The Stovebolt Site Forums The Parking Lot Big Bolts 5.43 gears for a 2 Ton?

Browsing the forum Ive seen info pertaining to these rearend gears. Are there any good usable sets out there?? OR are they as rare as everyone claims they are? Im planning a SB/TB400 swap, and the big 6.17 ??gears will obviously equate into some RPM's at top speed. I figured if they were available, I would make the swap.
Perhaps a 700R4 O/D would help. I'll never have a load on, other than the BIGBOLT itself.
Thoughts??

What wheel bolt pattern do you have? if it is 5/10 on 7.25", then a D-70/80 with the same pattern is an option, however 22.5 wheels are getting hard to find. if the 5 or 6 on 8, or ?, look for modern axles w/ higher gears

Sorry, I should have provided more specific info,
I'm still learning the peculiarities of these monsters:

1946,2 Ton,10 hole,4.75" ID early type,7.25" bolt circle.
Leaving it to be a 20x6 rim size? For use with 900x20 tubed bias rubber?
Am I wrong in thinking that the ring and pinion can be swapped, retaining all of my existing external hardware?
I was thinking if someone had upgraded to a newer 1 ton set-up, they could shell the 5.43 cluster out, and I could use it as replacement...
Otherwise I can just build the small block to spin comfortably at 7,500 RPM, and let her sing.

I have a Dana 80 in mine with the same bolt pattern.I use P-30 motorhome 19.5 modern radial tires.Tires are a little smaller in diameter then the originals but they can handle 75MPH and can be replaced anywhere in the country.

Big block with a TH400 and a 33% overdrive behind that.

You could consider a 700R4 overdrive transmission to bring the RPMs down.

Yes, I think a 700R4 would be a good choice...

I forgot to mention mine has 4.56 gears.
My original rear end was a two speed with 6.17 and 8.17 ratios.
It was awesome and I wanted to keep it but I also wanted to travel at highway speeds.
That is why I put the P30 axle in mine.Massive disc brakes too.
With the discs in the back,P30 discs in front and the hydroboost master cylinder my truck will lock up all 6 tires instantly.
Master cylinder is mounted behind the cab and is actuated through a bellcrank from the pedal.
Better brakes than my modern Silverado diesel.

Awesome Shercoman...good info to keep in mind. A big truck to get shut down.

I searched for a 5.43 R&P for three years and finally gave up. It was an "option" that apparently no one was that interested in. Given that these trucks were built before there was an "Interstate Highway System"...probably understandable.

Mine? A Dana 80HD rear with lots of gear ratios and 19.5 tubeless radials plus spacer adapters for the front (the newer rims have a 1/4" bigger center hole).

Would have LOVED to have kept the original mongo rims & tires but...

Im in love with the 'mongo' rims...I gotta keep mine. I'll make way with the tall gears. OR-Perhaps I'll get lucky when I open mine up, and have a gift from the Chevy gods.

It is understandable pre-interstate...who would ever need more than 55mph? Ive restored some early Brit bikes with 3 and 4 speed gearboxes...45mph tops! which is still about 10 mph faster than they safely handled. Prior to tapered roller bearings, these headsets made for a nasty wobble at speed.

Back when I was still a licensed salvage dealer I sold several complete single axles to guys who cut the modern axle stubs out and had the axle stub from their old vehicles welded in. It takes a pretty large lathe to swing a banjo housing, but its not that difficult an operation. Popular ratios that Eaton makes are 4.56, 5.14, 583, 6.33 and and 6.17.

I've seen some trucks at shows with modern center housings and reuse old original spindles, hubs, and brakes.

In many cases that seems a step backwards to me. With the faster speed you may need/appreciate better brakes, or at least new enough brakes you can easily get parts for.
Better off swapping the whole axle complete, and the P30 axles share bolt pattern with many of these old trucks, a natural choice and good swap.

BTW --- Chevy very thoughtfully stamped the tooth count as well as the actual ratio onto the flat side of the ring gear if you want to absolutely certain of what you have.

Here is a pic of what mine looked like...

[img]https://farm9.staticflickr.com/8532/8619846637_ef94b12949.jpg[/img]REndNumber4 by tango88, on Flickr

Yes, I need to open mine up to see what Ive got.

Swapping the entire drive axle, may end up happening.
Modern brakes would be cool. So many options to decide.
Where does one stop? LOL Upgrade upgrade upgrade...then you
could have bought a used '09 Chevy for the same price. LOL
You just gotta love the old trucks though...

You can have your old wheels bored to the 5.25" center hole, or find 20" wheels from a truck later than about 1955 as they had jumped from the 4.75" up to 5.25" center hole by then.

Grigg

It depends on what you want to do with it.
If you intend to drive regularly in modern traffic you must have very good brakes.
Previously I had a '41 1/2 ton with completely restored brakes.I narrowly missed several accidents because people would quickly pull in front of me in traffic and then hit their brakes. I almost rear ended a Corvette when one did this to me. If I hadn't had a clear lane to my right to get in to I would have blasted him,even though I had good clear distance before he pulled in front of me.
Old style brakes don't stop fast enough in modern traffic.
At least put discs on the front.That is what I did with my 1/2 ton and it stopped really well. I drove that truck every day for years.

My original plan...which keeps changing as I learn, was to go disc conversion up front and keep the stock rear drive set up.
Thanks everyone for the input. Knowledge is power!!

Luke
I see you're a dirt biker.
Check out some of the other albums in my Photobucket for some past projects.

Very cool....Now I have to go dig up some of my projects and throw them in photobucket. LOL
Birds of a feather here, it seems.

Added some photos to the bucket...various Photobucket projects

That's cool!!!
Is it finished?

Not that one....feel free to browse the other buckets...:)

I'll second the need for better braking power. I'm going with big power disks all around. And newer gen tubeless radial tires as well. Like I said, I had hoped to keep the big ol' narrow 20 x 5's but they just present too many shortcomings if you plan on ever hitting an interstate. The old stuff was all fine for 45 mph but won't cut it at 65-70. Especially on a Big Bolt.

I have a canadian made 47 1.5 ton, and I wrecked another 47 1.5 ton. Maybe canadian ones were different? Both had the 5.47 rear. There was certainly nothing speedy about the roads here at that time. Maybe better luck searching north of the border?

Interesting information...I will keep my eyes peeled.

1.5 tons are usually single speed axles, and 2 ton is most often 2 speed in these years.

It is common to find faster ratio in the single speed than in the 2 speed, and the gears alone are not interchangeable, though the complete axle assembly would be.

Mine is a single speed rear end...
I have yet to ID the ratios.
When the snow and cold subside,
I plan on getting this thing into the garage
to check it out.

I'm very interested in what you used to convert your truck. My neighbor has an older GMC motor home he is dismantling for the engine and trans, so I may have access to the axles. He also has a P30 van of unknown vintage.

I have a '52 2 ton that I need a better highway ratio for and I want to go with either 19.5 or 22.5 Budd wheels. My goal is to haul a car on the bed and pull a trailer with another car on it. I had a 292 built for 350 lbs ft of torque for power...

I didn't read the whole thread, but I just put a beefed up 700R4 in mine. I'm running 2500 @ 65 (SBC) with the ol' 6.17's. I'm happy. I also want to update wheels and tires, but, in due time. You can also go with GMs beefier transmission.. 4L80E but it requires a computer to handle shifting. They have kits. I opted for the weaker transmission, and just had a really pro build on it. My truck is 6K empty, but like you I never carry a load. Seems to be fine and runs cool (tranny).

Good information- Thanks!!

Reading back through this thread I realized the importance of defining what your expectations are and how you plan on using your Big Bolt.

I absolutely agree that well maintained originals rims, tube tires and drum brakes are wholly adequate for the what the truck was intended to do. That was, haul stuff over rough roads at 45 mph. For in town use with occasional short highway runs, they will be fine.

I am rebuilding my 1.5 ton school bus into a long range traveler and need to be able to maintain 65 or so for extended periods. That's why I went with the Dana 80HD axle and it's gearing as well as the 19.5" '98 Chevy rims which will take new gen, readily available tubeless tires.

BTW...the engine is now a Cummins 4BT turbo diesel that runs best at only about 1700 to 1800 rpm. Between the lower rpm's and granny original gears, I had to make quite a few changes including an Allison six-speed double OD tranny.

All I'm saying here is...define what you want it to do, then build accordingly. Whether it is to be 100% original, a rat rod, a workhorse or a long haul rambler.

Well said Tango...these trucks have the adaptability to perform how ever the builder/restorer wants. (Money and time being the only factor as a limitation.) Some examples are so nice, they need to be 'restored' and restored to as close to 100% as possible. These are NOT daily drivers.
Some make work trucks, some modern haulers or hot rods, and the rough ones which are nearly gone---make good ratrods. LOL

Stovebolt forum is so cool, because it lends itself just as the trucks themselves do, to a wide array of information variables.

I wanna see the Cummins in that Bigbolt!!!

No real reason not to drive an original/restored truck as often as you want.
These trucks were new once and people drove them all the time anywhere they wanted to, and we can still do the same.
Upgrades and modifications may be nice but by no means are they necessary to drive and use these antique trucks.

I personally drove 1950's 2 tons with a load of 2,000 gallons of gasoline. We ran 60 or so on paved roads. Not that fast on gravel roads, but we did it 5 days a week and always at full throttle. I pulled 8,000 gallons of gasoline and a grain trailer with a 550 GMC. It would run 70 on level ground and a lot faster down hill. Upgrades that are available now weren't invented back then and we didn't need them. We had less wrecker calls back then when everything was mechanical than the new trucks that shut down when a sensor goes out. If you want upgrades, its your vehicle do do with it what you want, but we did just fine with what we had back then. I have had a commercial license for over 55 years and drove several years without a license.

I love the wisdom shared here: Even if we have drifted in and around the topic. LOL.
Keep the comments coming...

I'm very interested in what you used to convert your truck. My neighbor has an older GMC motor home he is dismantling for the engine and trans, so I may have access to the axles. He also has a P30 van of unknown vintage.

I have a '52 2 ton that I need a better highway ratio for and I want to go with either 19.5 or 22.5 Budd wheels. My goal is to haul a car on the bed and pull a trailer with another car on it. I had a 292 built for 350 lbs ft of torque for power... [/quote]

Bigdreamer-What would you like to know?

What is the rear axle from ?

The entire independent front suspension assembly and the rear axle are from the same P30 motorhome chassis.I would have to search my records to find the exact year but I think it was mid 70's.It has the same 10 on 7.25 rear and 5 on 7.25 bolt pattern as the original wheels had.
I think the rear axle is a dana 14 and it has large disc brakes. The gear ratio is 4.56.
I narrowed the front crossmember to bring the wheels in under the front fenders but the rear axle is the correct width.The spring width was slightly different than the axle spring perches so I made some simple adapters to make everything work.
I am using the standard 19.5 motorhome wheels and this allows the use of modern radial tires rated at 75MPH.
I also used the hydraulic Hydroboost master cylinder mounted behind the cab and actuated through a linkage.There was no room on the firewall for this booster with the 454 in there.

Thank you for the info. I was wondering about that front suspension. I don't now that I would go that route for what I want to do but it is a possibility. A neighbor has both a motorhome and a van to choose from for a front end. I work part-time for a frame shop and could narrow a straight axle too

Fabricating spring perches for a different width rear axle isn't an issue either. I can whip up something. I like the pics I saw of a rolling bag air ride conversion too. That would be nice for a smooth ride and to lower the bed height for loading a car. I had a Pete 379 for 17 years with air leaf suspension and have more experience changing those bags and rebuilding suspension bushings/arms/springs, etc than I care to remember..

The independent front suspension was a lot of work.It rides nice and the handling is good but I would probably find a modern straight axle with disc brakes if I was doing it again.
I am in the process of building a "big" four link rear suspension to eliminate the leaf springs on my truck.I say "big" because I am upsizing all of the normal four link components for this bigger truck.
I have two lobe air bags I will use instead of the leafs and have purchased a semi truck air spring height valve. I am hoping this will allow me to have the same ride loaded or unloaded but I have no experience so it's an experiment.
I have removed many springs from my spring pack and I still don't think the rear end moves at all.
Once I have the bed weight it will help but I think the air ride will still be much better.
Then I plan to convert the front coil springs to air bags also.

Out of curiosity,what is a Pete 379 and "air leaf suspension"?