can anyone tell me if a 4 speed tranny out of a 47 /48 one ton closed driveshaft will fit a 1/2 ton up to 53 i believe they went to open shafts in 54 right? you guys are the experts anyway what trucks will this tranny fit thanks for your help robert
If the 53 already had a SM420 4 speed You can simply change out the the closed shaft and open shaft parts if you have both trannies. I found a real low mileage 1T 50 model 4 speed and replaced the the torque tube 4 speed in my 54 with it by switching out the back housings and U joints on the 2 trannies. Otherwise, you will need to find a 1/2 T sm420 48-54 for the closed shaft application, but make sure you get the U joint, these are pricey. Jim
maybe i got it wrong trans was pulled from truck that had a closed driveshaft maybe not a one ton i am trying to find out what it will fit .old truck has 8 hole wheels hood emblems on side say chevrolet 3600 looks like whats left of vin tag on door post was 6800# pounds but the numbers are rough door handles pull down so what year and size do you guys think it is vin started with5gr-h 1097 thats the best i could get can that trans be used in a 1/2 ton are they the same except for changes on driveshaft thanks for your help robert
5GRH1097 translates to a 1949 3/4ton pickup built in August at the Kansas City, Missouri assembly plant. 8 lug wheels and the "3600" hood emblem further prove that it is a 3/4 ton truck.
The 1949 3/4 ton driveline was a 2 piece enclosed/open driveline { enclosed from trans. to carrier bearing & open from carrier bearing to rear end}. This trans will adapt to the 1/2 ton enclosed torque tube.
U joint It will work, but you will need to acquire a 1/2T closed drive U joint. The 3/4T U joint will not work with the 1/2T drive line. Jim
It'll Work Just look closely at the U-Joint splines . (count them) GM used two different U-Joints on the same spline count ~one is light duty ,(3 speed 1/2T) and the other is heavy duty (4 speed apps) . The tranny remains the same as the bigger trucks had a short enclosed forward driveshaft . Now that I've enswered your qustion , may I be so bold as to request the left over speedo drive gear ? (the one on the side of the tranny the cable attaches to) . Maybe the left over U-Joints & yokes etc. too.....
late late reply vwnate1 i am sorry i have not looked at this post since i thanked everyone above your post just seen it i hope you got the parts you needed we are still on hold on that one to many projects but none to get rid of at this time except 72 i am posting ad on again sorry i did not reply to you way back then
