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1941 V8 Transmission gear ratio

Started by Ohjai, February 16, 2021, 04:13:30 PM

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Ohjai

I have searched the web, data book and service manual to find the transmission gear ratio for the three speeds.  I found the rear end is 3,77:1.


For the 38 V8 1st = 2.39:1, 2nd = 1.53:1, and 3rd = 1:1,; with the rear end at 3.92:1


Where else can I search for the data?


Jim
'38 Cadillac Series 60 S
'41 Cadillac Series 60 S
2017 Cadillac CT6
'62 Buick Skyhawk Conv
'49 Bentley MK-VI  Sold
'53 Bentley R-Type  Sold
'66 Ford Thunderbird
'64 Rolls-Royce Silver Cloud III
'75 Rolls-Royce Silver Shad Sold
'78 Rolls-Royce Silver Shad II
'80 Rolls-Royce Silver Wraith II  Sold
'81 Rolls-Royce Camargue  Sold
'88 Rolls-Royce Corniche II
'89 Rolls-Royce Silver Spur
2020 Ford Escape

harry s

The transmission gear ratios for '41 should be the same as '38. That's why there is probably  not a listing the the '41 books. The master parts book lists gear sets for '38 thru '48 as the same part number.     Harry
Harry Scott 4195
1941 6733
1948 6267X
2011 DTS Platinum

Ohjai

Thanks Harry, I should have looked in the parts book, my mind just did not go in that direction.


Jim
'38 Cadillac Series 60 S
'41 Cadillac Series 60 S
2017 Cadillac CT6
'62 Buick Skyhawk Conv
'49 Bentley MK-VI  Sold
'53 Bentley R-Type  Sold
'66 Ford Thunderbird
'64 Rolls-Royce Silver Cloud III
'75 Rolls-Royce Silver Shad Sold
'78 Rolls-Royce Silver Shad II
'80 Rolls-Royce Silver Wraith II  Sold
'81 Rolls-Royce Camargue  Sold
'88 Rolls-Royce Corniche II
'89 Rolls-Royce Silver Spur
2020 Ford Escape

Brad Ipsen CLC #737

If you are considering the 3.77 gears into the 38 that is a very difficult thing to do.  The splines on the axles are different.  Also the 3.92 is almost the same as a 41 with a 3.77.  In 41 the wheels are 15".  If you go through the calculations they end up almost the same rpm's on the engine.  Now with the 16" wheels and the 3.77 the engine would be a little slower.  At speed the wind noise exceeds the engine noise and if you consider that in a tank these things ran at full throttle a lot of the time you don't really have to worry about the engine.
Brad Ipsen
1940 Cadillac 60S
1938 Cadillac 9039
1940 Cadillac 6267
1940 LaSalle 5227
1949 Cadillac 6237X
1940 Cadillac 60S Limo

Ohjai

Thanks Brad, I am not going to change anything, just want to do some testing.  I just purchased an APP that requires gear ratios, tire sizes, number of cylinders etc. 


My new (to me) 38 60 Special is know to have a vibration problem and is difficult to start.  The car is still in the New Orleans area and will be delivered to St. Louis Sunday evening.  Next week I will begin my ritual of changing oil, coolant, transmission and differential fluids, and a general going over.


Then I will attempt to solve the hard starting issue, then the vibration issue.  I know the tires are over 15 years old, they will have to be replaced, also have to get it to an inspection station to validate the vehicle ID so I can get it titled in MO.  I already have a 1938 license plate.


The software APP I have is NVH Vibration Analyzer,  from


  https://vibratesoftware.com/vehicle-database/ 


I can hardly wait to start getting my finger nails dirty from this car that is one year older than me.


Jim
'38 Cadillac Series 60 S
'41 Cadillac Series 60 S
2017 Cadillac CT6
'62 Buick Skyhawk Conv
'49 Bentley MK-VI  Sold
'53 Bentley R-Type  Sold
'66 Ford Thunderbird
'64 Rolls-Royce Silver Cloud III
'75 Rolls-Royce Silver Shad Sold
'78 Rolls-Royce Silver Shad II
'80 Rolls-Royce Silver Wraith II  Sold
'81 Rolls-Royce Camargue  Sold
'88 Rolls-Royce Corniche II
'89 Rolls-Royce Silver Spur
2020 Ford Escape

Jay Friedman

#5
There is an exception to the usual gear ratios.  There was an optional special transmission available on Series 75 from 1938 through 1940 and on all 1941 and 1942 cars.  The special transmission has lower ratios of about 2.97 in 1st gear and 1.90 to 1 in 2nd gear.  I got this info from my parts manual.
1949 Cadillac 6107 Club Coupe
1932 Ford V8 Phaeton (restored, not a rod).  Sold
Decatur, Georgia
CLC # 3210, since 1984
"If it won't work, get a bigger hammer."