hey.. guys i need some help.I had a 3 on tree tranny i replaced it with a 4 on the floor tranny .I was told the tranny was out of a 1950 truck iam thinking the the tranny is out of 3/4 ton or 1 ton iam not sure.The splines r a lot larger than my 3 on the tree u join splines.The u joint doesnt fit the rear of the drive shaft rod.MY spline on my drive shaft is 1 in 17 splines the u joint that came with the tranny is 1 in 3/8 whith 10 splines .I cant find a u joint that will fit that .........any body know what i can do.......help
Let me start with a question... Does your transmission have the housing to accept the torque ball? If so, it is from either a 1/2 or 3/4 ton. Transmissions from 1 ton and up have a yoke similar to modern vehicles with an open driveshaft. Even though the 1/2 and 3/4 ton trucks use the same transmission, they both use different u-joints. The 3/4 ton u-joint trunion is pressed into the yokes and retained with wire retainers. The u-joint slips on the output shaft as a whole. The 1/2 ton u-joint is different. The 1/2 ton trunion presses into the rear yoke, but bolts into the front yoke. What it boils down to is the fact that there is a specific front yoke for 1/2 ton applications. I learned this the hard way. I also learned that these 1/2 ton 4 speed u-joint parts come up for auction on e-bay from time to time. Hope this helps...
1952 chevy truck u joint Yes.....it does have the torgue tube set up.and it also had a speedo gear on it.thanx 4 your help.
1952 chevy truck u joint Also .....like u said yes the u joint is pressed in.any other suggestion.This is my first project .so iam a rookie at this but I have learned a lot all ready.thanx....again if u have any more help I will take it. Thanx
U-Joint Fun As replacment parts , both typs of U-Joints are made with differing spline counts so just use that as a guide . The same Muncie SM420 tranny was used in 1/2 T up to the biggest trucks , this is why there's more than one spline count but as long as you match up the spline count , you're good to go . Cheapest way is to find a takeout from a Hot Rod project , there's plenty out there . Joe in Az. will have what you need , go look in the classified section .
The speedo drive gear from the 3 speed transmission will not work with the 4 speed. They are completely different. Basically, the back half of your 3 speed u-joint (the rear yoke that slips onto the driveshaft and the trunion) will work. The front yoke is specific to the 1/2 ton 4 speed. This, along with the 4 speed 1/2 ton speedo drive gear, is the piece you will need to find.
Mr. Clean, Have you resolved your u-joint issue yet? I am having exactley the same problem you are. I am converting the original 3-on the tree to the old M420 4-speed. The tranny is 10 spline and the driveline 17 spline. If you have figured this out, or found a u-joint/yoke set up that works, let me know. Thanks
Where did you tell him to find the parts? Looked for Jo in the classifieds and could not find. Do you have contact information for Joe?
Mother Trucker Parts Just click on his name above his avatar on the left there , then select private message... He finds them by looking in his private stash .
