Welcome to Eric Miller's 1949 John Deere Styled G Restoration Page.

Last Update 03/31/2008  

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Here is a chart of the gear ratios with 13.6 - 14.9 - 16.4 - 18.4 tires on my 1949 John Deere Styled G.

I made a program to calculate the gear ratios of the John Deere G tractors with high and low range transmission. I counted all the teeth on all the gears in the John Deere G to get the ratios and the speeds in each gear with 4 different tire sizes.

Here is a tooth count of all the gears in the transmission of a John Deere G with high and low range.

Primary   Range  

Trans

 1 2 3   Rear   Bull

Teeth

 81   25     28 21 14   78   71
44   21     18 25 32   21   16
                       
    25                  
    21                  

Ratio

 1.840909   1.190476     1.555556 0.84 0.4375   3.714286   4.4375

Here is the overall gear ratios with high and low range of a John Deere G.

Overall                       Totals
1 1.840909   1.190476   1.555556 1 1   3.714286   4.4375
56.18911
2 1.840909   1   1.555556 1 1   3.714286   4.4375 47.19886
3 1.840909   1.190476   1 0.84 1   3.714286   4.4375
30.34212
4 1.840909   1   1 0.84 1   3.714286   4.4375 25.48739
5 1.840909   1.190476   1 1 0.4375   3.714286   4.4375
15.80319
6 1.840909   1   1 1 0.4375   3.714286   4.4375 13.27468

Here is the speed of each gear calculated with STD - 10% - 20% - 30% RPM with 13.6 - 14.9 - 16.9 - 18.4 tires on the John Deere G.

RPM STD

 Tire Size 13.6 14.9 16.9 18.4

1115

 Circum 180 190 198 206
Diam 57.30 60.48 63.03 65.57
         
Rev/Mi 352.00 333.47 320.00 307.57
         
  Speed      
1 3.382449 3.570363 3.720694 3.871025
2 4.026724 4.250431 4.429397 4.608362
3 6.263795 6.611783 6.890174 7.168565
4 7.456897 7.871169 8.202587 8.534004
5 12.02649 12.69462 13.22913 13.76364
6 14.31724 15.11264 15.74897 16.38529

RPM 10%

 Tire Size 13.6 14.9 16.9 18.4

1227

 Circum 180 190 198 206
Diam 57.30 60.48 63.03 65.57
         
Rev/Mi 352.00 333.47 320.00 307.57
         
  Speed      
1 3.722211 3.929 4.094432 4.259863
2 4.431203 4.677381 4.874323 5.071265
3 6.892983 7.275926 7.582281 7.888636
4 8.205931 8.661816 9.026524 9.391232
5 13.23453 13.96978 14.55798 15.14618
6 15.75539 16.63069 17.33093 18.03117

RPM 20%

 Tire Size 13.6 14.9 16.9 18.4

1338

 Circum 180 190 198 206
Diam 57.30 60.48 63.03 65.57
         
Rev/Mi 352.00 333.47 320.00 307.57
         
  Speed      
1 4.058939 4.284435 4.464833 4.64523
2 4.832069 5.100518 5.315276 5.530035
3 7.516554 7.93414 8.268209 8.602278
4 8.948277 9.445403 9.843104 10.24081
5 14.43178 15.23355 15.87496 16.51637
6 17.18069 18.13517 18.89876 19.66235

RPM 30%

 Tire Size 13.6 14.9 16.9 18.4

1450

 Circum 180 190 198 206
Diam 57.30 60.48 63.03 65.57
         
Rev/Mi 352.00 333.47 320.00 307.57
         
  Speed      
1 4.398701 4.643073 4.838571 5.034068
2 5.236547 5.527467 5.760202 5.992938
3 8.145742 8.598283 8.960316 9.322349
4 9.69731 10.23605 10.66704 11.09803
5 15.63982 16.5087 17.20381 17.89891
6 18.61884 19.65322 20.48072 21.30822

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