Gear Ratio's

[40Club]

Anyone have any idea what gear ratio's for 2nd and 3rd are for 1950 Plymouth Manual Stick Transmission, short transmission out of Business Coupe.

[Plymouthy Adams]

first ----2.57 to 1

second ----1.83 to 1

third ----1.0 to 1

reverse 3.48 ---1

 

 

Edited November 6, 2020 by Plymouthy Adams

[Loren]

1st is 2.57, 2nd is 1.83, and high gear is of course 1 to 1

Of all the transmissions available the only optional ratio is the 1940 model 2nd gear which is 1.55.

Which are available on eBay brand new old stock.

Mopar #692687 2nd gear

Mopar #853885 Cluster

There is a whole 1940 gearbox on there now for $150. A good price for 2nd gear and the cluster is about $200 if you want to change.

Like anything on eBay you have to be patient.

[Plymouthy Adams]

you are overlooking the hy-drive gear ratios....they are 2.37; 1.68; 1.0; rev 3.73.1  with the application of the torque converter...the gearing was able to go to a higher set along with the rear gear being higher for a total combination of better gearing.  You add this to the OD offered later and you truly have a spiffy set up...

Edited November 6, 2020 by Plymouthy Adams

[Mopar-Boy]

I used specs from my tire size and gear ratios for the S10 T5 and what I "believe to be" ratios for my 1933 three speed.  The target RPM below is just where I would prefer to stay below more often than not on my 201 flathead which I hope to keep in place as long as it will permit me to do so!

 

Tire	6.00 X 16
Tire Diameter	28.36
Tire Circumference	89.10
Tire Revolutions/Mile	711.15
	Ratios	Motor Rev/Mile	Speed Miles/Mn	Speed Miles/Hr
Diff Ratio	3.73
T5 1st	3.78	10,026.74	0.25	14.96
T5 2nd	2.18	5,782.62	0.43	25.94
T5 3rd	1.42	3,766.66	0.66	39.82
T5 4th	1	2,652.58	0.94	56.55
T5 OD	0.72	1,909.86	1.31	78.54
Factory Diff Ratio	4.375	Ratio numbers sourced on P15-D24 site under "gear ratio's" forum post
DP6 1st	2.57	7995.95332	0.31	18.76
DP6 2nd	1.83	5693.616566	0.44	26.35
DP6 3rd	1	3111.265883	0.80	48.21
Target Max RPM	2500

[Sniper]

The math seems off to me.  Third gear with the stock trans and 4th gear with the T5 are both 1:1 but the speed values differ? 

 

What am I missing?

[martybose]

40 minutes ago, Sniper said:

The math seems off to me.  Third gear with the stock trans and 4th gear with the T5 are both 1:1 but the speed values differ? 

 

What am I missing?

You missed the different differential ratios, 3.73 versus 4.375

 

Marty

[Mopar-Boy]

correct.  I used a 3.73 mopar diff since going w a T5 requires e-brakes on the axle.  On my spreadsheet, I can change to 4.10 or other.  The 3.73 seemed to work the best given both end points, 1st and OD.

[kencombs]

1 hour ago, Mopar-Boy said:

correct.  I used a 3.73 mopar diff since going w a T5 requires e-brakes on the axle.  On my spreadsheet, I can change to 4.10 or other.  The 3.73 seemed to work the best given both end points, 1st and OD.

I really doubt that I would be happy with a 201 engine with that gear combination.  A 3.73 ratio would restrict use of OD with the 201.  The lower geared rear end would make a better driver I think.

 

But, that version of the T5 and your original rear gears would be cumbersome to drive in town, low and second are rally low when multiplied by the low rear gear set. Probably be shifting twice to cross one intersection.

 

I'm planning on an A833OD with a 3.09 first gear and am concerned with that and a 4.11.  The 3.73 just seems too deep for me.

 

 

A T5 with a higher 1st and 2d with the original rear would be a better driver, IMHO.

 

As far as a park brake, backing plates for a rear end with mechanical park brakes can be adapted.  Or, there is a pinion yoke mounted disk brake available.  I have one, (not installed yet), but I don't know a new source.  I may not use mine as the backing plate swap may be easier than constructing brackets.  All I need to find for that is any rear with 10" brakes.  Adapting the center hole size and drilling 4 mounting holes shouldn't pose a big problem.

 

Just my thoughts.

[Mopar-Boy]

I have the mopar axle and the rebuilt T5, but have not purchased ring and pinion.  Here's the chart using 4.10 gears.  Also, thought about backing plate option but the rear of the tail housing on T5 is right where the x bracket is on the frame so not really an option.  Thanks for the feedback.  Exactly what I was hoping for.

 

Tire	6.00 X 16
Tire Diameter	28.36
Tire Circumference	89.10
Tire Revolutions/Mile	711.15
	Ratios	Motor Rev/Mile	Speed Miles/Mn	Speed Miles/Hr
Diff Ratio	4.1
T5 1st	3.78	11,021.35	0.23	13.61
T5 2nd	2.18	6,356.23	0.39	23.60
T5 3rd	1.42	4,140.29	0.60	36.23
T5 4th	1	2,915.70	0.86	51.45
T5 OD	0.72	2,099.30	1.19	71.45
Factory Diff Ratio	4.375	Ratio numbers sourced on P15-D24 site under "gear ratio's" forum post
DP6 1st	2.57	7,995.95	0.31	18.76
DP6 2nd	1.83	5,693.62	0.44	26.35
DP6 3rd	1	3,111.27	0.80	48.21
Target Max RPM	2500

[kencombs]

5 minutes ago, Mopar-Boy said:

https://www.borgeson.com/xcart/home.php?cat=2&page=1Target Max RPM	2500

 

The backing plate option I referred to is not on the transmission.  It is a replacement of the rear brake backing plate, and associated parts with those that include a mechanical park function.  The only sticking point in that would be selecting a plate that places the shoes in the correct relationship to the drum.

[Mopar-Boy]

With 3.91 gears I'm only spinning 2500 RPM at 14.3 MPH.  And no matter what, going uphill or into the wind (it's a brick) w the original 201 at anything over 55MPH probably "ain't in the cards" regardless of gears!  I want reliability, great stopping (disc brakes, radial vintage w wire wheels already on it), 12v (next project) and want to retain the essence of a 1933 sedan.  And by the way, I probably like working on them even more than driving them!  Getting the vacuum wipers to work was a whole new experience...

 

I have a 65 hemi fastback coronet (clone) with a 572 hemi to address any need for speed.  My DP6 is for weekend drives, out w the grandkids, etc.  Both cars are an excuse to spend time on the floor of my garage w the wrenches and the grease...

 

	Ratios	Motor Rev/Mile	Speed Miles/Mn	Speed Miles/Hr
Diff Ratio	3.91
T5 1st	3.78	10,510.60	0.24	14.27
T5 2nd	2.18	6,061.67	0.41	24.75
T5 3rd	1.42	3,948.43	0.63	37.99
T5 4th	1	2,780.58	0.90	53.95
T5 OD	0.72	2,002.02	1.25	74.92

[Mopar-Boy]

I meant "hardtop" not fastback... (sorry)

 

[Bobb Horn]

On 1/27/2021 at 12:46 PM, kencombs said:

I really doubt that I would be happy with a 201 engine with that gear combination.  A 3.73 ratio would restrict use of OD with the 201.  The lower geared rear end would make a better driver I think.

 

But, that version of the T5 and your original rear gears would be cumbersome to drive in town, low and second are rally low when multiplied by the low rear gear set. Probably be shifting twice to cross one intersection.

 

 

I am very happy with my setup, 82 hp, 218, tko ranger 5 speed from a 1987, 3.73 rear from a 95 ranger.    I live in hilly virginia, so the 3.73 rear works good, but I believe a 3.55 rear would be better on the highway, even though I can cruise at 60mph with no strain on the drive train.    In our little town, the coupe handles stop and go, up and down, with ease, and is a pleasure to drive with the changes...

[Mopar-Boy]

Thanks Bobb!  Great looking plymouth!  Do you happen to know the ranger 5 speed gears?  I'm in Atlanta, so we have hills as well.