BobB Posted September 29, 2018 Report Posted September 29, 2018 Looking to strengthen the transmission in a 47 WD21 to make a heavy hauler. would a C-39883/C-39011 transmission from the same year be likely to fit? Is there documentation somewhere that I can use to evaluate options that I find? thanks, Bob Quote
Jomani Posted September 30, 2018 Report Posted September 30, 2018 Sorry, I can’t answer your question. As the owner of a 47 WD-21 myself, I am just curious - are you looking for something that will tow better? Synchronized? I have never driven my truck so I don’t know what the what the ratio is for each gear. The original transmission seemed to be very stout but suffered from serious water damage. The replacement four speed that I got is supposed to be synchronized - at least third and fourth. Unfortunately, I couldn’t tell you what it is. Quote
BobB Posted September 30, 2018 Author Report Posted September 30, 2018 I have somewhat of a Frankenstein truck. When if first posted about it, I had a lot of questions and the smart guys on here pointed out features that were unique to 1942 and 1947, so not really certain of its heritage. in particular, it was pointed out that a 1 ton truck should not be sporting a 3 speed transmission. That’s the main reason I’m looking for something stouter. I just haven’t seen conversion charts for transmission swaps like I have for differentials, etc. just wondering what resources are out there. Guess it’s spline counting time... thanks, Bob Quote
Jomani Posted September 30, 2018 Report Posted September 30, 2018 Makes sense. I still have the original four speed out of mine. It is shot, but I can provide pictures, measurements, etc. if that helps. Quote
MBF Posted October 1, 2018 Report Posted October 1, 2018 Both the original 3 & 4 speeds have a 1:1 ratio in the highest gear. You can't just swap in a 4 speed w/o swapping the bell housing-the bolt patterns are different. Quote
Jomani Posted October 4, 2018 Report Posted October 4, 2018 Too bad you are way across the country. Just found out that my engine is junk - very likely that I will not be using the bell housing, flywheel, clutch, and transmission that I just picked up for my WD-21. I plan to pull the top off the trans tomorrow to see what it looks like. Hopefully, it turns out better than the engine. Quote
wayfarer Posted October 8, 2018 Report Posted October 8, 2018 I'd suggest backing up a step or two and determine which bellhousing you have before dealing with the trans. As mentioned, truck trans and car trans usually need different bells. If you buy someting long distance remember that Fastenal ships crates at low cost. 1 Quote
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