and maintain the shock mount, you can also continue to use the factory rear shocks by doing this. Also as many have mentioned already that brake "thing" is a rear proportioning valve. As weight is loaded in the bed it will add brake pressure to the rear brakes and give you less brake pressure when empty to avoid locking up the rear tires. There is a small metal rod that bolts to the diff cover and that arm you were moving. I would recommend keeping this if you plan to haul stuff with it but be sure to test to make sure the valve is still working. I'd post the procedure here but it would be too long. You can also bypass it if you'd like but I would only recommend to do that if you swap it to disk brakes or add a manually adjustable valve somewhere, I'm definitely not practicing what I preach here though. 3rd, it seems you figured out how to release the spare tire but for others interested, there is a tube in the gap between the tailgate and the bumper you stick the factory tire iron into and turn it to release the tire. It's basically a winch mechanism, and if you aren't going to use it, there are definitely people who would want a working one. Really any MJ specific part is quite valuable and hard to find so don't throw any of it out even if its broken. I'm sure you've already found it but find the Comanche Club forum online, plenty of good resources there and us Comanche guys are always sharing info and answering questions. Also a great place to buy and sell parts to other MJ owners. P.S. Also be sure to use the XJ coil springs, the 4wd coil springs will sit the front end about 1" taller than the 2wd ones.

Not having all the right gizmos and gadgets and still getting it done............perfect. I love your show Rudy! 🤙

You need to send the "Blueberry" over to your dad so that he can put 1 tons under it and add it to the "Fruit Fleet" with the Banana and Tangerine.

"This (brake clip) was rusted on." Those are fighting words in the rust belt states. When it comes off in one piece or comes off at all, that's not "rusted on".

The valve on the back is commonly called load-sensing or height sensing valve. It shifts braking bias backwards as the suspension squats, so as you add load to the rear it increases rear braking. The bar in the valve should roughly be in the 2 o'clock position at regular ride height, so you'll want to extend the rod that goes down to the axle after you lift it. There's also a bypass for the valve that sends full brake pressure to the rear if you have a leak up front which takes an extra bleeding step. Open a front brake bleeder while you bleed the rear (to simulate a pressure failure) and then close the front bleeder, bleed the rear again and then fronts as you would any other vehicle.

NGL, it hurt a little bit seeing that complete, rust free '96 XJ turn into donor.

@Rudys Adventure and Design @ 14:10 that is probably a mechanical brake force adjuster - there are spring loaded valves inside that in normal condition are not all the way open and the flow of brake fluid is restricted. If there is heavier load at the back of the car the axle gets closer to the frame, the lever moves and pushes the valves so that the flow gets less restricted.

Love the channel Rudy and that you are doing your own thing. One suggestion, my grandfather was a mechanic and I've now been working on cars and trucks for 50 years. He taught me to always put the tire I removed under the frame rail in case of jack or stand failure so I've been doing it ever since. Cheers!

That piece on the rear that you were questioning is most likely a brake proportioning valve. My Tacoma has one from the factory. When you lift the truck you will need to put a spacer of some sort to get the valve to work correctly. My lift had on in it from the kit factory, but since I’ve “modified” my lift I had to do the same to the spacer.

Hey Randy we have watched Matt for a while & when we saw you go out on your own I thought we would see how you do things & I must say I’m impressed. Your videos are not too long & spun out like many, you explain stuff without going overboard, you know when to fast forward repetitive tasks and your music isn’t crap. In a nutshell you are doing very well so keep up the good work & this New Zealander will certainly keep following you. 👍👏👏👏👏

I really appreciate how everything your video is about is complete in the single video. A lot of car channels do the whole cliffhanger thing and make it a 12 part series when it doesnt have to be. Keep up the great work man, really enjoying the vids.

Rudy, this is one heck of a DIY video; you're taking a lot of time (sort of) to like help a first timer. One. Haynes or Chilton? Two, you got to show the secret trick: 'hit the nearest hard thing first to skin a knuckle to save your knuckles from gouges later' part. At least that was my secret back in my day.

Lever is a brake proportioning valve. More weight in the rear end allows more brake fluid/force to the rear brakes. When empty less brake force to the rear brakes don't lock up.

MJ owners coming outta the woodwork! I love it!

that thingy you don't know is a proportioning valve the more weight you have in the back the more rear brakes you get its to prevent constant locking up of the rear wheels when unloaded or at least thats what i was told

Great video! Can't wait to see how this all goes. Watching all the other channels only see 1 ton swaps and such, so really looking forward to watching this one take place. I am assuming the Cherokee had a D30 front and a 8.25 rear which is what my '99 Cherokee has so am hoping to pick up some tips and tricks 😉. Always enjoy your video's so as always, can't wait for the next.

Jack stands and floor jacks. Lots of memories doing that back in the 60s. It always did the job. Thanks for the video! Good job!

MJ is one of my favourites so it is great fun watching you rebuild and improve it. Thanks for the videos, Rudy.

Thanks for the video Rudy! You guys build cool stuff so Im lookin forward to the build. Good luck! Thanks to the editing department whomever that may be🐾

Good work Rudy can't wait for the finished product. Loved your transport to the outside with the engine lift. Take it up Toquerville with flashbacks of the first trip with only two-wheel drive. I'm impressed with all the good help from your fans. I've done a lot of four wheeling in a two-wheel drive, but it's just a matter of time before the two-wheel drive gets ruined on a four-wheel drive trail. There is really no such thing as four-wheeling in a two-wheel drive.

Doing great Rudy!! Looking forward to seeing you get the axle swap done and going for a test drive!! 😁

Love Rudy’s videos dude is smart nothing’s ruined if he’s working on it.

Awesome Rudy!!!

Looking forward to seeing this build done! Keep at er!

Rudy vary awesome idea. Can't wait to see more videos on this build out. Keep up the great craftsmanship and hard work my friends. Fab On. Weld On. Keep making. God bless.

That is a load adjusting proportioning valve. It adjusts the amount of fluid feeding the rear wheel cylinders depending on load in the bed.

I truly appreciate you and your Channel Brother. I like how you explain everything.

That parts Cherokee sure looks nice

I love how I recently got an 88 Comanche pioneer 4.0 5 speed 2wd. Just got axles out of a 96 xj. This is meant to be. I already have a new Trans and tcase. Awesome content. Can't wait to see what u do with the Comanche.

Great work Robbie. God bless you.

All hail the flat bay and a jack! Nice work. You don’t NEED a lift they make things way too easy

Great video Rudy....like the way stuff is explained !!..... video shots and editing awsome !!

Simple, instructive and enjoyable. Thanks :)

Good work, Rudy !

My Comanche started out as a 2wd also. I swapped in an XJ 4.0 and Ax-15 and Rubicon T-case.

Looking forward to you putting everything back together

I believe you're going to want the rear springs from the XJ to put under the MJ so your alignment pin is on the bottom of the spring to make life easier on you all...we had to do what you all are doing on an 85 & that's what we wound up doing + then all's you have to do is buy a pair of 3" front springs or use the front springs from a ZJ (mid 80s- 90s Grand Cherokee) to obtain the 3" lift needed to level it out.... Can't wait to see what you all wind up doing with it 🤠👍

Can’t wait to see the Comanche lifted and 4wheel drive I always loved Comanches mine looked just like it same color but mine was 5speed

Rear brake proportioning valves are awesome. They went out of style when ABS came along, but I'm pretty convinced they helped a good bit. A pickup is a great use for one, but my VW Passat came with one, too. Definitely worth keeping.

dont forget the transfercase and trans plus 4 x 4 linkge

Nice work Rudy.

I’m enjoying the series so far! Love seeing the transformation

thanks for sharing!

Hey Rudy, Wayne from Cape Town, South Africa, we call that a load senser here, it is connected to the braking system, and assists when load is utilized.

Thanks Rudy !

I love this series of videos, I did a similar swap with my 88 Comanche. I put a ford 8.8 rear end though

The brake thing in the back I believe is a type of brake bias deal. The weight in the back changes bias. If I remember correctly.

Very good Start to the project Rudy it’s going to be Nice

Great job Rudy!

My grandpa had one of these in red. Had that thing forever. I’d love to have one of those

good job. looking forward to the next episode. digging the commanche.

Ohio here ! winter kills our trucks and cars would love to have something that clean to work on. Loving your channel someone said old school and that is what we do takes a little longer but we get it done. have to use what you have.

You'll make this Comanche a proper 4x4 Rudy can't wait to see it offroad great video thank's for sharing God bless ❤😉👍

I was not aware the 2 wheel drive Jeeps from that age had a solid front axle. I learned something new today.

Interesting , Thank You .

good job Rudy !

An awesome video. Thank you.

This video one of your best so far. Sound quality much much better.

You seem more relaxed and genuine in this video. Great job.

Thanks for sharing 👍😀

Enjoying watching this series since I'll have a similar project soon! Curious to see what you do with that transfercase /trans combo

Well done Rudy, old school by yourself, great job. Looking forward to the next video.

Good show! C-ya next time !

I really like your simplistic approach to running your own shop.

i got rid of my rear proportioning valve and installed a wilwood adju prop valve in the front after my 8.8 swap and its been GREAT

Excited to see that you are 4x4 swapping the comanche, mine Is on a 6 inch lift on 31x10.50r15s ans stands about where you said you want it when you put it on the jack stands

Nice to see that truck getting a new life and with 4WD.

Axle on the bottom of springs. Drive angle will change, Tail shaft might have to be longer ? , stroke on shockers myl be different. proportioning vale on brake line may need adjusting, sway bar links will have to be longer or drop rail monts by thickness of the springs. Hope this helps keep going loads of FUN.

Reminds me of my 1980 f150 step side. I put a bronco front and rear axle in. Lots of fun.

Back in my hot rod days when we put the leaf springs on top of the axle we called reversing the rear end (maybe they still do) my 57 Chevy had a reversed rear end extended spindles 411 gears and 50/50 muffler lift bars, the car was fun.

As said about the load sensing proportioning valve in the back, if the rod is missing from the arm it’ll hang down and provide absolute minimum rear bias (if the valve still works at all). I pulled mine out and am replacing the distribution block by the brake master with a Wilwood manual bias unit, fresh flare/ nut on the main line to the rear (deleted the valve’s return line) plus a slightly longer rear hose/ block mounted on the axle to feed the rear brakes.

If Mr. Roger's was a mechanic. Rudy's video have that same calming affect

That was Cool saving the Mantis !

One of your best videos. Good work

Great job brother can’t wait for the next episode

of course, it is necessary. It looks like a fun build. good editing. I like 15-30 minutes tops.

Good video thanks 👍

I'd love to build a Comanche. That's awesome Rudy

good job Rudy..

Very efficient , Rudy. That was real fast axle Pull

That is a rear brake portioning valve. It increases rear brake effort as the bed is loaded and the truck squats, and keeps the rear brakes from locking up if the truck is unloaded and light in the rear.

That was a clever idea to use the forklift with the engine hoist in front to move it around. I guess your shop motto can be find a way or make one. 😉

Proportioning valve for the rear brake system will flow more or less fluid/pressure when loaded or unloaded

That is a height sensing valve when the rear of vehicle lifts its reduces hydraulic brake fluid pressure to prevent rear brakes locking up .and skidding make it adjustable and set it by trial until no rear lockup

Good job Rudi!

👍👍👍👍👍, That looks like a fairly cherry XJ.....

Awesome content Rudy.

Rudy this was an interesting video and in my opinion 4 wheel drive is definitely a good idea for the Camanche. I am looking forward to next weeks video

Well done Rudy!

Good stuff Rudy! Keep the content coming!

On the first obstacle of the Rubicon Trail my 88 Cherokee ripped the left front brake line off. It being close to the master cylinder, I just clamped the line off and drove the whole first day with the E brake and very little brake pedal. Fixed it at camp that night but wow a few very sketchy moments that day.

Great job Rudy!👍👍👍🤟🤟

Take the calipers off the axle and hang them from the vehicle to avoid the brake fluid mess. I even pulled the rear drum assemblies with backing plates and hardlines off the rear axle, when I did the axle swap on my ZJ. No brake mess, no bleeding required, no messing with rusty e-brake hardware, etc. 👍

Keep them coming Rudy!!!

@14:15 My ‘89 Jetta had a similar setup. It allows more rear braking power if you had more weight in the back.

The more weight you have in the back it allows more braking force on the back axle

Was wondering where you went … excited about your new project. And I would not know how you are supposed to do anything!