The transmission in my 32 Chevy roadster has the following part numbers (on the top) 590591 with the number 7 below and on the side of the transmission housing is 590695 with GM-6 under the numbers Can someone tell me the year etc of the transmission? Thanks
The 590591 is the correct part for the 1932 passenger transmission. Not sure on the other number but 32 and 33 were the only years that had the "freewheeling" feature. My later parts book shows the top cover as 363840 for all 32-36 syncho-mesh transmissions.
There are two 1932 transmissions. The early one with "Spur" (straight) cut gears and the later with "Helical" (angle) cut gears. The '33-'36 transmissions look the same but have differences inside.
The spur gears in the 1932 was for all the gears and the angle cut gears for 2nd speed only. This made for what Chevrolet called the slinent 2nd gear. While it was not completely silent it was a lot quieter than with the straight gears wich sounded like 1st gear (gear whine).
Only 1932 All and 1933 Master has free wheeling.
You can up date the spur gear unit by replacing the cluster and 2nd spd gears.
My 33 has the free wheeling, like a 32. I don't know if there is a difference between 32 and 33. Pretty sure that is the only 2 years that had free wheeling.
The freewheeling unit was bolted on. The 1/2 ton trucks used the same transmission in 1932 and 1933 but without the freewheeling unit. The torque tube on the rear end was therefore longer.
My 32 roadster does NOT have the free wheeling unit which I must assume is not the original transmission. Does anyone have any information on the side number 590695 with the GM 7 stamping. Could any of these numbers correspond to a 1936 transmission? Prior to the restoration of this car in 1992 the engine installed was manufactured in February 12 1936 (B-12-36) During the restoration a correct date coded engine was installed with a date of November 30 1931 (K-30-31) I read somewhere the GM stamping did not appear on the transmission housing until 1934, is this info correct?
I am guessing that it is a 35 or 36 . As Chipper noted the torque tube is longer if no free wheeling unit is attached so when the 36 engine was installed I am guessing they also installed the trans and rear axle. I can not find the 590695 casting number to a part number listing but the part number listed in my catalogs is 590697and usually the part number is close to the casting number.. There is a listing on Ebay for a case with the 590695 casting number and is listed as 35-36. Hopefully someone has a casting number to part number for proper documentation.
On the 1936 case the speedomter gears were above the center line of the case and 1934 and 1935 below. It waa moved up higher in 1936 to reduce gear oil leakage at that point. After that time if you purchased a new case for a 11934-35 case you got the "improved" 1936 case.
