John Deere A transmission

Bill Marcusky · May 14, 2014

Was wondering if anyone could tell me the ground speed of a 1950 JD A in each gear? My local club rules limit us to 2.75 mph in farm classes and I'm trying to decide which gear to pull in. I have .125 over aluminum pistons with 6.34 compression. Running 93 octane gas with new stock head valves springs ect I ll be in 5500 6000 and 6500 I hope if not I ll def make weight at 6000 6500 and 7000.

Bill Marcusky · May 14, 2014

Also I'm running 13.6 38 tires.

Anonymous-0 · May 15, 2014

If you have a gps like a tom tom you can test it your self that way if you can run a 20% over rpm you can factor that in

ss55 · May 15, 2014

Search for: Nebraska Tractor Test.

Beginning around 1920, Nebraska required every tractor model sold in Nebraska tractor to be tested at a test track at the University of Nebraska in Lincoln, NB. The performance data of each tractor is published and available on line.

I don't have the link handy, but it has been posted on this site many times and is easy to find with google.

ss55 · May 15, 2014

Test #384 is a 1947 John Deere A. I think you 1950 A has slower gears than a 47. Sorry.

730-LP · May 15, 2014

1st is going to be around 1.5 and 2nd 2.5 to 3 not meaning to be ugly but if only 6.34 to 1 compreeion you don't need 93 octane,and with only around 35 hp.2nd in 5500 and 1st in heavier class.Its not how fast you go but how FAR and most of all have FUN, if you go expecting to win you may come home disapointed,if you go to have FUN and win you have had a BLASTTTT.

Dblair · May 15, 2014

1st 1.5 second 2.5 third 3.5 fourth 4.5 fifth
5.75 sixth 10 . all these are on 11.38 rears .

forty40 · May 15, 2014

(quoted from post at 21:36:17 05/14/14) Was wondering if anyone could tell me the ground speed of a 1950 JD A in each gear? My local club rules limit us to 2.75 mph in farm classes and I'm trying to decide which gear to pull in. I have .125 over aluminum pistons with 6.34 compression. Running 93 octane gas with new stock head valves springs ect I ll be in 5500 6000 and 6500 I hope if not I ll def make weight at 6000 6500 and 7000.

There's a few handy conversion calculators on-line like the one below that you can easily use to quickly find your mph.

www.google.com/#q=ft/sec+to+mph

Drive the tractor at steady state speed for 10 seconds in a straight line, measure distance traveled, divide by 10.

So, if the tractor travels 73.3 ft, that's 7.33 ft/sec which is 5 mph.

Any amount of time traveled in seconds can be used, just divide the distance by the time in seconds. Using less than 10 seconds may not be very accurate and if using more time, you'll need to have a good long driveway or field close by. Nowadays there's online calculators for just about everything except multiplying money, they only subtract.

north puller · May 16, 2014

With the 13.6 tires your speed will be:

1st gear@975 rpm: 1.55 mph
1st gear@1115 rpm: 1.77 mph
1st gear@1226 rpm: 1.95 mph

2nd gear@975 rpm: 2.58 mph
2nd gear@1115 rpm: 2.96 mph
2nd gear@1226 rpm: 3.25 mph

gtx1967jewison · May 16, 2014

With that low compression you'll make more power on 87 octane.

Bill Marcusky · May 16, 2014

Thanks that was really helpful.

John Deere A transmission

Bill Marcusky

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Bill Marcusky

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Anonymous-0

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ss55

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ss55

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730-LP

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Dblair

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forty40

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north puller

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gtx1967jewison

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Bill Marcusky

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