Which Tranny.

[cranker]

As i have posted i am in the middle of building a tractor. I was planning on using a c4 auto but now i am starting to rethink it. I have a 4 speed amnual for it also. Looks like i am going to be adding a transfer case to it to get some better gearing. It will have a fel on it when it is done.
Which tranny do you recommend manual or auto?

Thanks Crank

 

[MRCONCDID]

not to be a smartaxx but how many automatic transmission tractors have you seen? cvt and hydro trannys are not automatic transmissions.
I think you will like the manual tranny better. you will have way more control, not only gearing up and down but to hold a gear so not to go to fast and to slip the clutch when going into a pile of dirt or snow, you cant do any of this with a full auto trans. I know you can hold a gear in an auto but you cant easy into a gear like a manual. go with what works.
I hope this helps, I love the project keep us posted on it.

 

[Soundguy]

what ya doing for a pto? xfer case from a powerwagon?

soundguy

 

[cranker]

Thanks mrcon, that is kinda what i was thinking also. just like the ease of use with the auto. just getting lazy i guess..

No pto at this time. if i decied on wanting one i can use the front output on the tcase and get a rear shaft disconect.

 

[carpenter383]

I don't see why u couldn't ease into something with an auto, it has a torque converter, you can stop in gear if you want.
If you use an automatic you need good brakes! Less engine braking on hills, and no engine braking in when not running.
The biggest problem I see with running an auto (especially a relatively weak c-4) is HEAT. Auto tranny's don't like heat! With low travel speed to cool the fluid and the high loads that tractor duties require it's just a matter of time and it'll be slipping.
If you use a manual you could try and find one with pto(s) built into it so you can adapt a hydraulic pump or whatever more easilly.
I would think a 4x4 granny lo 4-spd with a transfercase in low range and really low rearend gears would be minumum just to get an aceptable ground speed in the lowest gear. Lets see if you had a 4-spd with 6 to 1 first a transfercase with 2 to 1 and a 5.00 gear you're looking at 60 to 1 overall. In this example your rear wheels would turn once for every 60 times the engine turns.
With an auto you'd be lucky to get half that unless you ran 2 transfercases or something.
A tractor ain't much of a tractor without really low gears! JMHO

 

[LAWALLSTRACTOR]

Run the automatic tranny to a 3 or 4 speed manual tranny and then to the rear end. This will give you a 3 or 4 range automatic transmission, with a large speed range from a crawl to highway speeds.

 

[Renze]

not to be a smartaxx but how many automatic transmission tractors have you seen?

Most high horsepower tractors have the components of automatic transmissions: An automatic is just a powershift with a torque converter in front.

When you stall the converter, it will turn its full input power into heat. make sure you have the cooling capacity.

 

[Soundguy]

...and you see very few tractors with torque converters.. I think that was MRCONCDID's point.

I can think of a couple.. but that's it..

soundguy

 

[BHD]

I think a lot will depend on how one plans on using it,

I you want a power down shift if it gets tough pulling then a automatic may be a good choice, but I would think you would want a manual transmission behind it for the basic gear/speed range, so the auto would normally run in high and the torque converter would not be slipping much,

at one time through racing outlets they made a clutch kit that would replace the torque converter, and then basically you have a power shift,

another thing most would want is a governor for the engine so you can hold it at one speed/ rpm. (some old gas combines used a belt driven Governor that would control the carburetor, and then a bar would be used to slow the engine down or a spring attached to the govern arm to create more Resistance for the Governor to work against)

IF I was going to make a PTO for some thing like your making I would probably do either a electric clutch or a belt clutch and drive it off the front of the engine, and then off that shaft the hydraulic pump,

IF you use a transfer case I would lock it in low range and leave it or use some thing Like I suggested in the other post and drive some combine final drives, with the differential,

My concern here is for safety, I know how kids are, (big kids some times are not much better), and they will want to drive a small tractor, and most people if related will give in, but if you have a tractor that can go 60+ mph, you have some real potential problems, and if there is a way of shifting it to high they will find it.

Personally I would opt for the manual transmission, unless I was mostly going to be using it for start and stop chores, such as building fence, the automatic would be great for loader work as well,

we have a old fork lift and parts are very rare for it, (1950's) and we have considered remaking it if we lose the engine, or transmission components, to use a automatic and then some type of drop box to power the differentials or use if we can find a combine hydrostatic and put in between the differentials and then belt drive off the motor, the fork lift is 4 wheel drive.

but regardless get geared lower (I would not want top end over 20mph),

 

[carpenter383]

I think a lot will depend on how one plans on using it,

I you want a power down shift if it gets tough pulling then a automatic may be a good choice, but I would think you would want a manual transmission behind it for the basic gear/speed range, so the auto would normally run in high and the torque converter would not be slipping much,

at one time through racing outlets they made a clutch kit that would replace the torque converter, and then basically you have a power shift,

another thing most would want is a governor for the engine so you can hold it at one speed/ rpm. (some old gas combines used a belt driven Governor that would control the carburetor, and then a bar would be used to slow the engine down or a spring attached to the govern arm to create more Resistance for the Governor to work against)

IF I was going to make a PTO for some thing like your making I would probably do either a electric clutch or a belt clutch and drive it off the front of the engine, and then off that shaft the hydraulic pump,

IF you use a transfer case I would lock it in low range and leave it or use some thing Like I suggested in the other post and drive some combine final drives, with the differential,

My concern here is for safety, I know how kids are, (big kids some times are not much better), and they will want to drive a small tractor, and most people if related will give in, but if you have a tractor that can go 60+ mph, you have some real potential problems, and if there is a way of shifting it to high they will find it.

Personally I would opt for the manual transmission, unless I was mostly going to be using it for start and stop chores, such as building fence, the automatic would be great for loader work as well,

we have a old fork lift and parts are very rare for it, (1950's) and we have considered remaking it if we lose the engine, or transmission components, to use a automatic and then some type of drop box to power the differentials or use if we can find a combine hydrostatic and put in between the differentials and then belt drive off the motor, the fork lift is 4 wheel drive.

but regardless get geared lower (I would not want top end over 20mph),

The torque converter would slip most in high gear and the least in low gear. The ammount of converter slippage depends on load. In low gear there will be less load on the engine/trans. than in a higher gear.

 

[cranker]

Okay guys the decision has been made.
First i would like to think everyone for the input i really appreciate of all of the thoughts.
I am going to go with the 4spd m/t and also with the sammy tcase. i got the tcase today and it is so cute. Not very big at all an i tthink it will give me much better gearing options and still keep the wheel base with in reason.

I figure i will have to redo the tranny mount again so why not cut the back half of the tractor off and redo that too.. lol

I will try to get some new pics and update the thread.

Thanks Crank

 

[Mace Canute]

I'm not positive but from what I can find the pinto 4 speed gear ratios are: 1st = 3.65, 2nd = 1.97, 3rd = 1.37, 4th = 1.00, Reverse = 3.66 and the Samurai transfer case ratios are 2.268:1 in low range and high range is 1.409:1.
With a 5.14 differential gear and 29 inch tall tires, your slowest ground speed will be 4.1 mph @ 2000 RPM (and a fastest ground speed of almost 24 MPH. ) By going to a 7.00:1 ratio gear set in the rear, you can get that down to 2.9 MPH. To get a ratio that high, you would definitely have to go aftermarket. I suspect you need more reduction than what you will have with your present setup. (BTW, here's a couple of sites for a speed calculator... 4Lo.com :: Final Gear Ratio, Crawl Ratio, Tire Size Calculators
Speed Potential Calculator For Ring Gear And Pinion Changes)
If you could find a T-18 or T-19 wide ratio transmission, they should have a granny low gear of 6.32:1. With that tranny you could get a speed of 2.3 MPH with the 5.14 gears and 1.7 MPH with the 7:1 gears. Maybe try to find a transmission and transfer case that are already married to each other to ease the installation? Boy! The possibilities are almost endless! btw, you probably won't want a spool in the diff.

 

[BHD]

The torque converter would slip most in high gear and the least in low gear. The amount of converter slippage depends on load. In low gear there will be less load on the engine/trans. than in a higher gear.

yes if keep in low you will have less slippage as you have less torque being transfered in the converter unless you have tires that can not slip, I did say that wrong, but the bigger key is the engine RPMs, (even tho I do have a truck with a automatic transmission that is locked solid in third and forth gears and only uses the torque converter in the lower two gears, it was made in 1952).

but if you lug the transmission and most transmissions will jump in to drive very quickly if it is a light load, but if the RPMs of the engine is up, the torque converter will be solider than at lower RPMs and on most tractors you want to run the engine up to its operational RPM, which is normally what would be some below red line in a cars engines situation.

you need to keep the engine above the stall speed of the torque converter,

yes in a cars situation the Rpms of the engine are extremely variable in a tractor they are not, and do to that variable nature of the car there is a lot of slippage in the torque converter, as most auto automatic transmissions do not down shift unless one stops thus they remain in the drive gear, usually only down shifting into second when the vacuum and the throttle lever is moved and kicks it into "passing gear" second,
so unless one put it in a gear and leave it there defeating the automatic nature of the transmission,

the key to the converter is keeping the engine Rpms up above the stall speed of the converter, and very little slip will occurs,

HP25LFUEL - Hughes Torque Converter, Fuel Miser 1200 RPM Stall Speed - HP25LFUEL
Stall speed is the point where a converter has reached it's maximum fluid flow or it has hydraulically locked up because torque multiplication has reached it's highest point.

the higher the stall speed of the converter the more heat would be produced in a variable engine operations, were the engine was operating at or under the stall speed. operation above the stall speed the converter is nearly locked but below the stall speed the convert works to multiply the torque of the engine. but heat is a by product of that torque,

 

[carpenter383]

Yes I agree you need to keep the engine in it's "power band"
But just because the engine is turning 2000 rpm and the converter is rated to stall at 1500 rpm dosen't mean it's not slipping, it could be slipping alot.
There are two main reasons:
1. A 12" 1500 stall speed converter for a 1/2 ton pickup with a 175 horse 305 engine may stall around 1500 rpm. But if you yank the 305 and replace it with a 502 CI big block it may stall at 2000 rpm (assuming the tires don't spin and the trans dosen't slip) So stall speed is directly related to the ammount of power your turning the converter with.
2. Stall speed is based on engine speed and input shaft speed and is rated with the input shaft at 0 rpm and wide open throttle. So if the input shaft is turning 1000 rpms and the engine is tuning 2000 rpms under full throttle the converter is slipping and making ALOT of heat. The closer the converter is to "stalling out" the more heat it's producing. A light load will result in low slippage compared to a hard load regardless of engine rpms.
This is why basically all auto trannies from the past 25 yrs or so have lockup converters. There is a clutch in the converter that locks the crank to the input shaft and eliminates slippage while cruising down the highway at light throttle. Better feul milage, lower tranny fluid temps. and lower engine rpms.