M916 / MK17 Hybrid Build

So here is the M916 MK 17 hybrid I've started to build. I'm thinking of calling it the Prius for short. This is my first real input to this (or any other) website, hopefully I'm doing this pic uploading thing right. If so these are the original pics of the two donors and a chopped up pic of the final concept. So far the project is going pretty easy, the RBU frame is the same cross sect as the outer on the 916 and will slip over the existing inner with little fuss. The material handling crane runs beautifully on the hydraulic winches aux pump, and a gear change and air locker is destined for the front axle to match the rears. This truck will have fully selectable numbers of wheels drive 1-6. The winch is shown here moved behind the crane , but I'm on the fence on that. Thinking of moving it to the front for better weight distribution when there is a heavy load on the crane , or to pull myself deeper into a predicament. I had originally planned it for the back to pull my dumb but out of a hole if I got stuck, or to pull stuff up on a towed trailer as it was originally intended. Would enjoy your feedback. Ill post more pics as the build goes on, but Im slow so it will take a while to complete.
KJ

Should be interesting. Pete did something similar with an 818. Might be able to answer a question or two if ya ask nice! Keep the pics posting.

Looks promising! Keep us posted.

You already have the second cab?

WOW I can't wait to see this come together !!

Nice to see those MK17s put to use. Great project. I love it!

It looks like it should have been that way to begin with, I contemplated doing the crew cab on my truck but I got a divorce instead, much easier!!!

promodhotrod said:

View attachment 223930

View attachment 223931

View attachment 223932
So here is the M916 MK 17 hybrid I've started to build. I'm thinking of calling it the Prius for short. This is my first real input to this (or any other) website, hopefully I'm doing this pic uploading thing right. If so these are the original pics of the two donors and a chopped up pic of the final concept. So far the project is going pretty easy, the RBU frame is the same cross sect as the outer on the 916 and will slip over the existing inner with little fuss. The material handling crane runs beautifully on the hydraulic winches aux pump, and a gear change and air locker is destined for the front axle to match the rears. This truck will have fully selectable numbers of wheels drive 1-6. The winch is shown here moved behind the crane , but I'm on the fence on that. Thinking of moving it to the front for better weight distribution when there is a heavy load on the crane , or to pull myself deeper into a predicament. I had originally planned it for the back to pull my dumb but out of a hole if I got stuck, or to pull stuff up on a towed trailer as it was originally intended. Would enjoy your feedback. Ill post more pics as the build goes on, but Im slow so it will take a while to complete.
KJ

Click to expand...

Thanks for this post.

I have the same plan (I have the 916 now just need a MK17).

Please keep this thread updated.

Looking good, Would like to see the finished project. I figured a gear change would be needed but wasnt sure. The MK17 has planetaries right? HEMMT axle up front would be pretty sweet also but may be over kill!

Alredneck said:

Looking good, Would like to see the finished project. I figured a gear change would be needed but wasnt sure. The MK17 has planetaries right? HEMMT axle up front would be pretty sweet also but may be over kill!

Click to expand...

You would run into a ton of fitment issues with a Hemtt axle up front, the rockwell that is in the 916 is a 20k axle, plenty for anything you would ever do. Plus gears are readily available for about $500 for the front.

I am excited for this!

Whats the gear ratio on the MK17?

If you are going to do the crew cab using two regular cabs I would consider putting them back to back and have suicide doors since they are narrower at the front.

Looks neat, but be prepared for the turning radius to be about 500 feet or so.

Hello, and thank you for the input. A few answers to the questions:
-The MK17 has 58K tandem set with 5:57 gears and air lockers in both diffs with air engaged interaxle.
-The stock front axle is staying, just changing the gearset and adding an air locker.
- I'm not actually making a crew cab I'm putting a 36" aruminum sleeper behind the cab, I just cut a chunk out of the picture to get an idea on the proportions. Also the sleeper will hide a ROPS so everyone doesnt know I'm a chicken.
-Turning radius is a concern as the truck will be 34 feet long, but I'm figuring it wont be any worse than a LWB road tractor. I had originally planned for a 60" sleeper but shortened it to 36 to keep length down. The bright side of the long wheelbase is stability, espicially with a heavy load on the crane, as believe it or not the 916 is actually lighter than something, the FPU.
Not much new to add, got the donor running well and took it for a drive this week, no problems there so its into the shop next week to start disassembly.
Also wanted to add, that after driving the other (parts) 916 and the donor truck this week I am extremely pleased with the operation of the much maligned Cat 7155 trans. My worries over it are completely alleviated. To tell the truth I love to have this trans in my bus in place of the HT755 allison, as the allison has way to tall low gear in my opinion. These are the first road tractors I've actually liked driving. After giving rides I told all the guys at the shop this trans is where the F1 guys got their auto shift technology, but Im not sure they bought it
How about your thoughts on winch placement, front, rear, or off?
Thanks
KJ

front winch

KJ,
Looks like a neat project. I say go for the front winch. The stock front end grill guard and bumper on the 916/920 don't really match the stoutness of the rest of this truck. I'm not sure what the hydraulic winch with cable weighs but it's going to drop the front end a bit. Having a 7/8" cable on a drum that size on the front end says "This truck means business" Make sure to add a bumper that looks more like a C500 KW off road oilfield/logging truck.

like this
1994 KENWORTH C500 Winch/Oil Field Truck For Sale At TruckPaper.com

Andy

Having tackled this project myself, a little insight. First, why a winch? If you get into something so nasty that those lockers won't get you out, you have an awesome crane that works a LOT better than any winch, AND, it's "multi-directional". Check your rear gears, mine are 5.44:1. Do you by any chance have the A1 edition? I would also like to know where you plan on getting the gears for front end. Another note, if you are putting a 36" sleeper behind the cab, I think you will be longer than 34 feet. With just the oil reserve tank behind the cab, an using the stock driveshaft, mine is 34. Hopefully that 916 has a tighter turning radius than my 818. Good luck with the build. I use mine all the time....keep wondering what I did before I built it.

All I can say is I am in a state of SHOCK!!!!!
popacom

what about mounting the "box" backwards so the axles are closer to the cab, crane in front box in rear???? having a usable turn radius is pretty nice...

Awesome project, subscribed!

About your winch idea/question: I have always mush preferred that if you have only 1 winch that it go on the back just for the reason you mentioned (backing out is almost always easier than going in more/deeper).

Also... I would tend to agree, you have quite a bit of weight back there already another 750 pounds would not help much. If you did get stuck and wanted to go backwards the crane could be used with some caution. If you need to winch something closer to the truck to pick it up you could always just turn around (I know, a pain but....) Of course you could also just use the crane to pull it closer most of the time. My vote (Like I have any say so in your project...lol) Is winch on the front. But that is just me...

Please keep us posted with lots of pictures!

eldgenb said:

You would run into a ton of fitment issues with a Hemtt axle up front, the rockwell that is in the 916 is a 20k axle, plenty for anything you would ever do. Plus gears are readily available for about $500 for the front.

Click to expand...

I keep seeing people post that 916/920 optional gear ratios are readily available. I have made hundreds of internet searches, emails and dozens of phone calls looking for them. So far, I have found 1 set of used front gears and nothing else. Anybody with any real leads please PM me, I would greatly appreciate it!

oldMan99 said:

Awesome project, subscribed!

About your winch idea/question: I have always mush preferred that if you have only 1 winch that it go on the back just for the reason you mentioned (backing out is almost always easier than going in more/deeper).

Also... I would tend to agree, you have quite a bit of weight back there already another 750 pounds would not help much. If you did get stuck and wanted to go backwards the crane could be used with some caution. If you need to winch something closer to the truck to pick it up you could always just turn around (I know, a pain but....) Of course you could also just use the crane to pull it closer most of the time. My vote (Like I have any say so in your project...lol) Is winch on the front. But that is just me...

Please keep us posted with lots of pictures!




I keep seeing people post that 916/920 optional gear ratios are readily available. I have made hundreds of internet searches, emails and dozens of phone calls looking for them. So far, I have found 1 set of used front gears and nothing else. Anybody with any real leads please PM me, I would greatly appreciate it!

Click to expand...

With this kind of a build you will be using the winch for recovering someone or something else anyways, for the self extraction use the crane with a snatch block, works great. I vote for a front end winch off of a 5 ton, I took a lot of measurements on mine to mount the factory one to the front and it would take some serious fabrication to make it work and look appealing.