51 5 window dump truck
 

There's a 51(ish) 5 window 2 ton(I think) dump truck that's been sitting out in a field here forever. Thought it would be cool for a work truck with that dump bed. 2 speed rear end which I think are 6.13/8.something. has anybody ever taken one of these and put a more modern drivetrain in it and tires big enough to make use of the gears? I thing 42s would work. Can't find any pictures.

Re: 51 5 window dump truck
 

i think you would need better than a 42" diameter tire (thats about what a modern 11R22.5 is in diameter) to make a 6.13 rear gear palatable. the gear calc says 2000 rpm with a 42" diameter tire would be ~40 mph. so you would definitely want a 5th gear, an overdrive, to get you to even 50mph.

but even if you can find a 45" tire, its gonna ride like a buckboard empty with all those springs. maybe go drive a modern dump truck for a feeling of what you will be using as a work truck, then imagine it much much much rougher and harder to steer (no power steering in 51). I drove an empty grain truck about 4 miles home once, it felt a little like the steering wheel was connected to a marshmallow that was connected to an elf that shouted instructions to another elf that was connected to the steering box, then more marshmallows in the tire rods and so on.

given that its been sitting so long, maybe think about a modern drivetrain AND chassis swap, like an older one ton dually. it will likely have a similar load capacity as the older truck and will drive a whole lot better.

Re: 51 5 window dump truck
 

I was a heavy duty mech for highway trucks for awhile. driving an empty truck is called "bobtailing", nobody wants to do that as it is quite a rough trip, especially with springs and not air bags like most modern heavy trucks have.
if you wanna haul heavy stuff, like a regular dump truck, then you're gonna need a modern regular dump truck chassis under it with the powertrain to match. otherwise, if you like the look of a dump truck but rather like the ride of a regular truck then maybe convert it to modern 1 ton underpinnigs. yes, it won't have the look or function of a dump truck as far as weight hauling, but ask any modern dump truck driver if they like to drive their work truck after hours just for fun......nope would be the come back, pretty sure.
maybe think about a solid axle up front, if thats what you want, with power steering, then an airbag suspension out back with a modern axle ratio and a modern engine/trans combo (with overdrive, automatic etc). that would make it driveable for short trips etc. if you want the big truck look and feel then use a modern big truck underneath, but go for the air bags out back if possible. there are loits of 2 tone modrn trucks with decent ride capabilities and you likely see them driving down the highway. ait, tilt, cruise, locks, windows, power seats, etc etc. get one of those and stick the old body on top if thats what you wantm a work truck that drives ok and doesn't just rive you from chiropracter appt to chiropracter appt.lol.

Re: 51 5 window dump truck
 

lots of guys use the big trucks as donors for their cabs because the cabs are usually in pretty good shape since the big trucks don't see as much use as the smaller trucks. they then get the front sheet metal for the smaller truck and assemble the unit onto a smaller truck frame. just a thought.
if you want a big fendered unit thats great too, just find a modern truck with the capacity you want and put the old truck cab and front end onto that set up. you might look at auctions or insurance lots for a donor. a donor is a great way to go because it comes with just about everything you need to do the swap.
for more info on frame drawings etc look at the gmupfitters site as they have a lot of info there under body builder manuals, including frame drawings with dimensions. i would think a modern medium duty truck witha diesel engine and the trans type of your choice wouldn't be a far stretch to think your old cab and front end could be grafted onto it.

Re: 51 5 window dump truck
 

Sorry guys, should have clarified. The 2 speed rear would be the only stock part of the drivetrain. It would have 3 or 5 link suspension with bags, an NV4500 and an 8.1 LS if I can find one. Turbo 6.0 if not. Modern steering, modern brakes.

Re: 51 5 window dump truck
 

i have no idea why you would go that far on everything else and keep that original 2 spd rear, but the heart wants what it wants I guess. I have built a lot of things because I wanted em too. good luck to you! and show us the project thread when you get started.

Re: 51 5 window dump truck
 

try and get your hands on a factory assembly manual if you can. it will have drawings with dimensions for the frame, body etc plus how the factory put stuff together, where spot welds are on the body etc etc.

Re: 51 5 window dump truck
 

got any pics of your possible project?

Re: 51 5 window dump truck
 

I wanna see one of these trucks on 42s first. That's why I started the thread.

Re: 51 5 window dump truck
 

Oh you mean pics of the dump truck? Yeah. I've gotta go up there this week sometime. I'll post a pic. Hope my ļast post didn't sound rude.

Re: 51 5 window dump truck
 

A 7.50 20 tire is 35.6 inches in diameter or real close to it. In theory with that rear axle 44 inch tires would drop the rpm 552 at 50 mph from 2893 to 2341 with a 1 to 1 output ratio on the trans.

Still you would have to have very expensive custom wheels made to fit that axle and if you swap to something different on the front you are going to have two different lug patterns anyhow Plus the 2 speed adds 150 lbs to an already serously heavy rear axle. The axle ratios are 8.10 low and 6.13 high and unless you are planning on hauling full loads of gravel out of a pit the 8.10 isn't going to do you much good out side of giving you another set of gears to shift though.

Re: 51 5 window dump truck
 

Here's the truck in question if I looked it right.

Re: 51 5 window dump truck
 

I would say scoop it, and the little brothers too. you couls sell or trade the siblings to pay for parts you need.
not sure on the track width for those big fender trucks, you could check an assembly manual to get dimensions, but you could likely throw that cab and front end onto a newer frame for sure, witha diesel if desired, and keep the tires inside the fenders so it looks right.
here is a link to a site that may have the info you need. dunno for sure. it likely has cab dimensions though.
http://chevy.oldcarmanualproject.com...esto/index.htm

this should be a page with a dually that has the track width info
http://chevy.oldcarmanualproject.com...esto/53074.htm
this site has come in handy several times, possibly good to bookmark it for future reference.

Re: 51 5 window dump truck
 

Stomped through the snow drifts today and got a little closer picture. Behind is a 60s or 70s dodge half ton, and a 65ish chevy longbed stepside. Little farther away is a 52ish GMC 3 window long bed stepside 3/4 ton. I asked the old rancher what he'd take for the dump truck. He needed to ask someone else and call me. He said it hasn't moved in 40 years. I'd love to see what it would like lifted just a little with 35s and a flatbed. The wheel well opening is about 38".

Re: 51 5 window dump truck
 

Attachment 2260851
pretty sure these are big truck fenders and hood

Re: 51 5 window dump truck
 

Thanks Lee. Do you know anything about that truck?

Re: 51 5 window dump truck
 

Question about the tilt mechanism. I can see it's PTO. Are they a good setup? And is it something that can be adapted to an NV4500? I know they have a PTO output.

Re: 51 5 window dump truck
 

Hi Clint, I just googled for a picture
'advanced design' 'big truck' 4x4
or something like that and scrolled through the images looking for the bigger wheel arch.

There are some posts on this site that detail the difference between 1/2ton and 1.5+ ton fenders and hood. They are a longer, fenders are taller and hood flatter, bigger wheel openings but not a lot wider. Back in the day big truck tires were taller but not much wider.

Somewhere is a build thread that used big truck front clip for a late model 2wd frame swap as the big truck sheet metal was wide enough to cover the wider 2wd front track. That part worked out, but then they had a big task reducing the wheel openings to look good and that included shortening the fenders and hood and grafting in 1/2 ton wheel openings. Widening half ton fenders might have been easier.

I think you will find that big tire 4x4 look is not going to be easy to get unless the fenders sit high over the tires and stick out past the lip - big truck fenders or not.

If you want a 45 mph dump truck and that truck is an easy fixer go for it.
If you want a modern performance dump truck you are going to have to throw away most of the running gear and figure out how to make newer stuff fit and the reality in the shop is going to be harder than pictures on the Internet might lead you to think.

The question about the dump lift is not answerable, without some details about, what kind of dump setup it is , how well it is currently put together. If it is a factory dump and not hacked up after 40 odd years use that is probably a good sign. But a lot of these trucks were sold as cab and chassis or fixed deck so the dump lift could be anything stuck together with any skill level.

the truck in the pictures looks worth saving

Re: 51 5 window dump truck
 

if youu look up the thread by bbeep he uses some big trquck fenders on his trailblazer frame swapped AD suburban. he explains the differences in the fender height and length as well as the hood. I think he grafted 1/2 ton fenders together with the big truck fenders to get the wheel opening size he needed and also the height, since the big fendered hood is longer but not as tall due to taller fenders.
the pto is an unknown because the gears on the pto need to match te
he gears on the countershaft of the trans. the bolt pattern may be the same but you gotta know about the gears too. as Leegreen says, it is really hard to know if the hydraulic lift would be any good because of the points noted. most of thw time the farmer would do as much work himself as he could to save money, that means it could be done right or just done to the best of the farmers abilities, budget, time he had to do the job between farm chores and parts available. you really gotta see it up close and unload all the pivot points etc so you can see what you have.
if you like the truck, have the budget, know of an available donor truck with a good driveline or are not afraid to spend some momey on one, have the space to store parts after everything is taken apart, have the shop space required to do the work, and an understanding spouse (if applicable) then make the dude an offer and see where it goes. te
the frames are really quite straight on these trucks so you could use the existing cab, frame, body etc and install an updated rear axle, engine, transmission, power steering and brakes etc. it may cost a few bucks to do that, especially if you do it a part at a time vs buying a donor with as much stuff as you need already there for the picking. if you want a big truck that can haul, then look for a donor with the same kinda GVW so you can get the axle, brakes, trans and engine that is suited for that need.

Re: 51 5 window dump truck
 

the 4x4 pic posted actually shows the hood rise to allow for the taller fenders. compare a pic of each truck, small and large, and you can see the height difference at the front of the hood as well as a different line where the fenders and hood meet.
if you're looking to build a truck like the 4x4 then a frame swap might be the way to go. the wider fenders on the big fendered truck would cover the wider stance of the newer 4x4 better.

Re: 51 5 window dump truck
 

yeah bbeep's thread is the one I was remembering. Some pictures showing how 1/2 ton and big truck fenders and hood differ start around post 200

http://67-72chevytrucks.com/vboard/s...=348244&page=8

Re: 51 5 window dump truck
 

saddle gas tank means its a 47-48. nice find.

Re: 51 5 window dump truck
 

Posted on 47-59 Chevy truck forum 9-2012:
http://67-72chevytrucks.com/vboard/s...&postcount=213


Sold at auction 12-2012:
https://www.mecum.com/lots/KC1212-14...t-3600-pickup/


Looks like it was up for sale again in 2019. Lotsa details here, too.
https://www.artandspeed.com/vehicles...rolet-3600-4x4

And a video:
https://www.youtube.com/watch?v=72gCFtT-e78

Looks like the buyer left a clue:
"
richard cohane
1 year ago (edited)
I love this truck! Now it’s sittn in my garage. Thank you Art and Speed"

Hmm... Looks like the truck is entertaining a whole new crowd today.
https://www.facebook.com/photo/?fbid...a.440278893656

Re: 51 5 window dump truck
 

good sleuthing!

the larger wheels and tires in the 2019 ad don't suit the truck IMO

at the start of the build thread it does say 1.5 ton fenders
http://67-72chevytrucks.com/vboard/s...d.php?t=412326

Re: 51 5 window dump truck
 

yeah, I'm with LG on the wrong choice of wheels there on the big blue 4x truck. not a big fan of the old truck sitting on top of a chassis with wheels that are 1/2 or more sticking out past the fenders. the choice of wheel design is a personal choice too but I would prolly not pick those. thats just me though. it looks like a nice build but the wheel choice makes it look like a high school kid built it.
again, just my opinion that doesn't count because it's not my truck.