Mods, if you could read through this and sticky this that would be great. There is currently and 9.25 swap in the FAQ, but it's for the drum rear and I have just got done doing my 9.25 swap with disc brakes. Which is quite a bit of difference. Without further Ado, here's the write up. (

My truck is a 96 Dakota long bed regular cab with 4wd automatic and a 5.2 Magnum. Months ago I acquired a 9.25 disc rear end with LSD differential. The reason for swap was to get disc brakes for future brake jobs, and to get rid of one wheel peel and get suretrac, posi rear end etc, whatever you wanna call it.

My drums were completely shot, and I don't work on drum brakes. And one wheel peels are never cool, so I found the rear end, and here we are.

I'm not going to do a drawn out write up as most things are straight forward, but more a list of things needed so people in the future can get everything prepped for when they do it.

Firs thing you'll need is a rear end with disc brakes. Make sure you open the diff to make sure you don't have a lemon. Mopar axles are c clips and are a weak point. (Though the 9.25 and even 8.25 are great axles.)

Next, you ABSOLUTELY have to have 16"+ wheels. Don't be like me and test fit 15" wheels and say it clears, only to find out when you have weight on the axle they rub and the truck won't move at all. I test fitted the 15" wheels I had and went through with the trade. Now one reason they may rub now, is I bought new calibers because one of them that came with the axle were froze. So small chance aftermarket calibers were slightly different in shape. (The rear end I got had 49k miles and factory calibers)

The next important thing you'll need is to get your drive shaft shorten exactly 1.5" since you're going from a u bolt strap to a flange set up. as well as getting what's called a bastard u joint to join your drive shaft to the flange add on. Call your local drive shaft shop and tell them what youre doing, and they should be able to pull it right up. You can't use the same drive shaft even if the truck you got the rear end from matchets your set up being the trucks with disc brakes have different spline counts at the transfer case/drive shaft. What I don't know is , is if the input shaft length is the same. So I don't know if you could use your shaft and swap both ends. Again, I just had mine shorted.


The passenger side shock mount needs cut and flipped around to match the drivers side.

New u bolts are highly recommend since once you take them off, they shouldn't be reused after being torqued down. Why risk the chance of snapping a ubolt because the nut didn't torque properly? Now, this is where I've seen a lot of very wrong info. Yes, the 8.25 axle has 3" tubes and the 9.25" has 3.5" tubes, but that's null and void being our u bolts wrap the leaf springs instead of the axle. So the right specs for the new u joints are 2 5/8 square, 8" long and 9/16 diameter. You could use 1/2 diameter and 7" long, but the first specs are what used. I had mine made brand new with nuts from a place that specializes in leaf springs and lift kits. They cost me $50.15 with tax for all four, and we're done in 5 minutes.

When you go get your new 9.25 rear end, make sure you get the u bolt plates. The 8.25 plates don't have the right radius to keep the 9.25 in place. There are multiple mopars that use 9.25, just make sure the vehicle you get them off of have the plates where your plates are now. (Spring over axle, or spring under axle)

When I filled the rear end up, i used lucas full synthetic fluid and a bottle of LSD additive. Sorry forget the weight of the gear oil right off, but basically use whatever your needs call for. Don't forget the new gasket or a tube of gasket maker.

Now would be a good time to get whatever brake stuff you want to replace. Minimum I would replace the brake hoses. The run about $20 a piece at the time of writing this. MAKE SURE YOU DONT LOOSE THE BANJO BOLTS!!! I Thought I did and you just can't walk in a parts store and buy new ones, and my rubber hoses didn't come with them.

As for the leaf springs, if you wallow out the the centering hole just a hair, they line right up.

Here comes the best part, the brakes:

After you get the flares made off your old hard lines and add fittings to match the new rubber lines and get them bleed, you're done! I'm using my stock master cylinder off my 96 that's set up for rear drums and after multiple hard stops,I've experienced absolutely zero lock ups.

Now, I will add I didn't do anything with the ebrake as I live in the rust belt in an area that doesn't have inspections and never use it anyhow. But there are sights to look up for that aspect of the swap.

And, I do have an brake light on, but I think I have that narrowed down to the anti lock brake sensor on the rear axles being different. It's connected there, but not sure if it's working right. Again, I don't care about anti lock brakes so not worried about looking into it.

Something to keep in mind though, disc brakes use more fluid as the pads wear down, so keep an eye on the master cylinder as the pads wear down. And when you replace the pads, take off the master cylinder cap so you don't blow a seal when you push the pistons back in.

As for now, there is nothing in addition on the brakes lines besides what's from the factory. Again, even without an adjustable proportioning valve, I have zero lock up even though I'm using a drum master cylinder. And I've tested them pretty good.

However, I probably will be adding an adjustable proportioning valve due to the difference in how drum vs disc brakes work. Drum brakes have a very slight pressure on the pads at all time. Without swapping the master cylinder, there will be slight pressure on the pads at all time. Which probably will cause undue wear and tear, as well as hear from drag. After I drive it some more, I'll determine if that is in deed the situation in real life.

At minimum, I plan on swapping the master cylinder to an 04 just for ease of mind. But have no plans on doing that any time soon.

Well, I believe that covers everything without obvious details. If there's any questions, ask and I will do the best I can to answer.

As a reminder, I went from one wheel peel 9" drum brakes that were shot, to an lsd with 11" disc brakes. If you have a 4x4, remember to get the right gear ratio to match your front

 

Freakin awesome man thanks for the info...down the line this might happen for me.

 

no problem. To my knowledge, I'm the only written source who has done this swap with a flange rear end. If anything is unclear or you want a short list lmk. Might even make a short list anyways tomorrow.

My second burnout the tires roasted for a good 35-45' lol. It felt great. Stayed straight as an arrow too. Big grin.

 

Glad to hear it worked out for you. How do you plan to adapt the 2004 master cylinder to the 96 truck? Looking at pictures, it seems to be a different design.

 

honestly, idk, it's just kind of a thought right now. I'm sure if I want to there's a way.

 

I have heard that the ford expedition master cyl works. The base that bolts to the brake booster looks closer to fitting than the jeep cyl. But again, I dont have any actual experience with it.

 

thanks. If when the time comes, I plan on just going to the parts store with a list of vehicles that have rear disc brakes and go from there. But again, no need to do it anytime soon.

 

Stuck. Thanks!

 

thank you!