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Hi everyone, I am building my 1955 F100 to be mostly stock. I am using a T98 4 speed transmission from a 1959 F350. The transmission is the same as the F100 transmission, but it has the transmission mounted parking brake. I also have a stock rear end. My problem is, I have a driveshaft that I was told was from a 1955 F100 with a 4 speed manual but it doesn't reach from the tailshaft to the rear axel. The driveshaft with the slip yoke completely extended is 62" from outside of yoke to outside of yoke. The distance from the tailshaft to rear axle (measured from outside of where yoke goes on both ends) is 62-1/8". That means it is 1/8" too short to even fit when fully extended, which of course still wouldn't work due to suspension travel. So in reality I need an extra inch on the driveshaft.
Does it sound like my driveshaft is too short or does it sound like something else is off? All measurements were done with the weight on the suspension. I also measured from outside yoke to outside yoke, which is probably the incorrect way to measure, but it's easier than measuring center to center. Thanks for all the help in advance!
We talked about all this before, and I still think you have a lot of stuff that's not original. Logically, an F100 driveshaft, all things equal, should be longer than your space if the trans is the same but has the added length of the parking brake on the back of the trans. Would the stock F100 trans use a slip yoke in the end, or does it have a bolt on yoke with a slip joint in the driveshaft? I'm thinking it's the former, which means the driveshaft you were told is a F100 is not.
Personally, imho, if you are going to use the trans now in place, and the rear end that's now in place, I'd have a driveshaft made to fit and call it a day.
We talked about all this before, and I still think you have a lot of stuff that's not original. Logically, an F100 driveshaft, all things equal, should be longer than your space if the trans is the same but has the added length of the parking brake on the back of the trans. Would the stock F100 trans use a slip yoke in the end, or does it have a bolt on yoke with a slip joint in the driveshaft? I'm thinking it's the former, which means the driveshaft you were told is a F100 is not.
Personally, imho, if you are going to use the trans now in place, and the rear end that's now in place, I'd have a driveshaft made to fit and call it a day.
From my understanding, all 4 speed transmissions in these trucks had a transmission flange with the slip yoke built into the driveshaft. It appears that the transmission flange is close to the same distance from the transmission with or without the transmission parking brake. Also, someone else said they swapped in a F350 transmission with the parking brake and original driveshaft and it worked. Everything appears to be original to this generation of truck so I think it should work. I'm just hoping I overlooked something obvious. I contacted a driveshaft shop and they said it would be $300+ to get it lengthened the inch or two.
Can you get us a picture of the other end of the driveshaft? It might help us visualize what you have.
The rear end does look to be a stock dana 44 for 53-56
Here are some more pictures. As you can see the universal joint bearings are not fully seated in the mount, even when the driveshaft is fully extended. Those pictures are of each of the ends.
I think you both are right. It's definitely been modified. Anyone have a stock driveshaft with a slip yoke near the Cincinnati area? If not, I'll shop around and see if I can find a shop to lengthen it for less than my previous quote of $300. Thanks for the help.
I've seen you mention lengthening a driveshaft a couple of times now, and it sounds like you may not be aware of the work involved. It's easy to shorten one as all you need to do is cut one end, clean up the yoke and weld it back together. To make one longer is a different proposition all together, in both time and materials. You don't just "add a couple inches", you have to cut both ends off your existing shaft, clean and prep them, (when I say clean and prep, I mean grind off all the goober weld, fit them into the tube and make ready to weld again. If you've ever done any kind of fabricating, you should understand what that takes. If you haven't, it's tedious and time consuming) and weld both ends onto a new tube. Then it gets balanced. There is significant time and materials involved. I just didn't want you to have the wrong idea of what's involved, or why the cost is what it is. It may not be out of line at all.
I've seen you mention lengthening a driveshaft a couple of times now, and it sounds like you may not be aware of the work involved. It's easy to shorten one as all you need to do is cut one end, clean up the yoke and weld it back together. To make one longer is a different proposition all together, in both time and materials. You don't just "add a couple inches", you have to cut both ends off your existing shaft, clean and prep them, (when I say clean and prep, I mean grind off all the goober weld, fit them into the tube and make ready to weld again. If you've ever done any kind of fabricating, you should understand what that takes. If you haven't, it's tedious and time consuming) and weld both ends onto a new tube. Then it gets balanced. There is significant time and materials involved. I just didn't want you to have the wrong idea of what's involved, or why the cost is what it is. It may not be out of line at all.
I did not mean for it to sound like it is an easy job. I've never lengthened a driveshaft so I didn't realize the effort involved. It's just unfortunate someone previously shortened it because otherwise I'm sure it would have worked. Thank you again for the help figuring this out.
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