OPPS and a driveshaft ?

79f-250custom · #1 (**permalink**) 07-17-2008, 09:14 PM

haha, broke a U-joint in the high boy today. while i was taking off the driveshaft i noticed the guy had the front and back driveshaft were flipfloped. i didnt even notice this while i had the tranny out. so i was wondering if the guy had a reason for doing this. i gave him a ringer and he said that it had somthing to do with the rear axle???? here are some pics. both front and rear axles are 8 lugs. d-44 frong and a dana 70 rear i think?
here are some pics.
any one know any reason for doing this or did he not know he did this?
thanks
Mitch

ech0sh4y · #2 (**permalink**) 07-17-2008, 10:17 PM

haha carnage!! wooo kinda sounds goofy to me.. maybe something with the u-joint size for the yoke on the rear axle?

79f-250custom · #3 (**permalink**) 07-17-2008, 10:55 PM

thats fuel for tinken. ill have to check on that.
thanks
Mitch

75F350 · #4 (**permalink**) 07-18-2008, 03:09 AM

I do not see a double cardon joint there, so it really should not matter which direction the shaft is installed.
However, I do see a problem with the length of the front shaft. I see that the front joint sheered at a point, or in a manner that is not typical. As a can see from the pic, I see that the front shaft has very little room to compress. From the dark area on the very base of the slines, it would appear that the shaft bottomed out. It looks like the shaft is too long, and the shaft does not have enough room to compress. When it bottomed out, it had no place to go, and it killed the joint.
I could be wrong, but it appears that this shaft is not correct, and your problem will occur again.
Normal suspension cycles will eat up at least that much driveshaft travel.
FWIW, all of my HB's had (stock) double cardan joints for both front and rear shafts.

NumberDummy · #5 (**permalink**) 07-18-2008, 03:44 AM

As original:

1975 F250 4WD 133" Wheelbase (High Boy).

Front driveshaft length: 20 1/32" from center of eyelet to end.