The Stovebolt Site Forums The Parking Lot Big Bolts 50-51 1 1/2 or 2 Ton Drive Train Questions.

I'm bidding on a 1951 1.5 ton on EBay (hoping to change my signature block) Before that I was trying for a 1950 2 Ton. I started doing my research after deciding what I wanted to get, naturally.

I know a lot about cars, but not so much about trucks. So here goes:

1. The truck I'm bidding on is advertised as having a 3-speed in it. Naturally, I would like to put a 5-speed in it with fifth being an overdrive. Conveniently, the transmission to engine mounting is supposed to be common to the Chevy Small Block. I was on the trail of a suitable transmission but it turned out the be an International Harvester product. Not sure how easy it would be to find an adapter. Any suggestions?

2. The 2 ton that I didn't win had an Eaton 2-Speed rear axle (one of the main reasons why I wanted it) After reading posts here for a while I understand that there was also an electric two speed. I drove a C-65 Chevy with a vacuum operated 2-speed rear axle for a while and loved it. I drove an electrically operated 2-speed very briefly and hated it. Needless to say, I would like to have a vacuum operated 2-speed in whatever I end up with. How rare are those Eatons? Is there a modern replacement that doesn't require much modification?

3. I'm assuming that using a later model rear end would allow later model brakes. If I end up using an early rear axle, though, how hard would it be to put late model brakes on it? I got the impression, from I know not where, that if I changed the brake backing plates I could put whatever brakes on it I wanted to as long as the axle length didn't push the brake drum out past the brake shoes. Any thoughts?

I guess this is enough for now. Tnx in advance.

I sort of doubt that a 1.5 ton would have a 3 speed transmission. The standard would have been a 4 speed. Perhaps they meant a 3 speed with the granny low gear, a lot of folks get this confused. As far as I know the Eaton 2 speed rears (17.5+) were all electric operation and the Chevrolet rears (15K) were all vacuum operated.

I cannot help you on the brake question but am sure others will know.

You're mistaken about the Eatons. Check this page: http://chevy.tocmp.com/booklets/48eaton06.htm

Good point about the granny low. I find it difficult to believe that a three speed would be very useful in a truck that size with a 216 in it.

The axle in the truck you are looking at is more than likely a vacuum shift if it is two speed, it was an option for 1.5 ton. The gear ratios will be slow and slower. Not sure what your plans are for the truck, but if you want to go fast you don't want a two speed, or even an old axle. Something newer that was available with faster ratios would be a good idea.

An adapter is probably hard to find or non existent to match an IH trans to a Chevy. Are you sure the trans you were considering is an overdrive? With some careful measuring and machine work it may fit if you try hard enough.

Think about what you want the truck to do, then let us know. Your answer will help us advise you as to weather axle and brake swaps are worth the effort or not. While you figure what you want to do with the truck this site may help http://www.drivetraindirect.com/t_gear_calculator.htm

Grigg

Believe it or not, I plan to use the truck for very light duty hauling (2-3 sheets of plywood) and cruising, as well as some experimentation with lubrication systems. I might occasionally use it to pull a trailered vehicle, but probably nothing really heavy.

I'm not going to restore it, but I don't want to make it un-restorable. I would definitely like to put a newer rear end in it, but haven't really found the information I need to point me towards one.

Brakes would be very important. High power is probably not essential. Driveability is more important.

How fast do you want to drive both empty, and with a trailer?
How heavy a trailer with load would you pull, and how far?
What engine ideas do you have? 6 cylinder, V8, diesel, or...?

Do you really need a 1-1/2 or 2-ton truck for this purpose? A 1-ton or lighter truck is going to be much more drivable and much easier to find parts for.

I would be happy with 60 on the flat and 45 on hills towing 4 tons or less for distances less than 2000 miles.

I probably wouldn't haul anything heavier than an engine-transmission combo on the flatbed although it may have a standard load of a couple hundred pounds of tools.

I don't have a firm idea on engines yet. I love Diesels, but don't like to work on them, so that path is out. The only four engines I'm seriously considering are 250 I6, 292 I6, 262 V-6 or an SBC. I guess the final decision will be based on a combination of cost and availability, both of the engine and parts for it.

I am currently in much the same situation. I have a 51, 1.5 ton flat bed with hoist that I am restoring. After much consideration, I am installing a new 261 motor with the existing drive train. I am lucky in that the truck has an original option of the 5.43 rear end. The truck could reach 60 miles/hr with that gear ratio, with the orignal 216 straining a bit. I am ok with the speed of 60 miles/hr but the power of the 216 and low pressure oiler was going to be a problem. Everyone, and I mean everyone has stated that a newer high pressure engine must be installed if you want to really use the vehicle. You are risking the 216 engine at any highway speeds above 55 miles/hr and that is with the 5.43 gear. If the truck has the 6.17, then you are in more trouble. I will live with the 5.43, and 60 miles/hr with the newer 261 engine. At least I know I can drive it on the highway but maintain much of the original look.

Good Luck

51flatbedchev

Did you win the auction on the 1-1/2 ton? Which model is it? 4100, 4400?

I own a '51 4400. Mine has a later 235 under the hood. I'd tell you how it drives but the truth is it was towed here and I've never started it.

Your objectives can be accomplished with this truck but you'll be making a lot of changes to make it keep up at highway speeds on a long trip.

I did win the auction. $858. I'm not sure whether it is a 4100 or a 4400 and it is about 400 miles away. I bought a 73 C-30 so I can go get it. (Actually, that one is for my wife so she won't gripe at me about mine.)

The VIN is 9JKD14760 and I can't find a VIN decoder right now that will tell me much about it except that it is supposed to be a motor home with a GVW of 4000 to 5100 pounds. (?)

I realized form the start that it would require major mods to become a highway cruiser, but I have time on my hands.

Anyone out there done a Dana 70 or 80 swap into a '51 1.5 ton?

The VIN 9JKD14760 is almost correct for a 51 4400 1 1/2 ton 161 wheel base. The J is the correct year code for 1951 in light and medium trucks but it is a U for heavy duty trucks. The K is correct for 4400 for every year 48-51. The 9 is correct for the Norwood OH assembly plant. The D is the month code for April. I think the U stamped on the plate may look like a J. So I guess April 1951 4400 Norwood. Try TOCMP for more info.

I have done a Dana 70HD swap on my 48 6400.
All details of that swap apply to your 51 4400.
Pictures and info can be found on the link bellow.
Grigg

Thanks a lot, both of you. The owner says she doesn't know where the VIN is on the truck but the title has 9JKD14760 on it. I hope its the right title for that truck. Wait a minute. I remember now that some states used the engine number as the VIN, and the engine is not original. Could that be it? The engine in it looks like a late model 235 to me. Anyway, I hope it isn't going to cause any trouble registering it. Is this one of the ones where there is a VIN on one of the frame rails about two feet behind the bumper?

Grigg, I'll take a look at those pictures. I'm amazed that the Dana 70 looks so good for a swap, price, ratio availability, everything. Please tell me that it isn't too good to be true. I'm also interested in that 4-53T. How hard was it to find that engine?

I don't know about other Dana 70 axles, but the 70HD I used from a late 80's Chevy P30 chassis is a great swap.
The axle tube is the same diameter, so you can use the old u-bolt saddles.
The spring perch pads need to be each moved out exactly an inch. Not difficult with a grinder and a welder. I recommend tacking them after loosely installing the axle in the complete truck and setting pinion angle, then take it out for final welding.
The width works with no tire fitment problems.
Ratios are available from 3.54 to 7.?? or perhaps even slower.
The downside may be that a Detroit Locker or an ARB are your only choices for a locker. The Detroit is good, but not for everyone and every situation. The ARB is great for everything except price.
The wheel bolt pattern is exactly the same, so the old wheels work.
A big downside to the axle I used is the disk brakes. I love them, and am glad I have them, but they require that you have disk in the front, and that is a task not so easily tackled.

As for the 4-53T, they are not at all hard to find. If you want one in great shape it will take some looking or rebuilding. To find a good one at a great price takes lots and lots of searching. It is not a simple swap. I will have hundreds if not thousands of hours in labor in mine before I am done. Not to mention the many thousands of dollars for all the parts and pieces it takes to do a professional job.

Grigg

I noticed that your shop seems to have a lot of tools in it that most don't. Great pictures of Bubba by the way.We have nine 'moldy meatloafs' of our own. They're good for providing constructive criticism but, without thumbs, they can't pass tools very well.

I have to ask. Did you do the welding on that narrowed front axle? If so, Im' not surprised you took so many pictures of it. Wouldn't it have been easier to do a little grinding and weld on a piece of plate instead of widening the spring perches with welds? Was there any problem with normalizing after those welds?

No, I did not do the welding on my front axle. I did not trust my welding skills at the time, so I had a blacksmith friend do the actual welding, I did the rest. If I had to do it again I would have no problem welding it myself now.
As for widening the spring perches with the stick welder. It was easier and faster to weld the little bit they needed rather than weld a plate to it. There was not enough missing to need anything more than a few passes with the welder.

To start the process of welding we first heated both halves of the axle with the torch till they sizzled when a drop of watter was dropped on them, not sure of the actual or ideal temperature. Then we started welding, and checking to be sure that everything stayed warm, and if not rewarming with the torch.

At the completion of the welding the axle was wrapped in some sort of white fluffy ceramic insulation, kinda like a blanket for really hot stuff. It was allowed to cool very slowly back to room temperature. By doing it this way it is supposed to reduce the formation of hard brittle spots at the junction of the weld and base metal. I think it has something to do with hydrogen, apparently it causes the brittleness, and when the parts are hot before and during welding the hydrogen has less of a chance of getting in the weld?

I used a stick welder and 7018 rod. I would not use a MIG welder as they tend to make very hard brittle welds. I see no problems with TIG welding an axle, it may be even better than stick welding in this case.

Grigg

Frank50, you're right on the money. The previous owner re-checked the title and it is 9UKD. I guess that means no hassle with the DMV, and I can change my signature block.

Just bought a 1951 4400 series with 74,000 original (Actual) miles from a local (50 Mi.) school district. It came with over 50 years of service records and the numbers match. I will try to post a pic when i figure out how, since there is no mention of uploading images here. I need to learn about the url thing

Elkaholic,
Try starting a fresh new post with your news and questions.
You will get more interest that way than by tacking it to the end of a nearly dead thread.

Grigg

Link to pics on another forum

Now let's see if this works! DARN it didn't!!!
But if you go to "classified" forums ...."automotive.....I bet you can find it!!

Another


This one will get you there