|
|
|
|
Joined: Aug 2013
Posts: 99
Shade Tree Mechanic
|
OP
Shade Tree Mechanic
Joined: Aug 2013
Posts: 99 |
I am trying to assist another gentleman get his '37 1/2 ton back on the road. The transmission that was pulled out of the truck has casting number 590874 on it. A 3 speed car transmission in a truck?
I took one of my spare 4 speeds to the shop working on his truck and they are claiming that they can't get the transmission into the truck. Something about the input shaft being different.
Is there anyone more familiar with the car running gear that can help us sort out what we need to do to put a 4 speed back into this truck?
Does anyone have a 3 speed they are looking to part with?
Thanks for the help,
|
|
|
|
|
Joined: Aug 2013
Posts: 99
Shade Tree Mechanic
|
|
OP
Shade Tree Mechanic
Joined: Aug 2013
Posts: 99 |
I have learned something new. Apparently, that casting number is not for a car but actually for the truck. Can someone confirm this for me?
What is casting 590874 used for?
Thanks,
|
|
|
|
|
Joined: Jan 2002
Posts: 2,299 Likes: 8
ChatMaster - 2,000
|
|
ChatMaster - 2,000
Joined: Jan 2002
Posts: 2,299 Likes: 8 |
Yes that is correct for 1937-39 trucks.
|
|
|
|
|
Joined: Aug 2013
Posts: 99
Shade Tree Mechanic
|
|
OP
Shade Tree Mechanic
Joined: Aug 2013
Posts: 99 |
Thank you,
Is it possible to put in a 4 speed (from the same era) where a three speed once was?
Justin
|
|
|
|
|
Joined: Jan 2002
Posts: 30,701 Likes: 141
ChatMaster - 25,000
|
|
ChatMaster - 25,000
Joined: Jan 2002
Posts: 30,701 Likes: 141 |
The 3 and 4 speed truck transmissions have a different bolt patterns going onto the bellhousing. A car 3 speed will not bolt up to a truck bellhousing
Gene Schneider
|
|
|
|
|
Joined: Aug 2013
Posts: 99
Shade Tree Mechanic
|
|
OP
Shade Tree Mechanic
Joined: Aug 2013
Posts: 99 |
Gene, According to the '37 Service Manual the 3 speed truck and 4 speed truck transmission were interchangeable except for the speedo gear. https://drive.google.com/open?id=0BwpjuqQnrSned2Z0bjdCX3RNTzgAm I reading this incorrectly? Justin
Last edited by 37ChevTruck; 09/13/16 04:00 PM. Reason: spelling
|
|
|
|
|
Joined: Jan 2002
Posts: 30,701 Likes: 141
ChatMaster - 25,000
|
|
ChatMaster - 25,000
Joined: Jan 2002
Posts: 30,701 Likes: 141 |
Gene Schneider
|
|
|
|
|
Joined: Aug 2013
Posts: 99
Shade Tree Mechanic
|
|
OP
Shade Tree Mechanic
Joined: Aug 2013
Posts: 99 |
|
|
|
|
|
Joined: Jan 2002
Posts: 30,701 Likes: 141
ChatMaster - 25,000
|
|
ChatMaster - 25,000
Joined: Jan 2002
Posts: 30,701 Likes: 141 |
Sorry, thought it said correctly. The truck 3 speed and 4 speed are interchanable. Car 3 speed is not.
When the truck 3 speed in used to replace a truck 4 speed the 4 speed spedometer gears are different from the 3 speed as is the mount bracket.
Gene Schneider
|
|
|
|
|
Joined: May 2002
Posts: 6,149 Likes: 42
ChatMaster - 6,000
|
|
ChatMaster - 6,000
Joined: May 2002
Posts: 6,149 Likes: 42 |
I have the 3 speed originally out of my 1/2 ton and the 4 speed out of a 39 1/2 ton and I noticed the slip joint/universal joint are different. 1 has a bush at the very front of the drive tube supporting the rear section of the universal joint and another more rearward supporting the driveshaft while the other gearbox the front bush is more rearward and runs on the driveshaft only. I must admit the 4 speed had a heavier differential behind it so that may have made some difference. Both boxes appear to be the same length and I think the same universal ball but I havent looked at speedo drive.
Tony
1938 1/2 ton Hope to drive it before I retire
|
|
|
|
|
|
|
