The Stovebolt Site Forums The Shop Area Engine Shop 1950 3/4 Ton Rear End Swap

I have a 1950 3/4 Chevy pickup with a current 5:10 gear ratio. I would like to change thange that out to something that I can drive faster on the roads with.

Does anyone sell after market ring/pinions with a better gear ratio? Is there a compatible punkin that I can swap with or do I need to get a whole new rear end setup? Thanks for your help on this.

yes
The answer is out there do a search. About the best gears you will find are 4.11. I won't tell you where to find em... if you can find em. Get used to doing a search, as this has come up many, many times before. I believe your rear end is called an Eaton HO52 or HO72. I only mention those numbers because it might help you do a search.

John

PS. Welcome to the Stovebolt page, and sorry for jamming you. If you are still having trouble finding the info you need, PM me and I'll send you a link to some of the previous discussions on this topic.

Todd

I do have 1952 3/4 ton, I guess it has 4.54 rear end. 69 Nova rear end or Ford 9 inch would also work, Anything from that era which has about 60" around that should work with 3.55 gears

There is actually a thread which lists all the rearend lengths, if I find it I will copy it

Ganesh

The 4.10 ratio rear is the holy grail for us 3/4T owners. The other common, stock ratio is 4.57 (that's what I have). One of those should be easy to find, and is an easy replacement. Don't even have to remove your tires! Just unbolt the axle-centers and pull them out a couple inches (disengage them from the diff). Undo the yoke from the drive shaft, then unbolt the whole pumpkin from the axle housing. Don't drop it on your head or anything! Then, jack up the replacement pumpkin and reverse the process (you did get the whole pumpkin, right? Either it was good when you got it, or you took it to a shop for tweaking). Slide the axles back in, turning them to engage the splines. You may have to lift the wheel now to turn it to line up the hub bolt holes.
If you want a lower ratio, you can add an overdrive (My plan) or find an 8-bolt rear axle the right length from a newer truck with a better ratio and change the whole thing. That would give you newer (easier to service) brakes and would be a fairly easy swap as well.
Good luck with your hunt.

There is a problem using car rearends in a truck, The truck will no longer be able to cary any weight or load. True you can get higher gears, but you lose the load rating of your truck. There is a reson the factory put those big rear ends with the huge bearings in there in the first place... to cary weight. The type of swap mentioned above is more in the line of acceptability in a 1/2 ton truck, but not a 3/4 ton truck that may be asked to work.

Well I agree to big...daddy about the load carrying ability. In my case I dont need my antique to carry load, I have newer truck. This one is only for fun so it worked for my purpose

Ganesh

Rather than a 9' then, why not use a Spicer 60 from a late model 3/4 ton van? Dodge van rearends are the right width, and are common with a 3.55 gear, plus keep the bolt pattern. They are semi-floaters, however, so there is some stength reduction, but it still a far stronger rear than a 9" for a truck application.

Actually, there are aftermarket full floating 9 inch rears available, with disc brakes for reasonable money. I know for fact you can get them in a 6 lug configuration because I have bought 2 of them. I have never asked about the 8 lug on 6.5 inch circle. The full floating axles do not carry the weight of the vehicle, they only transmit torque, so they can be built plenty strong.

We are getting off topic here as the original question asked about gears or a pumpkin that will interchange with the original axle. We all know there are higher gears than 5.14 or 4.56 available for those rears. What we don't know is how Todd K plans to use/drive his truck.

I do know about the aftermarket floaters and parts for the 9", and I'm certain you can get whatever bolt pattern you want for one, but I'm thinking more about easy and cheap parts the average guy can get at the local salvage yard without spending a bunch of hard earned cash.
Not trying to start an argument or anything, just pointng out the easiest and least expensive way to do things and still retain some capacity.
As far as interchange, Chevy used the same axle for 3/4 and 1 ton up to '72, with a 4.10 gear available from '68-'72 in 3/4 tons with automatic.

If you have a wrecking yard around with older trucks, look for 76-72 3/4Ton trucks. Check the ratio if you can, either by counting teeth or by spinning the wheel. If you get a 4.57 out of a later truck, you are half way there. On occasion, Randy's Ring and Pinion show a 4.10 gear set as available, but they can only go in the later pumpkins. Search Eaton HO-72 on their site.
When I mentioned swapping to another 8-bolt rear, I should have said 8-lug. I agree, a car rear doesn't belong under a 3/4ton truck.

I made the swap to the 4:11s, WOW what a differance in every gear. Found the gears via an ad here on the bolt. But, I believe there must be a zillions of these out there as these trucks are still on the road in huge numbers. I was told the 4:11s were in the truck with automatic trans. So you need to really beat the bushes and I'm sure you'll find a set. I'm sure most people with these trucks nowdays do not realize the need for these parts expecially ease of interchange in older trucks.

lol Who pooped in your cornflakes?
what a grumpy old fart you must be, does it really bother you thatyou keep reading posts by new people here? If you dont like them asking the same questions, dont click on the link. simple as cake(easy as pie)

And anyhow, the search sucks, it doesnt give the results as topics, but every single fricking post in every single topic that had the key word. so, you have to filter through lots of pages just to TRY to find some relevant information. When instead, someone who has the answer could easily spend just a few seconds and type which rear end fits(btw thanks jimerit)(if of course they feel that they arent far too important to help out a fellow 'bolter).
Common questions are going to be asked more often, so deal with it or go read a book, unless busting noobz ba!!s is your favorite pastime.

As a owner of a 1946 ¾-ton Chevrolet, full floating axle, I have found this thread of interest. Not that I will be working on it in the near future, but have upgrade plans for the future. This is not an attempt to hijack the thread. But since we are on the topic of swapping ¾-ton rear gears, I’m confused as to the topic. When you talk of the swap are you talking about the entire rear axle, (brake shoe to shoe) or just the carrier assembly, bolting directly into the axle, maintaining the factory brakes? I did a search on rear axle-shafts on e-bay and found that the axles are the same from 1946-1972?

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=380113947103

My thoughts are now if, the carrier assembly was a direct bolt-in, this a money saving junk yard find. Did I get it right gentlemen?
Dale

I have always thought that it was 1947, maybe second series to 1972 but I could be wrong. The swap involved the center section only which comes out the front. It is sort of shaped like a pumpkin and so it is sometimes referred to as such.