The Stovebolt Site Forums The Parking Lot Big Bolts GMC 450 curb weight needed..... now with pictures

It has a 5th wheel on a 137"WB and 302 engine. I want to make sure my trailer is not overloaded. Plus I will need to winch it on.

Thanks

I don't have the curb weight for the GMC but the '53 Chevy 1-1/2 ton with the 137in wheelbase has a curb weight of 4775 lbs. with a flatbed and 5010 lbs. with a steakbed. You'll need to estimate for the different bed and engine but if might give you a starting point.

Curb weight of a 137"in. wheelbase model 451-30 will be 5725 lb.'s hyd. brakes, 5825 lb.'s with air actuated brakes, Then add weight of fifth wheel, so it will probably weigh approx. 6000-6200 lb.'s.

Thanks to both of you for your help.

Spanky, I thought the truck was a 137", but maybe I'm wrong cause the model is a 452-30a, but it's also supposed to be a 1953. Does the a stand for anything? Air? So I'm unclear, it could be a 149" WB. The page where I got the info listed the 452-30 as a 1954 model. Another foot in WB shouldn't add too much weight I'm guessing.

Thanks again

A 452 list as being 40 lb.'s heavier than a 451. Not sure what that "A" stands for. There should be a "GMC Parts Identification" plate on the back of the glove box lid, with all the trucks specifications.

Thanks Spanky.

I think the truck should be a plain jane, basic model because it was built for the military. It is supposed to have a military tag on it.

It took all day and then some to get the truck home. The truck squashed my trailer, the tag on the dash said empty weight was 7725 lbs. It did fit on the trailer, but I had a trailer tire smoking from rubbing the fender due to the weight. That had me scratching my head since I was out in the middle of nowhere. I have lived my entire life in Oregon, but I have never been to Twickenham or even heard of it, but it is beautiful and very remote.

The only rust on it was under the floor mat. It will need some floor board repair on the drivers side. I'll look over the truck better in the daylight tomorrow. It was a USAF truck originally. Then spent time in rural fire dept duty for the Forest Service.

I was told it was the oldest truck still assigned to the Forest Service in Oregon.

I took pictures, I'll work at getting them online.

Sounds like an adventure. Looking forward to seeing the pictures.
Congrats on getting her home.

It certainly was an adventure. It's somewhat difficult to believe it actually happened. Pictures tho, are the proof. If your not from Oregon you may have trouble picturing 5 mile, 7% downgrades on the back roads. That's what keeps life interesting when you have a load like this.

The truck has a 5 spd. 1st is all the way to the right and down, second is all the way to the left and up. Weird shift pattern. Plus there is a dir under 5th on the pattern sticker. What I like most about the truck is it hasn't been messed with up with a torch and welding rod. There are a few holes that need to be filled where there were extra emergency lights added on the fender and cab top.

I'm not positively sure but yellow appears to be the 1st color it was painted. Being a USAF truck, and that flight line trucks were yellow....it could have been one. Then came a red, then the white.

http://s1201.photobucket.com/albums/bb357/farwestmilitary/1953%20GMC%2045230%20tractor/?start=all

Nice looking truck! Glad to hear you got home safe...

Mike B

Nice truck! The transmission shift pattern sounds like the Clark thats in my COE. It really takes some getting used to. The shift pattern looks like this:
2 5 R
I-I-I
3 4 1

It takes some un-learning to drive with that tranny. Mine is actually an overdrive, so the way to shift the two speed rear in the upper gears is 4l - 5l - 4h - 5h.
Good luck with your truck. Is sure is a cool one.
Scott

I thought 5th on mine was where 4 is on your truck, but I'm probably remembering it wrong, otherwise it is the same. This truck has no overdrive, so I'm wondering how I should shift the rear. Was their a different 2spd rear for the OD transmission?. Have to get running before I can shift it tho.

Can't find any pictures of another like it on the web. There must not have been many made. If someone has a picture, please post a link. There is a military contract # on the dash.

I saw that auction with the 450 series along with a government specced 424, but I decided it was just too far to haul to TX. I was tempted though because there are some good paying flatbed loads from Texas to the Pacific Northwest. But I would have probably had to hire a wrecker to retrieve the 2 units and then to load them on a flat with no ramps. You have a Clark which was very popular in the 50's. What Scott is describing is what we called a working 5th. It is a transmission with close ratios between 4th and 5th. If you do not have the close ratio between 4th and 5th, it will shift 4th lo, 4th hi; 5th low, 5th hi. There should be a tag in the glove box and a tag on the transmission that will give you a model no. It could be a 205V or 207V which are direct or a 207VO which is an OD.

You probably would have had to do just that and to hire a wrecker would have been costly because it would have had an hour drive to get there. The closest town is very small and 25 miles away. The next town is another 50 miles away it's bigger.

The trans is a direct going by the shift pattern label, which has a dir under the 5. I'll look in the glove box tomorrow.

I bought the most original 56 Ford I have ever seen in Bend, OR a few years ago. I am familiar with the high desert of OR. I am sure recovery and storage of the 2 vehicles would have been more than the cost of the vehicles in the first place.

You're right it would have been alot more than the original cost and the bad thing is it's extremely hard if not impossible to predict costs as there are always complications. Like this original thread title. I was looking for the weight to determine if I could haul it with the trailer I had. You never know what you're in for until you get there.

The glove box plate says the transmission is a clark 205v. 2spd rear ratio's are 6.5/9.04.

Top Speed? 45mph?

The 205V is a Direct. The last year of the 302 was 1959 when it was rated at 160HP @ 3800 RPM so you don't have to worry about over revving it. The 6.50/9.04 was the slower of the 2 ratios offered but if you put 10x20 or 11x22.5 tires on it, it will run 60. The 424 they sold would have had a 302 in it also that was rated at 3800.

The tires on it are 9:00x20 and are almost new. I won't replace them. That would be a big expense. I will have to live with a slower top speed.

Even with nines, it will run faster than 45.

crenweige, What ratios were in the faster ratio 2spd rear?

Thanks

5.57/7.75 and 5.63/7.81

K9, I hauled pretty much the same truck from hershey pa to southeastern ohio. Mine was minus cab and transmission but was still very heavy. Made me wish I had a tri-axle trailer and a manual transmission!! Pa turnpike seemed to go on forever. Good looking truck you got there!

The truck dwarfs the trailer besides squashing it. I pulled it all with a 95 dodge with a cummins 12v. The truck was in such a remote location that I could not get any info off it before I arrived, so I was committed to haul it with what I had. I could not find any info or even pictures on a like truck off the web either. One guy that tried to help said his factory literature indicated a weight that was over 1500 lbs less than the plate states on my truck. I'd like to know why my truck is so different. Is your truck a tractor? Do you have any pictures? Thanks for the compliment.

My 450 COE started life as a road tractor as well. They appear to be set up a lot alike. Your 205v should have the following ratios:
1- 7.58:1, 2- 4.38:1, 3- 2.40:1, 4- 1.48:1, 5- direct. My 207vo has a .86 OD in fifth. Your rear with the 6.50-9.04 ratios should be an Eaton 16600 electric shifted two speed, same as mine. The 5.57-7.75 would likely have been in a diesel truck.
I'm running 8.25-20 tires. I have seen 60 on the speedometer. The engine was turning 3200+ rpm. If you're unfamiliar with these old trucks,3000 sounds like the lid is about to come off with the fan noise, etc. I can't imagine 3800.
Give me a shout when/ if you need any help finding parts. I wrote down all the part numbers that I've used and I might be able to save you some steps on chasis/brake items.

http://rides.webshots.com/photo/2094988510106941429dMCLOf

By the way I added a picture Spanky sent me of my truck, "back in the day", in it's former life as a road tractor.
Scott

K9, I pulled mine with a 91 Dodge 3/4 Cummins/auto, pulled it fine but it was the heaviest thing I have pulled to date. Its definitely heavier than the 89 dodge dually cummins I pulled a while back, and that was using a much heavier trailer I borrowed. I estimated that load at 8500lbs, 3000 for the trailer and 5500 for the truck. My 52 has the 3-71 and the two speed with 5.57 high range. It was a number 4 wheelbase but was shortened to about 142" wheelbase and used as a yard spotter.

Thanks Scott for the parts help offer. The rear is electrically shifted and I remember seeing Eaton, possibly in the glove box. It would be nice to cruise at 60 but I don't care for the noise or the fuel consumption when the engine gets too busy. Maybe I should think about a brownie aux transmission. The plate on the glove box door has a place for an auxiliary transmission, but it was blank. I wonder if it would have come with one, what model it would have been.

Your truck looks nice and you put it to good use. I would like to use my truck at least occasionally, possibly to bring something else home. I need to get it running 1st, then search for a trailer.

Peyton, I was wondering how my tranny temp was doing because the 1st 15 miles were almost all uphill on a slow curvy road that was barely wide enough for 2 pickups. I don't have a working temp gauge so I will never know. That 450 was certainly the heaviest load that trailer ever hauled.

K9, my GMC Maintence Manual lists the original auxiliary transmission as a Spicer model 5531-b. This is a three speed with a 2.36:1 under drive, direct, and .85:1 overdrive. Though, I believe a lot of junk yard scavenging went on in the past and a lot of trucks ended up with something other than what they would have had from the factory.
If you don't have a Maintance Manual, that would be a good thing to pick up. Mine has a green cover and is a number x-5209, it is specifically for models 450-470. And it is for a '52 year model with a revision date of 10-1952. I would imagine your 53 would be very similar. I also have a Master Parts Book, number x-152002. This shows you all the parts, and their number. Invaluable when going to the parts house, a lot of the numbers will cross over. These are a little more difficult to run across. Hope this helps.
You've never said if your truck had hydraulic, air over hydraulic or full air brakes. I was just curious because your truck is a road tractor. Mine is straight hydraulic.
Scott

I saw a compressor on it in the auction brochure. It must be air over hydraulic because the dive axle has hydraulic brakes. 60 mph with 9.00x20 tires will be 3400 rpm. These things were built to turn 3400 rpm all day long. 45 mph is only 2600 rpm. It is going to use a lot of gas whatever you do to it. At 60 mph the wind noise will probably drown out the fan and rocker noise any way. You need to remember this is a 60 year old truck.

It has air over hydraulic brakes. It actually has no brakes at the moment. On the glove box door the plate states AIR on the brake line. I was curious if full air was an option with this size truck.
The truck has an alternator on it now. Was it originally 6 volt and converted to 12v or was it 12v from the factory?
At 45mph fuel consumption should be much more reasonable than 60mph.

Full air was an option on the '47-'54 450, & 470 series GMC trucks. I have a 1952 GMC 470 series COE, with full air brakes.

Fuel consumption is a relative term. I get about 6-7 mpg and I average about 1/4 of the time loaded, 3/4 of the time tooling around, usually around 50 mph tops. It doesnt take long to see why the trucks had a large saddle tank on them.
The truck would have come from the factory as 6v positive ground. Mine had also been converted to 12v negative ground. Not absolutely original, but very handy in today's world. I have an electric brake control in mine as a necessity.
Scott

Air over hydraulic must have been considered air brakes. There is an air brake controller for trailers with air brakes, but I'n not sure how it's used or how it actually works. Obviously I've never used one.

My truck has 2 saddle tanks on it. Makes me think it can get thirsty. Scott, is that 6 to 7 mpg on the highway or an all around average?

It doesn't appear that any thought was given to the gauges when the conversion to 12v was done, but I'll look some more. There were 2 jars of tail lamps in the glovebox. It also has a knife type switch to cut off the battery from the starter. They moved the battery from it's original location because the mounting brace cracked and broke. I need to delve into the electrics some more.

Most of my driving is short trips. I haven't really put the truck on the highway and aired it out, so to speak. That 6-7 mpg is an all around average. Here is a good thread where someone has a much bigger frame of reference. He drove a 450 series gmc practically across country. The summary is on the 4th page, but it's all a good read.
Scott

https://www.stovebolt.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=743304&page=1

Air over is not straight air. It is merely a booster similar to vacuum boosted brakes. The foot pedal may not be tied into the trailer brake circuit. Most air over systems had a completely separate braking system on the tractor and the trailer. A trolly valve on the steering column controls the air to the trailer. If it is two separate systems, extreme caution should be used when pulling a trailer on slick roads. It was common to see this model trucks with a back corner bashed in from a jack knife. With full air, apportioning valves and ABS, the work jack knife has almost been removed from our vocabulary. While pulling a trailer, especially one that caught a lot of wind, this truck would have been lucky to 4 miles to the gallon.

If there was a full air option as it was stated in 1 of the preceding posts, I'm wondering how full air or straight air would be labeled on the glove box plate. My truck is listed as AIR on the line opposite brakes, but it is only air over.

k9, do you have a standard brake pedal or an air brake Treadle Pedal (looks like a gas pedal)?

My 1956 Chevy LCF has Air Over with a Treadle Pedal. It has two Master Cylinders that are actuated via an air chamber (one serves the front and the other the rear axle). I also have a Trolly valve for the trailer. I've never seen another set up like mine. The set up I have seems like a dangerous system...if I loose air I'm done. If you have the type with a air booster and you loose air you can still stand on the brake pedal to stop the truck because the pedal is connected to the Master Cylinder.

Mike B

I went out looked at my glove box tag. It says "AIR" next to service brakes. My truck is full air brakes.

Mike B, It's just a regular brake pedal. It does have 2 air tanks that are connected. Looks like only to increase air capacity. There is a air powered booster under there too.

Spanky, That's the way the tag reads on mine too. The a in 45230a probably stands for air also.

There is a military contract number on the dash plate. Anybody know where that number can be researched? It would be very interesting to know that history. It does give the build day or the delivery day(I'd have to check that again) for the truck which is cool.