Speed chart for Late A tractor?

wilamayb · Jan 25, 2015

Dad says he cant find his operators manual (I sure think it's there). Does anyone have one handy to offer tire size and speed chart for gears 2 and 3 on a single stick shifter A tractor? I was wanting to get some orifices to put down some liquid N but I needed to know a speed range to choose the correct one..

I sure would appreciate it.

Juicybusa2 · Jan 25, 2015

An inexpensive handheld gps is your best bet for accuracy

Pete in MD · Jan 25, 2015

On 38" tires 2nd is 2.5 mph and 3rd is 3.5 mph.

wilamayb · Jan 26, 2015

Thanks Pete, but which size 38" tires? 11.2, 12.4 or 13.6? Was that for the very late single stick shifter tractor?

Pete in MD · Jan 26, 2015

Yes, those speeds are for a late styled A after ser# 648000(mid-1950).

Tread width doesn't make any difference.

coonie minnie · Jan 26, 2015

If you have a tape measure and a watch, you can get a more exact read on ground speed... and it will be matched to your tires and engine speed.

If you measure 100 ft, and then time the number of seconds it takes to drive that distance, we can help you with the math.

Good luck.

BushogPapa · Jan 26, 2015

"Late A"..according to my Data Book (Lorry Dunning) says, with 11x38" tires (12x38" now), 1st gear== 2.5 mph and 2nd== 3.25 mph....

# 648000 and up were to be made with the "Creeper Gear" 1st gear and revised cylinder head..
I see no listing for gear speeds on the Creeper Gear tractor..

Ron.

wilamayb · Jan 26, 2015

Thanks guys, yeah I'm not where the tractor is so I cant run a physical test. That's the whole problem, but I am in the town where the orifices need to be purchased. I have no issue with the math. The problem that I had was too many "Xs" in my equation.

wilamayb · Jan 26, 2015

Pete, thanks again for the help but tread width wasn't my concern. Overall tire diameter of the speeds given in the chart was my question. There's quite a bit of height difference between an 11.2 and a 13.6. 4.5 inches to be exact..

Bob Harvey · Jan 26, 2015

I'm not sure about your 4.5 ", BUT, the height difference between an 11.2 and a 12.4 x 38 is 3/4". How do I know this ? That's what I have on my 60 and used a level. This is only a measurement. The tires are of different ages and I suspect wear to be a factor, that said, tread depth is within 1/4". So, 3/4" +/- 1/4" on my deal.HTH

wilamayb · Jan 26, 2015

I got my numbers from Firestone using the same model tire for each size. It's hard to compare while mounted due to inflation differences.

coonie minnie · Jan 26, 2015

Low on those was 1.5...

Frank 41 · Jan 26, 2015

I used my Garmin that will give me tenths. I am supposed to run 5 MPH at Rantoul, which is hard to put put that slow. So when I get close to the crowds, I know when to go back to 5th.

Lee B · Jan 26, 2015

Even if you got a good book number it would probably be a no load speed and as such it might not mean a thing with a load on the tractor and in the field working. Best to tie onto the injector, sink it in and use GPS to get an actual ground speed number would be my advice. If they wanted to play like good guys they might be talked into sending you home with a range of orifices that should cover it for you. With the idea that you will return the ones that aren't what you needed for a refund.

BushogPapa · Jan 27, 2015

Tire Height and tread width vary from one manufacturer to another for the same exact tire size numbers...

Speed chart for Late A tractor?

wilamayb

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