M37 Repower, Reaxle

[JeffTheMarine]

I am still in the planning stages for the M that I am going to be picking up at the beginning of next month. I am trying to find out as much info as possible so that I can start collecting parts.

I plan to repower the truck with a Cummins 4bt, NV4500, Divorced NP205 and am thinking of a Dana 44 front and Dana 60 rear.

First question is if someone has done this conversion did you use a driver or passenger drop transfer case?

Will I run into problems if I run a passenger drop Dana 44 with the exhaust and transfer case? I have looked into the idea of running a HP Dana 44 out of a Ford with driver drop. I want the truck to have 8 lug hubs so I will need one out of a 3/4ton truck. I would prefer not to contaminate my truck with Ford parts but If it is going to be a big hassle to run everything down the passenger side then I will bite the bullet if I have to.

Also has anyone installed the newer fiberglass tops that are sold through VPW? If so what kind of fit and finish did you experience with the parts? Are they really as easy to remove as they say they are? If possible could someone attach some pictures of one of their tops?

The main reason for doing everything this way is that I want a truck that I can drive everyday and the truck I am purchasing is literally just a frame and body so it's not like I'm ruining a good running M.

I appreciate all the help in advance from you guys and am looking forward to getting this project started.

Thanks
Jeff

[JeffTheMarine]

Also I have looked into the ugly truckling hanging pedal kits and they seem to be the route that I want to go. However I am concerned about being cramped inside the engine bay and with the brake booster that I have seen in pictures that people have installed it looks really large. Has anyone run a smaller brake booster with the Uglytruckling kit? If so what part numbers or what was it out of?

Thanks
Jeff

[Hemiman]

Not sure what your goals are, but if you are looking to get away from the M-37/PW specific axles, one of the best setups is the Corp 14 rear and Dana 60 front out of an M-1008 CUCV. This has the correct passenger side offset, and will also get you a Detroit locker rear. Also comes with 4.56:1 gears.

Driver's side drop will cause trouble if you want to use the Braden LU-4 winch. Also, if you can find an M1028A1 CUCV, you get a PTO NP205 (married). Advance adapters has a kit to bolt this up to your NV4500.

Otherwise, if you already have the Ford donor, you can make make those components work. It'll be a little more work however.

[Master Yota]

A diesel repower with the 4bt has been made to work with a passenger side drop axle, either the original axle, or a newer Dodge/GM D44 or D60. With the taller gearing of a modern axle, (4.10's) the stock NP200 should survive just fine. It'll turn slower at a given road speed and negate most if not all heating issues they seem to be prone too. The guts are virtually identical to an NP205, so its plenty strong enough to stand up to the diesel. If you're looking for a divorced NP205, then one from an International truck seems to be the holy grail, as it has a passenger side drop, with 32 spline inputs and outputs, making it the strongest divorced case that I am aware of. The Ford divorced tcase is the Dana 24, and Gm used a Rockwell T225 (IMS). Both of those cases are marginal at best when compared to the NP200 and the NP205.

As for brakes, there isn't much point running a vacuum booster with a diesel, as you'd need to add a vacuum pump to make it operate. You'd be much better off to go with a hydroboost system, its a smaller package, and runs off the power steering pump. They are easy to come by in most wrecking yard (looks for a GMC/Chevy Astro van or most older GM diesel trucks have one). I wish now that I had gone that route instead of installing the enormous vacuum booster in my truck. I may still change it out should I ever have to pull the engine out. It would also be very easy to run a smaller booster, simply drill whatever mounting hole pattern is needed in the pedal plate and go from there.

I second the 14 bolt over the D60 as a rear axle choice. Its much more user friendly, and its a bolt in requiring only a little grinding on the spring perches to make it fit.

Good luck with the swap, and take a lot of pictures for us image hounds...

[k8icu]

A Dana 44DF front out of a Late 70-mid 80's Dodge will work along with the Dana 60 rear will work. 4.10 gears. That too is a passenger side drop on the front axle. But dropping a modern axles into the truck is not a bolt out bolt in job. You'll need to modify either the front springs to set the axle in right or you will have to have the axle housing shorten to fit. On the rears you'll need to move the spring perches slightly to get them to sit right. It will look like the rear just bolts in, but it doesn't the rear leafs will be slightly pulled in if you don't modify the perches. If you want to see what I've done you can check out my project page here. http://leathernaturally.com/m37project.htm Please keep in mind that my truck is still in a gazillion pieces in the garage and hasn't been on the road yet. Sigh time and money never play well together...

It can be done and others have been successful, I just wanted to make you aware that it's not a drop in project.

[Master Yota]

The c14 is a bolt in affair, with only some clearancing of the spring perch required (its wider than the 2" wide spring, so the Ubolts won't clear the perch without some grinding) I can't speak about the Dana 60 rear, but the c14 didn't pull my spring packs out of alignment. The stock Ubolt plates also fit the 14 bolt tubes. Its about as close to a drop in as it gets.

The dodge D44 fronts of the late 70's and 80's had terrible wheel bearing design, and should be avoided. The bearings are small, and failure prone compared to other D44's. I will admit however, that I don't recall if this issue applies to all the D44 fronts, or just the half ton 4x4 trucks. Either way, its something to research before pulling the trigger. You could also look for an International D44 3/4 front - the diff is slightly more centered making for enough room to mount spring perches on the housing that'll match the M37 width. That would be the easiest way to go if you can find one.

[JeffTheMarine]

Does anyone possibly have any pictures of a 4bt with passenger drop axle under a M? If you go into the early to mid eighties on a front Dana 44 and get one of the non full time 4wd axles that you can unlock hubs on then they are fine to use. However you do have a very strong point on the FT4wd axles having garbage bearings. I have tried to rebuild them before and had nothing but problems with them. I have actually not purchased trucks because of those axles or immediately searched the pull your own parts yards for an axle with unlocking hubs and normal bearings. However if it looks like it won't be too much of a hassle then I would be fine with using a Dana 44 out of a Dodge. I am kind of a purist in that sense. MOPAR OR NO CAR BABY! (or truck I suppose......)

Jeff