"The Crummy" 2006 F450 fire crew buggy

[simple]

We recently sold our 2020 sprinter 4x4 camper conversion and found an old DNR fire crew bus to build out. It's a 2006 F450 4x4 V-10 with manual 6spd trans and 4.88 gears. Rear axle is a Dana s110 with limited slip. Weight with seats removed 11,260lbs, rear axle 7,160lbs, front axle 4,100lbs. The box is just shy of 8 ft wide, 12 ft long and 6ft ceiling height. The box has a steel frame and skin (complete with tree branch pin striping. my favorite kind). This could be set up nicely for cold weather camping by applying some 3/4 - 1" closed cell foam like K-flex on the interior. Add batteries and a diesel heater and be good to go. The box is mounted to the frame with springs front and rear and feels really solid (no creaking or wobbling back and forth). My initial impression is that I will be comfortable driving longer distances on fire roads without worrying about it coming apart.






SIDE DOOR


BOX INSIDE






The rear storage locker is 30" deep.



Built in 2cycle fuel tank with external fill. It's currently designed as a gravity system for filling power equipment but it could also be used as a diesel fuel tank for a cabin heater.

 

[simple]

DRIVING DETAILS

All in all It drives decently for an overweight, crusty 16 year old truck with 130k miles on it that carried loggers up and down fire roads. The turning radius is manageable. The noise and vibration is tolerable and will get better with new shocks and tires. The manual transmission doesn't have any major faults so far. Brakes straight and quiet. Overall it's fun to drive.

The transmission is 1, 2, 3, 4, OD with a granny gear. Turns about 3000rpm in 4th at 60mph and about 2300 in OD at 60mph.

 

[simple]

BUILD PLAN
Looking it over I've got a lot of different ideas on buildouts. The main criteria is seating for are a family of 3 with a dog that goes everywhere. This vehicle will be a weekend warrior with an occasional week thrown in here and there. I'd like it to be worthy of a couple months of traveling but that is a lower priority.

The cab has 40 20 40 seats and could work although I'm interested to find out what its like to ride in the box. If it provides a viable passenger space, I'll take all the bench seats out and install a 3 person 1st row seat out of a Sprinter bumping up the seating capacity to 5.

 

[simple]

I spent half a day removing all the seats and bits and getting the box swept out. I then took some measurements and started some 3-D noodling. After hours of moving shapes around I think this is close to what is going to work in there if I go with a design that retains passenger seating in the box. TBD Still need to go for a ride in the box.

The passenger seat will be a first row seat out of a sprinter van.

The kitchenette will be some kind of propane cook top, ARB fridge (already have one) and a sink serviced via plastic jerry cans for fresh and grey water. (I'm going to use it at our local mountain in the winter and I want a quick easy way to keep winterized when not in use.

Bathroom (haven't decided on the toilet system. They all have pluses and minus)

The L shaped dinette bench will convert to a full size queen and the overhead bed will drop down and be a half queen. I'm not a fan of convertible beds in general but I think it is the price to pay for a little bit of living space and keeping 3 passenger seats. There will be room under the bench for slide out plastic storage boxes. I like these over drawers so they can be packed in the house and easily carried out to the RV. Same for transporting stuff back in.

The rear doors will work as is and open up to a heated storage closet for storing and drying gear.

There will be a battery bank hung somewhere under the box along the frame. Mostly likely lead acid style.

There will also be a larger water storage tank for trips above 32F.

This build out easily works with the stock box configuration except for the divider wall that separates the back storage closet from the cabin space. It sits 30 inches in from the back doors and will need to be removed. It is designed to keep flammable liquids and heavy things out of the cabin and is built with 1" plywood skinned on both sides with 0.030" steel sheet.

 

[simple]

 

[OverlandFT]

Looks like an awesome project! I think your initial layout looks good for utilizing the space. Is that a half door on the driver side too? Do you plan on putting a wall up behind the bench seat for the bunk bed tracks? Since we have a trifold sofa for our bed (only thing that would fit), we use a pillow top and it makes it feel more like a mattress.

How's the v10 feel on this size truck?

Also, are you going to make the truck rear window a passthrough? My 6 year old daughter uses our passthrough a lot on trips and the dog lays on it while on the road. It's helpful, especially with a single cab!

 

[simple]

Thanks. Yep its a half door emergency exit. I'm not sure on the wall behind the passenger seat yet. I was thinking it might be a good idea to build some kind of a safety wall there and that could also double as a support for the bunk.
The v10 feels like it will get the job done although it would be a lot better with a Cummins diesel. We'll make it work though. I imagine my 6 yr old daughter and dog would enjoy passthrough as well.

 

[simple]

I had a friend drive it down the freeway while I rode in the box. I'd say it would be ok for across town or a slow country road but it's not freeway worthy. Maybe the inside of the box could be sound dampened with foam upholstered paneling but it is hard to say and I'm not sure I want to make the investment to find out. Back to drawing board. Seating 3 in the cab opens up some options for the layout in the box.

 

[simple]

After a ton of reading, I think I'm going to stick with the stock 225/70/19.5 tire size. I really like the super singles but it doesn't appear that there are 6.17 ring and pinions for my rear axle to compensate for the increase in tire diameter. The gear ratios in the manual transmission match really well with the stock configuration. It might be different with an automatic.

 

[DirtWhiskey]

After a ton of reading, I think I'm going to stick with the stock 225/70/19.5 tire size. I really like the super singles but it doesn't appear that there are 6.17 ring and pinions for my rear axle to compensate for the increase in tire diameter. The gear ratios in the manual transmission match really well with the stock configuration. It might be different with an automatic.

Great truck, I'll be following this one. You have an epic suspension and axle setup. Dana 60 true "Super 60" wide track front with the S110 rear. Your turning radius is stellar for a truck of that size. I have a 2001 Super Duty crew fire truck I swapped over all the suspension and axles to from a 2006 donor (rebuilt everything) just to get your coil spring and wide track front. I went 5.38 and MPT81s and I turn 2300 at 60 mph with a 7.3 Powerstroke and 4r100. Just an FYI. Went Yukon for the rears and Dana Spicer for the front gears. Rear is a True Trac LSD and I put a Yukon Zip air locker in front. Not sure if anybody made a 6.17 but I'm also pretty sure finding lockers/mods for it would be hard. 5.38 is a lot of gear. The way I understand it the V10 rev/torque profile isn't too far off the 7.3.

 

[simple]

Thanks for the info on your setup. I think that would work for me as well. I am throttling back a little on how much I'm going to invest in this truck over building out the basics. The biggest restrictor is that we are going to try to sit 3 in the cab with manual trans and I think it will only work for a few years until our daughter outgrows the middle seat.

Now you have me calling about gears. LOL
I called Randy's ring and pinion and they told me they don't make a Yukon higher than 4:88 for a Dana S110.
East coast gear supply says Dana makes an aftermarket 5:38 and 6:14 for the S110 and only the 5:38 for the super 60.
I found the 6:17 gears on the DBL site. Made by them with limited applications.

Gears - DBL Design

At DBL Design, we know gear conversion is crucial for heavy-duty truck work. Some might say it's unnecessary, but we know better. Here's the lowdown:

www.dbldesign.com

I can't weigh in yet with much detail on the V-10. Haven't had time to go through it, check spark plugs etc. It's also 16yrs old with 130k, miles on it and I don't know the service history. I've had a 7.3 diesel in a 2001 e350 but the gross vehicle weight was a lot less and it was auto so hard to compare.

 

[danneskjold]

Thanks for the info on your setup. I think that would work for me as well. I am throttling back a little on how much I'm going to invest in this truck over building out the basics. The biggest restrictor is that we are going to try to sit 3 in the cab with manual trans and I think it will only work for a few years until our daughter outgrows the middle seat. Ultimately I'd like to go with a 3500 extended cab, single rear wheel with a lighter weight composite box.

Now you have me calling about gears. LOL
I called Randy's ring and pinion and they told me they don't make a Yukon higher than 4:88 for a Dana S110.
East coast gear supply says Dana makes an aftermarket 5:38 and 6:14 for the S110 and only the 5:38 for the super 60.
I found the 6:17 gears on the DBL site. Made by them with limited applications.

Gears - DBL Design

At DBL Design, we know gear conversion is crucial for heavy-duty truck work. Some might say it's unnecessary, but we know better. Here's the lowdown:

www.dbldesign.com

I can't weigh in yet with much detail on the V-10. Haven't had time to go through it, check spark plugs etc. It's also 16yrs old with 130k, miles on it and I don't know the service history. I've had a 7.3 diesel in a 2001 e350 but the gross vehicle weight was a lot less and it was auto so hard to compare. I've had 5 different Cummins 5.9 diesels with campers and trailers of similar weight as the crummy. A couple were turned up a hair and I can confidently say they stomped the crap out of this V-10 in its current state.

My F450 ambulance is on 4:88s with MPT81s, and I sit at about 1900rpm going 60-65. I never felt any power loss switching to those, and have zero regrets. If my truck makes it back to Seattle (I live in Seattle but moving to Bend in a couple months and the truck is currently there) you’re welcome to test it out.

Nitro makes gears for these trucks, the owner has an F450 RV with an S110 rear. He says 5:38s is the correct size.

 

[simple]

My F450 ambulance is on 4:88s with MPT81s, and I sit at about 1900rpm going 60-65. I never felt any power loss switching to those, and have zero regrets. If my truck makes it back to Seattle (I live in Seattle but moving to Bend in a couple months and the truck is currently there) you’re welcome to test it out.

Nitro makes gears for these trucks, the owner has an F450 RV with an S110 rear. He says 5:38s is the correct size.

Great info. Thanks for the offer to check it out. What motor do you have?

 

[OverlandFT]

Thanks for the info on your setup. I think that would work for me as well. I am throttling back a little on how much I'm going to invest in this truck over building out the basics. The biggest restrictor is that we are going to try to sit 3 in the cab with manual trans and I think it will only work for a few years until our daughter outgrows the middle seat. Ultimately I'd like to go with a 3500 extended cab, single rear wheel with a lighter weight composite box.

Agreed, 3 people in the cab with a manual is a little tight. I found a center seat for mine and built brackets to move the center seat back a few inches. It's enough room for now. When my daughter rides in the back, we fold down the center seat to make an arm rest and the cab becomes much more comfortable.

 

[danneskjold]

Great info. Thanks for the offer to check it out. What motor do you have?

6.0