Power Wagon front locker install

[R.D.J.]

I've searched regarding this, but cant come up with some definitive answers.

I have a 2018 Ram 2500 6.4 with the 9.25" front and 11.5" rear AAM axles. I ordered the trucks with 4.10 gears, as I knew i would put larger tires on.

I have a front axle assembly out of a 2018 Ram 2500 Power Wagon. My intent is to install the center section into my truck, and re-use my ring gear onto the Power Wagon carrier. I've read some conflicting reports of using a spacer behind the ring gear, and having to grind the adjuster lock.

I believe my differential housing, to be the same as the Power Wagon, aside from the Articulink setup on the radius arms. Since my factory gear ratio is the same as what comes in the Power Wagon, would I require this spacer?

I've asked my local differential shops, and they don't know.

I'm a mechanic by trade, and have done many differential repairs so this is nothing new to me. I would just like to have all necessary parts available when I do this swap.

 

[gtomike60]

Why not just swap the front axle assembly?
The Power Wagons have had 4:10 gears in them since 2014,plus there's the locker electrical connector that comes through the top of the center section that your diff doesn't have

 

[62Blazer]

I was going to ask the same thing as to why you wouldn't want to just swap the entire assembly? Maybe there is something else wrong with the PW axle you have, or maybe you don't actually have the complete assembly? I understand wanting to have all the parts on hand, but what about just pulling the covers off both axles and taking a look and take some measurements? Granted it would require a little duplications of work on the existing axle with pulling the cover and replacing, but may be worth it. At least pull the cover off the PW axle and see how it is set up. Guessing the whole spacer idea is based on the older PW's having 4.56 gears and maybe the carrier mounting height is different (thick vs. thin gear sets). I don't know for sure but would be surprised if you needed some sort of spacer between the two trucks. As mentioned above the PW has used 4.10 gears for years and would be and can't imagine that Ram would specify unique gear sets or require extra parts (i.e. spacer) for this, but again not 100% sure.

 

[R.D.J.]

Thanks guys.

Reason I dont swap the whole axle, is due to the fact it was in a collision, and the axle tube is bent slightly on the passenger side.

Ill disassemble the PW axle and see what I find.

 

[R.D.J.]

Ok, so I have just completed this swap in the 9.25 front axle of my 2018 Ram 2500 6.4 Hemi.

A few things of note:

I ordered my truck with the 4:10 axle ratio, and the 2018 Power Wagon donor front diff assembly obviously is 4:10 ratio as well.

The Power Wagon ring gear is wider (thicker) than the non PW 4:10 ring gear. Originally I had wanted to retain my existing ring and pinion, but I had to swap over the ring gear along with the locker carrier assembly. You cant get enough travel from the adjusters to get the backlash set correctly using a non PW ring gear on a PW locker carrier assembly. I suppose you could source a spacer that would go between the ring gear and carrier, but I didn't have, and was on a time constraint. I swapped the gears as well as the carrier. I had read that this or a spacer would be required for the 3:55 gears, but I ASSUMED the physical gears would be the same as a non PW truck. I was wrong, and so was the Chrysler parts lookup I used before I attempted the swap. It listed the ring and pinion the same between PW and non PW trucks.

I used the donor diff cover and drilled a hole in the roughly 10 o'clock position. I used a plug that is the rear diff fill/check rubber plug for a 2006 Ram 1500 rear differential. I drilled the hole the same size in the diff cover and two pin holes in that plug to run the wires through. I used a connector outside the differential, and wired it up to a 6 gang switch (similar to Spod switch systems). It works very well, and locks up instantly.

If anyone is contemplating doing this swap, its really quite straightforward. You just have to be mindful as to what type of gears you're installing/swapping.

The passenger side axle seal has to be replaced, because the stub shaft wont come out of the diff carrier enough. I used a seal driver and a long piece of threaded rod to draw the new seal into place. If you're swapping into a 9.25 AAM without the axle disconnect, this wont apply.

Sorry, I don't have any step by step (or any at all really) pictures, as I was in a bit of a time crunch getting this done.

If anyone has any questions, please don't hesitate to ask.

 

[Travelin Ram]

Thanks for sharing the solution.

Now I know who to call if I decide to regear mine.

 

[R.D.J.]

A re-gear should be pretty straightforward. Alot of people are afraid of differential and gear setups. I do quite a bit of them. Im a heavy duty diesel mechanic by trade, and have done many many differential overhauls. This one was a new one for me. Just figured Id share what I found, as there is not a whole lot of information out there. I really wish I had taken the time to take pictures. Maybe on the next one!

 

[62Blazer]

Thanks for the information. I am somewhat surprised about the thin vs. thick ring gears used between the axles. Guessing the PW front are low enough volume it made sense to get a different ring gear versus changing the carrier height on the locker assembly....or maybe there is some design parameter of the locker that wouldn't allow it????
You mention just swapping the ring gears. Did you keep the existing pinion gear and just swap the different ring gear in? I know it's usually not recommended to switch ring and pinions.....people usually will say how it will randomly explode and kill a bus full of nuns if you do..... Though on a front diff that likely has very little wear and will see very few miles under power I'm not sure it it's really a big deal..

 

[crazy jerry]

aam site shows different part# for pw and regular truck 4.10 because pw is thicker gear like you said

Ok, so I have just completed this swap in the 9.25 front axle of my 2018 Ram 2500 6.4 Hemi.

A few things of note:

I ordered my truck with the 4:10 axle ratio, and the 2018 Power Wagon donor front diff assembly obviously is 4:10 ratio as well.

The Power Wagon ring gear is wider (thicker) than the non PW 4:10 ring gear. Originally I had wanted to retain my existing ring and pinion, but I had to swap over the ring gear along with the locker carrier assembly. You cant get enough travel from the adjusters to get the backlash set correctly using a non PW ring gear on a PW locker carrier assembly. I suppose you could source a spacer that would go between the ring gear and carrier, but I didn't have, and was on a time constraint. I swapped the gears as well as the carrier. I had read that this or a spacer would be required for the 3:55 gears, but I ASSUMED the physical gears would be the same as a non PW truck. I was wrong, and so was the Chrysler parts lookup I used before I attempted the swap. It listed the ring and pinion the same between PW and non PW trucks.

I used the donor diff cover and drilled a hole in the roughly 10 o'clock position. I used a plug that is the rear diff fill/check rubber plug for a 2006 Ram 1500 rear differential. I drilled the hole the same size in the diff cover and two pin holes in that plug to run the wires through. I used a connector outside the differential, and wired it up to a 6 gang switch (similar to Spod switch systems). It works very well, and locks up instantly.

If anyone is contemplating doing this swap, its really quite straightforward. You just have to be mindful as to what type of gears you're installing/swapping.

The passenger side axle seal has to be replaced, because the stub shaft wont come out of the diff carrier enough. I used a seal driver and a long piece of threaded rod to draw the new seal into place. If you're swapping into a 9.25 AAM without the axle disconnect, this wont apply.

Sorry, I don't have any step by step (or any at all really) pictures, as I was in a bit of a time crunch getting this done.

If anyone has any questions, please don't hesitate to ask.

. aam site shows different part# for pw and regular truck 4.10 because pw is thicker gear like you said.
by chance did you notice how tall the machined OD portion of the pw carrier was ,were the ID of the ring gear slides onto ?

 

[R.D.J.]

To answer a couple questions here:

I did not swap my pinion gear. It had the same cast markings as the one as the power wagon. I know what you're saying on how they should be replaced in sets, but my truck has such low mileage, and so did the donor PW, I opted to use my existing pinion gear. Pinion and ring gears are sold separately on Eaton highway tractor differentials and power dividers, and as long as they meet spec, they're good to go. I've replaced many, many of them and the bus full of nuns has all been safe. I ALWAYS check the pattern after replacing rings, pinions, side bearings, pinions bearings etc, and this was no exception. Good pattern lets me sleep well at night.

Crazy Jerry - I didnt really take note as to how thick the OD of the carrier was. It seemed to be very similar to my factory open diff I removed. I had my existing non PW ring gear bolted up to the PW carrier and it had the same type of light interference fit as my factory carrier, so I would have to assume they were designed to be the same. Problem was, I stripped the PW diff down to the carrier and removed the ring gear the weekend before doing the swap. Once I did the work on my truck and had both carriers on the bench, It was clear the PW carrier flange where the ring gear bolts to was maybe an 1/8" or so taller than the factory open diff, when the drivers side bearing/race was on the bench. I should have looked at AAM's website instead of the crappy Mopar parts lookup I was using. I lived and I learned.

The biggest takeaway from this, is that you MUST have either the factory PW ring gear if your truck is 4:10 or have a spacer if the truck is 3:55. If you're regearing anything other than that, I'm simply not sure what combo would be required.

There are two main specialty differential shops in the city near me, and neither one had dealt with this. Guess its not as common of a request than what I thought it would be. Especially being its a frozen wasteland here for half the year.

 

[crazy jerry]

To answer a couple questions here:

I did not swap my pinion gear. It had the same cast markings as the one as the power wagon. I know what you're saying on how they should be replaced in sets, but my truck has such low mileage, and so did the donor PW, I opted to use my existing pinion gear. Pinion and ring gears are sold separately on Eaton highway tractor differentials and power dividers, and as long as they meet spec, they're good to go. I've replaced many, many of them and the bus full of nuns has all been safe. I ALWAYS check the pattern after replacing rings, pinions, side bearings, pinions bearings etc, and this was no exception. Good pattern lets me sleep well at night.

Crazy Jerry - I didnt really take note as to how thick the OD of the carrier was. It seemed to be very similar to my factory open diff I removed. I had my existing non PW ring gear bolted up to the PW carrier and it had the same type of light interference fit as my factory carrier, so I would have to assume they were designed to be the same. Problem was, I stripped the PW diff down to the carrier and removed the ring gear the weekend before doing the swap. Once I did the work on my truck and had both carriers on the bench, It was clear the PW carrier flange where the ring gear bolts to was maybe an 1/8" or so taller than the factory open diff, when the drivers side bearing/race was on the bench. I should have looked at AAM's website instead of the crappy Mopar parts lookup I was using. I lived and I learned.

The biggest takeaway from this, is that you MUST have either the factory PW ring gear if your truck is 4:10 or have a spacer if the truck is 3:55. If you're regearing anything other than that, I'm simply not sure what combo would be required.

There are two main specialty differential shops in the city near me, and neither one had dealt with this. Guess its not as common of a request than what I thought it would be. Especially being its a frozen wasteland here for half the year.

i was refering to this landing height. not the carrier flange face thickness

 

[R.D.J.]

Understood.

I didn't measure it, but when I had both diff carriers beside each other on the bench, in similar fashion to your picture, I noted that they were very very similar to the naked eye. Like I said, i didn't measure it, but it looked to be the same between the two.

Between the two crown gears, it simply appeared that the crown gear was thicker on the carrier flange side. Instead of a spacer, that space was taken up by the gear itself.

 

[crazy jerry]

Understood.

I didn't measure it, but when I had both diff carriers beside each other on the bench, in similar fashion to your picture, I noted that they were very very similar to the naked eye. Like I said, i didn't measure it, but it looked to be the same between the two.

Between the two crown gears, it simply appeared that the crown gear was thicker on the carrier flange side. Instead of a spacer, that space was taken up by the gear itself.

i only ask because if a guy were to use a spacer it may take up all that machined portion and leave the ring gear with nothing but the bolts as a locating mechanism. but if its nearly 1/2" tall it should be fine

 

[R.D.J.]

That definitely makes sense, and is a very good point.

I would not want that space taken up by a spacer, and not have the ring gear supported by the carrier.