1952 truck tranny

[Patriot1]

Guys, I'm new here and could use a little help. I just picked up a '52 Chevy truck with a stock 235 and a 4 speed. I'm told the tranny actually came out of a bus and it's geared so low I can start off in 3rd gear. At about 45 mph it's screaming like my ex-wife with the fuse on her tampon lit The trucks going to be a daily driver so I need to be able to get up to highway speeds comfortably. Any suggestions as to what 4 speed tranny I can drop in there to match up to the stock 235? Any suggestions would be greatly appreciated. Thx.

[msaintg]

I don't know squat about the original stuff, so take this for what it is worth..... I thought I heard guys say that problem is not the fault of the tranny as much as it is a problem with the gearing in the rear end.

[mr48chev]

If it's a 3/4 ton or larger the rear axle may have 5 something gears that will allow it to pull anything you hook it to but are real slow on the road. While it could idle around a hay field picking up bales without a whimper it would be really slow on the highway.

[Patriot1]

Thx for the replies. It's a 1/2 ton. Here's all the history I have on it. A railroad worker drove it into a NC town to work on the new railroad coming through in the late 50's. It overheated when he got to town and wouldn't turn over after that so he sold it to a local mechanic. The mechanic rebuilt the 235 motor and, for some insane reason, installed a tranny from a bus. I don't know (yet) what rearend is in it. I'll have the truck on Thursday and will try to identify the tranny and the rearend this wekend.

[Yewhi]

I'm sorry... I'm still picking myself off the ground after the ex-wife comment. LMAO! Now... What was the question again???
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[Root2812]

You may be mistaken on either what you have or the story. The 1/2 ton didn't come with a 235, it came with a 216. The big trucks and busses came with a 235 but it was a splash oil system like the 216. Don't mistake that with the 235's guys swap in because those are the 1957+ with full pressure oil system. So either you have a non-original motor or you have a 216.

The 1/2 ton came standard with a 3 speed on the column but the 4 of the floor was an option. Infact my 1/2 ton has the 216 with the original 4 on the floor. Its most likely a SM420 if its original and could be either that or maybe a Saginaw if its been swapped. Do you have the remains of a column shift on your steering column? If not then I would bet you have the original sm420.

My truck will go 50 mph but the motor is screaming. That has a lot to do with the factory 4:10 gears in the torque tube rear end and not so much the tranny. The sm420 has a very low 1st gear to where you don't even need to use it unless you are pulling out stumps but the 4th gear is very similar to the 3rd gear in the 3 speeds. These trucks were ment for farms and not highways. If you want highway speed your best bet would be to find a 1957+ 235, a t5 5 speed (s10's had them), and an open drive rear end. All those parts are cheap and would give you a more streetable set up.

[Patriot1]

Great info Root, thx. The column does not have the remnants of a shift lever so I believe the truck came with a 4 speed, just not the one that's in it now. The motor is not original. It was changed recently to a newly rebuilt 235 but I don't know if it's a '57+ or not. Will the serial number tell me that? The t5 and RE swap seems like the way to go. I know very little about rearends except for the basic gear ratio's. Can you give me a little more info on what to look for in an "open drive" rear end? I really appreciate the help.

[_Ogre]

i don't know of a transmission that isn't 1:1 in high gear unless it is OD unit
your top speed is limited by your rearend

[Root2812]

You should be able to learn what motor you have from the casting numbers.

For rear ends you really have 2 types: The torque tube and the open drive (this may not be the official term). A torque tube has the drive shaft inside a tube and fixed to the rear end where an open drive rear end has a driveshaft with U-joints. If you look under any modern truck you will see an open rear end. Some guys get the rear end out of a 4x4 s-10 rear end and some (like me) get the 3:73 rear end out of an explorer.

I have my explorer rear end out back so I haven't put it in yet but many here have because its very close to the right width. As you can guess, with the s-10 rear you keep a GM wheel bolt pattern where with the ford you don't. This works out for me because I am going to swap to a mustang II front suspension anyways.

[Patriot1]

Thanks for the info Root. I'd rather keep the GM pattern so maybe the 4x4 S10 rearend is the way to go. I'll see what I can find and post an update when I have one. Thx again.

[Patriot1]

I've found a rearend from a 97 Blazer 4x4. Is this a rearend that should easily bolt up to my '52?

[1project2many]

i don't know of a transmission that isn't 1:1 in high gear unless it is OD unit

Ooh! Ooh! Trivia time!

Many front drive transaxles do not have a 1:1 gear ratio. They use a two shaft design rather than a third input shaft like used in a rear drive transmission. Power flows into the main shaft and out of the countershaft so the input shaft cannot be locked to the output shaft to give a 1:1 ratio.
http://www.calgaryfieros.com/OSGdocs/tranny.html

I've found a rearend from a 97 Blazer 4x4. Is this a rearend that should easily bolt up to my '52?

Someone else can answer that, but if you use a 98-2002 Blazer rear axle it will come with factory disc brakes. If you want to stay with a drum rear, dump the 9.5" drums and use 11" rear brakes from a 73-77 A / G body (Malibu / Monte Carlo). You might have to piece it together with '89 Caprice backing plates and drums for the older car but it will be better stopping either way.

[53farm]

I have a '53 3/4 ton that in a weird way seems to have both. The drive shaft/rear end joint definitely has an open/visible U joint just like a "modern" vehicle. The portion of the driveshaft behind the carrier bearing is exposed and looks just like a driveshaft in a modern vehicle. However, where the drive shaft goes into the 4 speed manual transmission there is no visible joint and that area is enclosed by a "bell" housing of sorts. I'm new to these trucks too so please excuse my ignorance as far as terms go. The drive shaft also is supported by a carrier bearing about half way between the transmission and rear end. I assume this thing has been messed with at some point then if the torque tube doesn't extend all the way back, and the fact that it has the exposed U joint at the rear end. Is that correct?

As I've posted here before, my ultimate goal is to convert mine to 4WD but retain the original frame, which is in good shape as far as I can tell. The motor in mine also appears to be the 250 6 cylinder from a early to mid 70s vehicle. Can a transfer case be added to my current transmission with that enclosed rear joint, or would I need to swap to a different transmission that didn't have that enclosed rear portion? Didn't mean to hijack the thread, but I'm wrestling with some of the same questions as the original poster. Thanks, and good luck with your '52!