The Stovebolt Site Forums The Parking Lot Big Bolts Information for a GMC 450

Hey guys, new member here.

I have been reading some posts here, and have tried to find the information that I want to know on the web, but information on this particular model is extremely hard to find, let alone just a diesel 450. I have seen some very helpful people on here, and I am hoping that somebody can fill in some blanks for me.
My father in law and I have recently purchased a 1953 GMC DW455-37 truck. It will be an on going restoration and trailer puller, as well as taking it to car shows.
It currently runs and drives, and we have put a few miles on it now.
We know the owner of the truck that owned it from 1960 until we bought it, so we have quite a lot of information on the truck already.
We were told that before the truck came to Canada in 1960, one of the rear differentials failed, so the frame was shortened, and a Mack single axle was installed. I know from the service manual and owners manuals that I have purchased, that the truck originally had tandem driven axles (no tag). By the glove box ID tag, the truck should have Eaton 22M differentials installed. Does anybody know if these differentials were used on other trucks? I would like to put the truck back to as close to original as I can, but I cant find any more information than what is in the service manual. Ideally, I'd love to find a parts frame with differentials that I could swap my cab and drive line into, but I don't know if I will get that lucky.
In the owners manual (and there is still parts of the system left on the truck), it talks about a cold weather starting air intake heater that was installed on the 3-71s. The system used a ignition coil and a kind of spark plug into the air box on the engine, and diesel was pumped via a hand pump on the dash into this heater, starting a fire in the engine to warm the air. I haven't been able to find much for information on these either, and I think having this system working would be really neat. I do have a system break down for it in my manual, but I haven't found any parts around for it.
I know that the d450 trucks were only made for two years. Does anybody know how many were produced? Id be especially interested to know how many were made of the DW455-37.
Ive been totally fascinated with this truck. How it looks, the GM diesel, the air over hydraulic brakes (bit of a challenge finding parts for the airpak, but we got it figured), and the 5+3 transmission.
I'm a Journeyman Motorcycle mechanic, and I also have done a lot of automotive repair work, but this big old truck is just something else.

Welcome,

As far as I know the GMC 450 with a 3-71 diesel was made in 52 with some sold in/as 53. I don't recall production numbers if they exist.

The air box heater you're thinking of was used on other inline 71 series in various applications, parts made for or by Detroit/GM Diesel. If hunting parts my first call would be to Leid Diesel Service in PA, 717-776-7725 Or In Michigan at 616-754-5871. They also have a location in Wisconsin, ask the others for a phone number. A good resource for all your Detroit 2 cycle needs.

The more practical solution is a plug in block heater, much less trouble and expense, and readily available new.

Grigg

Hy 76Buffalo, welcome, as Grigg says you have a very rare truck there. You are being "moderated" at the moment, which I think means that you cannot make or receive private messages, please make some more posts as I would like to send you a private message. I believe after four or five posts you will be able to receive private messages, good luck with your truck.

Thanks for the information, I will try giving them a call. My truck does have recirculating block heater on it already, but that factory air heater is a quite a conversation piece. Its so much different than modern glow plugs or grid heaters, and very few people have heard of a system like it. I will try to get a few more comments on here so that I'm not being moderated anymore.
Were the Gas powered 450 Tandems more common? I would assume that they would have the same transmissions/differential set up as the diesels.
We have the little jimmy running quite well now, and it sure is fun to drive with the twin sticks. I can wait to get a hitch setup on it and starting pulling with it.

When you find another rear axle for your truck, don't get too high of a ratio, if you have a choice, that engine will not haul that thing very fast, try to get a two speed, also.

Ed

I just looked in the GMC model 400-980 1947-53 parts book.
A DW455-37 truck had an Eaton SR 22M rear axle, no optional axles listed. Wheelbase of 197”.
Looks like it would also have a Spicer 5531B auxiliary transmission behind a Clark 204 VO

I presume tandem axles could be added aftermarket when the truck was new, or perhaps special ordered?
Seems to me if you needed tandem axle you’d be a lot better off with more engine than the little old 3-71.

The truck you have is very rare. However, it is not practical to use. The 371 makes a lot of noise, but very little power. It has about 25% less hp than a good running 302 gas engine. The 22M was the smallest of the twin screws with the interaxle drive shaft over the top. That whole idea didn't last very long because they were aimed for vocational use and were not strong enough to handle it. The heater may be a South Wind heater. You might consider leaving the rare truck in its original state and finding a 450 gas burner to set on a later model chassis.

Shes definitely no power house, but that's part of my attraction to the truck. I dont suppose Ill ever tow too heavy with it, maybe 15000lbs max once just to say I did. The weak rear ends is the story that I was told about this truck as well. I was told that when it was in the states hauling lumber in the 50's, one of the rear ends failed. They found this Mack single axle at a scrap yard and shortened the frame and welded it in. Unfortunately, the Mack rear end has a 6.14:1 ratio, when the factory rear ends should have been 6.7:1. It also has too large of rear tires right now (9:00-20, when stock is 8:25-20). With this set up it will do 100km/h, but it doesnt have much for towing power at all. I dont intended on chopping the truck up, just trying to put it back as close to factory as possible, especially because of how rare it is. If i cant find the correct rear ends for it, then it will likely stay with the Mack axle. The truck does have the Clark 204VO and the Spicer auxiliary transmission, Having that many gears sure helps get the truck up to speed. In my service manual, they refer to the differentials as Eaton 22MF and Eaton 22MR, or just Eaton 22M when talking about them as a pair. So these differentials were likely only used on the 450 series trucks then? That makes my search much harder.

Welcome to the site and to being a big bolt owner. That is a cool truck and admire your plan. A few of us own a 450 with air brakes and have had some fun getting it running and driving. I hope you can find those axles. Would love to see some pictures of the truck.
Good luck!

Hy 76Buffalo, please make some more posts, I would like contact you through a private message, thank you.

Hey Im sorry its been a long time since I posted! Ive had an interesting summer with the truck. I pulled it out of storage and drove it for a couple of days, and decided that the auxiliary transmission seemed noisy. I pulled the transmission and found that the bearings were all in a sad state, but the gears, shafts and shift forks all looked in good condition. I rebuilt the transmission with the proper bearings and preload, and it is much quieter now. I also built a wood flat deck for the truck, so I can start hauling some things around with it now. However, the truck is parked again for the moment, as I discovered that the engine mounts are done. I have searched the internet pretty heavily, and cannot find replacement mounts for the truck. This little Detroit makes things difficult when it comes to finding parts. Is there a company that can repair my old mounts? The metal parts of the mounts are good, but the rubber has torn. Let me know if this link works for the pictures. If it does I can ad a whole lot more pictures.

https://share.icloud.com/photos/0gstFny-TZLXr0u3jxBFwdvQQ

The link is good, the truck looks very fine.

I don't know much about Detroit motors except I would have thought that any part you needed would be available. I guess the mounts must be truck parts. Maybe some industrial equipment would use the same mounts.

Maybe some pictures of the mounts would help, they might be the same or similar to something else.

Hy 76Buffalo, welcome back, you have a private message

When it comes to strictly engine parts, my local Detroit dealer doesn't have any issue getting a hold of them. Its the parts of the truck that are special to the Detroit (or General Motors Diesel, I suppose) powered 450s that are near impossible to find. The engine mounts appear to be a GM part to adapt the engine to the chassis. For now I have sourced some vibration isolator mounts rated for 720 lbs max per mount from Acklands. Ill have to modify them a little bit, but for now its my best option I think.

Here is a link with a bunch more pictures, dont mind the random pictures of close ups of components.

https://share.icloud.com/photos/0dOK-m0zNzRKc3AXXrmcX1JlA

Here is a couple of pictures of the rear mounts

https://share.icloud.com/photos/0Fenr37_1bI6hP6UKjm8ZF-1A

Steele Rubber Products does revulcanizing of motor mounts. You have to send in all the pieces of yours and they will mold in new rubber.

What a cool old truck. Do you know it's history? Was it originally setup as a tractor with a fifth wheel? Is that a 4-71 ? 3-71? Mack rear end! I wonder what the ratio is. The only other similar diesel I remember belonged to a friend. It was a 630 with a sleeper, had a 4-71 and a 5x3 trans setup like that. He hauled furniture all over the country till he got married. Were it mine I'd hunt up one of those low air warning cylinders with the stop sign that flops down in front of your face when the air is low. As noisy as those things are you'd never hear the low air buzzer much less see the warning light tucked way down under the dash.

I actually have already tried contacting Steele, and they unfortunately cannot do my mounts because they do not have the necessary molds. The truck came to Canada near 1960. I know the third owner of the truck from 1960-2007 (where it was setup as a single axle tractor towing a low boy for about ten years, then it turned into a grain truck when he purchased a Dodge 1000 tractor with a 250 cummins), then it was sold at auction, and a couple years later was bought back by the long term owners nephew. The nephew passed away, and his assets went to auction, where I bought it. My father in law drove the truck in the 70s on the farm where he worked as the hired hand. Heres where it gets foggy, and dont have any solid proof. Before 1960, it was in the states, and belonged to the long term owners uncle (the second owner). He used the truck for hauling lumber from his mill in Washington. He bought the truck nearly new. I say nearly, because the first owner bought it, then had to bring the truck back to the dealer because he couldnt make the payments. It was during this time that one of the rear ends failed, and the truck was back halfed with the mack rear end. I have also found out, that it was in those first ten years some time that the auxiliary trans was changed from the Spicer 5531B to a Spicer 6031. The truck has a 3-71 General Motors Diesel. The rear end ratio looks to be 6.17 by the stamping on diff housing, but i have not pulled it apart to verify that. the truck will do 100km/h at 2000 rpm.

I searched "repair broken truck motor mounts" and this came up:



along with several others.

There appears to be some good information there, more in the comments.

A mold could be made of sheet plastic or tin, whatever worked and could be taped in place. Excess could be cut or sanded away.

I don't know this guy and I have never tried this method but my experience tells me it should work if you can't find another solution.
Here's hoping you get a good repair one way or the other.

Around here, snow plow blades come in 1" x 4" by length neoprene(among with steel) which work well to make mounts with. Machines well, get it cold.

Ed

76 -- I got some vibration isolaters from McMaster Carr to mount my brownie. I've though about using them as cab mounts too. They come in various ratings. They might be thicker though and you might have to modify a bracket or two.

I thought the 450 probably had once been a tandem axle, as single axle trucks usually had 2-speed axles not brownies. Hopefully that's a 6031A. Much friendlier on the road than the B model that had a deep under. The remaining two ratios of the B split the main box into effectively a 10-speed, not nearly enough gears for a little 71-series. With the A model you can split the main box three ways which gives you about 250 RPM between gears -- 24% under, direct, and 17% over as I recall.

It still amazes me that these old trucks hauled such loads with such little power. But then I remember when I started out driving on a B-model Mack over the Cascade mtns. with a 170hp diesel and a Mack Duplex 9-speed grossing 60,000. The line of cars behind me on the 10-mile Vantage grade stretched all the way back to the river. It took about 45 minutes. The last tanker I drove grossed 105,500 and would pull that grade at 30 MPH. It had a 600hp Cummins and 13 speeds and didn't need all of them.