Repower & Axle Swab for more speed

[sdobson]

Hi all,

I have spent several hours searching to see if someone else has already answered my question. I'm sure someone has gone through what I'm contemplating, but I can't find it....so I'm just gonna ask this can of worms questions.

I have a 1950 B-2-PW that my father and I are working on restoring. I want to be able to use it and eventually it will end up in Dallas TX....people drive like lunatics here. I want to be able to go faster than 45....and stop in a reasonable distance so we started looking at repower, higher gear ratio axles with more modern brakes....

The 230 is in need of a complete rebuild. It hasn't run in a couple of decades. Instead of doing the rebuild we have a running 360 and NP435 tranny from a 1985 Dodge D250 2WD and so we decided to do a repower. Next we started looking for a NP205 differential. So far so good. The piece of the puzzle that is giving us fits and the actual question in this rambling post-----

Does anyone know which axles we should be looking for that have close to the proper width and the correct front differential location? We thought we had a donor set from a 1995 Dodge 1500 4WD, that won't work.

Any help would be greatly appreciated.

Scott Dobson

[Matthew Welcher PWA]

Scott, Check out Greg Coffin's 6x6 here under the Power Wagon Forum, also Desoto61's Truck on this page, Take another look over at the Carryall Forum here. Many of these guys have done Engine and axle Swaps, Many will join in here and tell you what has worked for them. From my Experience the stock Power Wagon axles with 4.89 gears a 360 and an older Hydraulic clutch bell housing set up work very well for a Power Wagon. 60-65 mph with 37 inch tires works very well. As far as what other Axles will fit correctly as far as width, I am not positive. Welcome and please keep in touch as your project comes along.

[Desoto61]

I left the stock axles under my truck swapping them for the 4.89 gears, and I need to up-size to 37" tires (35" now). It's not as low a gearing as I would want considering I have the diesel which doesn't rev like a gas engine. With a NV4500 OD it would put highway speeds at just about the right 2100 RPM for most gas engines. My 4BT likes it about 300 RPM lower than that. Otherwise I'd probably prefer about 4.30:1 ratio if I could do it, but only way that can happen right now is to swap axles.

The main reasons I kept the stock axles were that I didn't want to get into steering modifications and IMO the Chrysler axles are one of the three things that make a PW unique, but mostly really wanted to keep the look of the stock BUDD wheels.

After building my truck I tend to prefer the idea of just doing a frame swap once you get to the point of deciding to swap the axles as well as the engine/trans. I don't think it's any more or less work to set the PW body on a later frame than it is to stuff all the modifications under a stock body/frame and you get a drivetrain that was factory designed to work together at the speeds you want it to go and is much easier to order parts for since you don't have parts from about 12 different year/make/model vehicles all stuffed under the same truck (like I do).

There was an article in the PWA a while ago where someone talked about a DANA front from (I think) a Ford 250 of certain years was best for the front as far as width and spring mounting locations, but don't remember specifics. I'd think there would be somewhere online you could find width measurements for different DANA axles. Though once you go with a more modern axle you can also more easily hide track width changes by buying the right rims and changing the offset.

I will admit that for the price of upgrading my axles with 4.89 gears and disk brakes I could have had a custom set of modern axles built by one of the companies that do so, but probably not that would support the BUDD lug pattern. I've seen a few trucks that have custom adapters but I have no idea how much those would cost to have made.

[sdobson]

Thanks for the help guys. We just got started, so we have a long way to go. I'll post some pics along the way.

Scott

[Jeremy Horvath]

Greetings from Dallas

Hey, Scott. I’m in Dallas myself. Traffic is deadly out here, that’s for real.

One option is to switch to a centered differential axle from one of a couple models of Dodge, such as the (m-43?) ambulance. Then, you can use a 4.89 gear set in both front and back.
I have a centered axle and a used differential with a 4.89 gear set that I was planning to use in the future but that day just might not come after all. I have made tools to work on these differentials and have successfully installed a locker in our B3-PW.

You’re welcome to contact me if you’d like.

Jerem
69
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[Jeremy Horvath]

BTW:
The reason for going to a centered differential when repowering is to mitigate the extreme likelihood of shearing the short axle shaft. Oddly enough, this typically happens when you ease into reverse. An engine with much more torque than the flat six can make it virtually mandatory to carry spare axles and hope that it breaks in a manner that makes it easy to remove the pieces. Ask Matthew about this!

[Matthew Welcher PWA]

I have witnessed many rear broken axle shafts, Just recently I have had my hands on custom rear axle shafts of a 2 piece design, salt bath hardened, beautifully designed to replace the stock Power Wagon rear axle shafts.

Hopefully with these and the RCV front axle shafts my hope is to see more repowered Power Wagons that will retain stock axle housings beneath them.

Alot of knowledge can be found on this forum, I am excited to see your truck progress and morph into it's new life.

[W_A_Watson_II]

I'm getting good at replacing them in my M37, not that I want too. Hopefully my re-powered PW won't break one.

[Matthew Welcher PWA]

I Believe the Missouri Mule may not see quite the terrain and use that Frankie does :)

[W_A_Watson_II]

I Believe the Missouri Mule may not see quite the terrain and use that Frankie does :)

Oh so true, but that Automatic has the potential to multiply torque.

[laddy]

Dosoto is correct in that it probably is about the same amount of work to frame swap as it is to axle swap. I'm doing the axle/power train swap and the rear end is easy just about any modern hd axle will fit you just have to move the spring perches. The hardest part about this is removing the old ones that are cast and welded onto the tubes. I ended up finding a aam 10.5 (14bolt) with disk brakes/ parking brakes and a limited slip for 200 bucks. I believe that you want a axle roughly 68 inches wide and spring perches at 44 inches, I can check the measurements for you in a few days when the snow melts.

For the front axle it comes down to if you are going to use the factory winch or not. If not you should be able to use any axle from 70-90s( half tons will be dana 44s 3/4 and 1 tons will be dana 60s) as long as it matches with what side your transfer-case drop is. If you are wanting to reuse the factor winch (I think it is one of the "characteristics" of a power wagon) then you need a passenger side drop transfer case and a passenger side drop front axle. these came in ford and chevy trucks up till 93 for dodge and chevy till 87. If you are going to do this I would recommend going with a 8 lug axle and then running a dually rim to get as close as possible to the original look of the power wagon as you can while having upgraded brakes and more friendly gears.

If you are going to do a custom axle I would recommend starting with a superduty front out of a 05 and up (a different bolt pattern than the standard 8x6.5 but more "current"). They are about as strong as you can get for the price( usually sub $400). This will be a driver side drop as are all trucks after 93 to just keep that in mind.

[sdobson]

Thank you for all the help guys.

I ended up buying a 1985 Dodge D250 as a donor truck for the axles, transfer case etc. Well all seemed good until we got to the springs and spring hangers.

The FFPW sits 4" low in the front and on inspection the original front springs had some damage and were repaired. In addition, the spring hangers are severely damaged. So.....we had a thought to put the D250 springs under the FFPW on the original FFPW frame. Well not so easy. The D250 springs are wider than the original and we'd need to fabricate hangers.

Every solution creates a corresponding problem. I'm starting to see why you either stay with nearly all original drive train or put the body on a newer frame.

[Desoto61]

Thank you for all the help guys.

Every solution creates a corresponding problem. I'm starting to see why you either stay with nearly all original drive train or put the body on a newer frame.

Yep, gives you an appreciation for just how complicated even these "simple" trucks are. Building a well-designed, cohesive vehicle out of bits and pieces will make you an expert in areas of automotive knowledge you probably didn't even know existed. Plus until it's actually drive-able there's not many ways to know how it will work in the real world.

[Alxj64]

Thank you for all the help guys.

I ended up buying a 1985 Dodge D250 as a donor truck for the axles, transfer case etc. Well all seemed good until we got to the springs and spring hangers.

The FFPW sits 4" low in the front and on inspection the original front springs had some damage and were repaired. In addition, the spring hangers are severely damaged. So.....we had a thought to put the D250 springs under the FFPW on the original FFPW frame. Well not so easy. The D250 springs are wider than the original and we'd need to fabricate hangers.

Every solution creates a corresponding problem. I'm starting to see why you either stay with nearly all original drive train or put the body on a newer frame.

What about just have new front springs made? I just ordered a set of custom 1.75" wide rear springs designed for my loads and application from Alcan for under $700. They have the correct pin ID and everything to use with the stock frame on my truck. I did pull the body and and box mine though, and it was amazing the torsional rigidity that everything gained.

Personally, and take it with a grain of salt, I'm yet to see a body to frame swap that didn't have mess of problems that the builder didn't solve by going "meh, close enough" and leaving something "not quite right". It devalues the vehicle, otherwise why wouldn't Precision PW and Legacy do body to frame swaps for modern stuff?

Yep, gives you an appreciation for just how complicated even these "simple" trucks are. Building a well-designed, cohesive vehicle out of bits and pieces will make you an expert in areas of automotive knowledge you probably didn't even know existed. Plus until it's actually drive-able there's not many ways to know how it will work in the real world.

^ This is so true! Which is why its hard for most people to wrap their head around the concept that a well built, safe, and proper performing resto-mod chassis sells for $150,000 or more. Details like sizing the master cylinder, pedal, and calipers all correctly. Suspension mounting points and geometry, cooling system efficiency and clean routing of lines, wires, and linkages. Reinventing mechanisms to work with or around existing body lines... it sucks, but its also so much fun when it works out and pays off!

For the sake of the machine, and your final product, please don't cut any corners and exhaust as many options as you can before cutting things up and selling off parts.

Afterall, with building these trucks there is something that rings true.

GOOD
FAST
CHEAP

.... ^Pick two ....


Good luck on the project and post here often with questions, there are several resto-mod guys around here, Desoto, myself, Bruce in BC, etc etc.

We're here to help.

[DrPepper]

Alxj64 it should be "Pick one"...nothing's Fast or Cheap

or maybe "one step forward and one back...".
I fought the axle question for several years and finally put '79 Dodge axles under my TW-PW. Front disc, 10x2.5 drums w/parking brake plus 3.21 axle ratio instead of 4:89. All the brakes including the Parking are '79 Dodge. Parts are available anywhere, no special order. I cleaned up and used all the original springs as they were in good shape. The rear I moved the new axle spring pads to match stock everything lined up even the shocks. But the front needed to have the springs moved out so, new frame mountings. Note the (civilian axle) right spring mountings are a machined casting and part of the diff housing.
My '57 was hacked by the PO so I bought a rusted out '87 Ramcharger for the 318 engine & A/T, steering and anything else I could get. Glad I did. The steering column is modified '58 (thank you Ron) and P/S is '87, two tries to get that right. "Borgeson Universal Co." for Steering components helped.
I didn't use the '87's axles, that's another story.
"Lefthander Chassis" for drag link, odds & ends.
"Eaton Detroit Spring" for U-Bolts and some components.
Parking Brake bought a late model foot pedal and ran new cables. Time searching for lengths, brackets and connections.
"Spicer" web site has U-Joint cross reference and sizes then go to auto stores for purchase. I'm using my stock drive shafts and NP Transfer Case.
Built "Sliders" for the front springs as there was simply no way I could get a shackle to do what I wanted. Pressed in bronze bushings and new bolts w/grease fittings.
Back and forth in the driveway and it feels really good.
Just installed new shifter for the 727 and working on wiring.
Maybe I'll get it on the street this year.
Hope this helps...
DrPepper