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Old Apr 5, 2025 | 02:28 PM
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zip439
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Joined: Jul 2010
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From: SE Alabama
Default Re: Swap OEM differential for Mopar 3.64

This is the same as the pdf above
Specific directions when changing differential

This is for SRT6.

Limited, Base may be a little bit different.

If I where to do this again I would disconnect the flex disc at the differential flange, remove the rear exhaust pipes and muffler, disconnect the parking brake cables and then drop the entire carrier frame. It is only four bolts and then with it on the floor or work bench you have easy access to everything. I used the method below as it has been done by other forum members.

What I did do was disconnect the flex disc, drop the rear exhaust, disconnect the parking brake cables and passenger wheel linkage, only the lower control arm remained connected, drop the differential down, pull the passenger axle shaft out from differential and then remove the differential by pulling the driver side axle out. All the driver side links remained untouched. Fortunately I have a lift so I can get under the car. I wouldn’t attempt without a lift. As you work either put the bolt back in the hole it came out of, once the item has been detached, or label a zip lock bag and place the bolt in it so you will know where they will return when assembling.

Take off the wheels, put the car in neutral (if your are tuning the TCU & PTCM disconnect the battery and get them in the mail). Lift the car. Drain the oil out of differential.

Remove the brake caliper from the rotor and tie it up out of the way. I also removed the black plastic cover from the fuel pump and filter.

Remove the rear exhaust. My resonator had been removed years ago, but it is still long and with the bend it is awkward to deal with the weight. I strapped the muffler to the transmission jack and placed a roll away tool chest with a 6x6 piece of lumber under the end near the piping joints. I have a T handled hook about 13 inches long that I used to pull the two rubber connectors down and off the muffler. You have to have the entire piping fairly level to get the slip joint connection to pull apart. The donut style connection is much easier to deal with. Your piping may be different than mine. I know the Limited has a single pipe aft from the connection, but my SRT6 has two.

The lateral link (toe adjustment), trailing link, and track link I disconnected from the cars frame. They come apart a lot easier than going back together as the bolt is a very tight fit through the hole in the frame and the hole in the links bushing. The camber link I disconnected at the hub, and the sway bar link and shock absorber get disconnected at the lower control arm. The camber bolt is easy to strip at the head. Be certain your torx bit is completely inserted into the bolt head. I used a spring compressor to safely take tension off the coil spring while disconnecting the shock absorber and the sway bar link.

Loosen the bolts holding the flex disc to the differential. The pinion shaft of the differential protrudes about ½ inch into the flex disc so you must force the drive shaft forward to get the differential down. You will get 3/8 inch of free play by loosening the center bearing support bracket. The center bearing can then move forward making this easier. Notice the nuts on the flex disc are all on the rear. They do not alternate as in some setups.

The differential is heavy. You will need something to get under it and hold it for you. I have a transmission jack so I attached it to the jack before loosening the forward bolt and the two rear. Be advised there are steel washers and a rubber bumper/washer between the differential case and the cars frame at the forward bolt. Look at how they sit in relationship to one another.

When you get the differential down move the drive shaft to the side and disconnect the parking brake cables from the tensioner in the drive shaft tunnel. This may not be necessary, but they stretch tight when removing the axles and I did not want to take a chance in damaging them, so better safe than sorry.

When you get the differential down, you move it forward stretching both axles which are still attached. Twisting the differential and jerking it toward the driver side should get the passenger side axle out. Pulling and jerking toward the passenger side should remove the driver side axle. My passenger side came out relatively easy, but driver side got hung up. I spent three hours pulling jerking spraying penetrating oil on it but it would only come out about 1.25 inch. It was not hung up from the clip/ring. That had passed out. Something else had it stuck. I tried rotating the axle using a pipe wrench to reorientate the shaft to the differential but to no avail. Generally pissed off with the day, because that damn thing would not slide apart I went to bed for the night. Next morning I gave it a couple tugs and it came apart. Go figure. I did notice the axle shaft outboard from the splines had some scaring so before reassembly I polished both axle shafts with emery cloth.

Putting the new differential in was more difficult than the removal process. First I slipped the drivers side axle in, not too bad, but getting enough room to place the passenger side axle in the hole without scaring the new rubber seal was a strain. I finally got it in and I have no leaks, but it isn’t an easy lift it up there slip it in operation. I used the transmission jack to hold the differential while inserting the axles.

Reconnect the parking brake cables if you took them off the tensioner.

Now tilt the differential up in the front force the drive shaft forward and get it started by inserting the pinion shaft into the center hole in the drive shaft disc. You must also have the disc lined up so the bolt holes will match up correctly or the flange will prevent you from slipping the differential into place. This is why the car is in neutral so you can spin the drive shaft and get the bolt holes lined up.

Okay, that’s the easy part now you get to reconnect all the links and the coil spring. Fortunately pulling the lower control arm down gives enough clearance to put the spring back to it’s proper place without the use of the spring compressor. Line up the bottom of the spring with it’s indent in the lower control arm; the rubber perch sets where it fits at the end of the spring on the top. I put the track bar back together first then the camber, the lateral (toe adjustment) and finally the trailing link. Get the links up into their place before inserting the first bolt. If you start reconnecting without having the links into the frame you may find that you won’t have the room to move them into position. It went pretty good though lining up the track link and getting the bolt all the way through the hole had me talking to myself again. The trailing link had me talking to god, and the engineers. The service manual tells us to break the hub from the axle to get all this apart and connected again. Might be best to follow sage advice, but at this point I plowed onward. I did get the trailing link reattached to the carrier frame by inserting two lugs into the hub. Using one as a place to put a small bottle jack which was sitting on a 2 x 8 plank on top a trusty roll away tool chest, and the other lug to lever the hub forward and up to a position the trailing link could be reattached. That’s the trick. Use the lug with a 17mm socket and a breaker bar oriented so that the bar doesn’t flex at the head, but you use it as a solid lever forcing the hub forward and up so that the bolt can be run through the bushing.

Okay, now you get to connect the sway bar link and the shock absorber. Not too bad as I could raise the lower control arm up by using a high floor standing screw jack, insert the bolt and tighten it up.

Everything is hooked back up, but the toe is certainly way off. This job just doesn’t want to end. So about two hours later after using toe boards and a long straight edge I get the rear toe pointed in the right direction.

Now, reconnect exhaust piping.

If you got this far be advised I did all this with just my own two hands. Thankfully I have a well stocked garage and some experience. This is not a job to jump into without a bunch of tools, and some fortitude. It would help a lot to have an extra pair of hands with some muscle when lifting and twisting. Good Luck!
 

Last edited by zip439; Apr 5, 2025 at 05:51 PM.
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