Driveshafts

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Nov 9, 2001 | 12:53 AM

edh

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Driveshafts

I have a 66 F-100 longbed that came with a 352 and 3-speed. The previous owner swapped in an automatic with a slip yoke in the tailshaft. It still has the two piece driveshaft with carrier bearing, but the front shaft was cut down and the auto slip yoke was welded in, and it wasn't lined up when they welded it on. So now, I have two slip yokes, one in the rear shaft, and one going into the tranny. Needless to say, it vibrates really bad.
I have a 69 F-250 with the same tranny, and it has the yoke on the tailshaft similar to a rearend yoke with u-joint straps. If I swapped transmissions, would I be able to use the three quarter ton two piece driveshaft? I know I would have to get a u-joint that has the three quarter ton driveshaft size, and the half ton rearend yoke size, but I was wondering if the length would be correct? Thanks for any help or suggestions.

Nov 9, 2001 | 03:17 AM

jowilker

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Driveshafts

Ed, You might want to check with a driveshaft shop. When I swapped in a C6 into my 66, I went to a one piece ds. I had a local ds shop make it up to my dementions and it works great. I suspect that the end on your 250 at the rear is different.
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Nov 9, 2001 | 06:31 AM

William

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From: Sun River St. George

Driveshafts

edh, I'd have the short shaft re built, and I'd have the long shaft checked for true, and balanced. I'd also have a close look at the carrier bearing, that may actually be the source of the vibration. While you're at it have the tires balanced and inspect the rims for true. Add new cross shafts and you're in business.
William in Atlanta

Nov 9, 2001 | 08:41 AM

cobraguy

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From: San Diego CA

Driveshafts

EDH 2piece driveshafts can be a pain. I have a buddy who owns a driveshaft shop, he gave me a driveshaft geometry lesson when I was setting up my truck. His point was that you need to have the front section come as straight as possible off the tranny "like an extension of the tailshaft" then the end angles of the rear section have to be the same. Last the tailshaft and the pinion have be the same distance between frame rails and any variance is remedied by mountig the carrier off center. After all that was said and done I'm looking for a one piece that is 63" center to center on the Ujoints. Good Luck, Rich

Nov 9, 2001 | 12:30 PM

edh

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Driveshafts

Thanks for the input guys. I think I will go with having a shop build a one piece driveshaft.

Nov 10, 2001 | 10:27 PM

packrat_1954

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Driveshafts

Another thing you have to watch for, is to make sure the u-joints are in "plane" when you have a two piece driveshaft. the newer shafts has a blind spline, where you could slip them togather only one way, the older ones would go togather in any spline. You need to make sure the "Y" part of the drive shaft, and the slip yoke that goes on the other end of the same shaft, are in line...if you lay the shaft on a table,with the cup holder, on the shaft itself on the table, the cup holder of the yoke, should be on the table also.

Nov 23, 2001 | 11:03 PM

edh

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Driveshafts

Well, I got my new one piece driveshaft back today. I installed new axle seals, and a pinion seal, and finally I can drive my truck without it shaking my fillings out! I had Performance Drivelines build it for me in Cincinnati. I would highly recommend their work to anyone.
Thanks again for everyone's help!