67 F-150 manual 2x4 converted to 4x4 6 inch lift by someone else. I bought it recently for $800. and was told it is a steal, the problem is the driveline falls off due to the U Bolts breaking right after installing them. The side that breaks is where is connects to the rear axel, not at the tranny. I was told that is because the driveline is at to steep of an angle. If so how do I fix? I have been just to drive it in 2 wheel and do not hook up the rear driveline. Will that damage anything?
Thanks,
Chantz

 

You can drive it with only the front end connected. It won't destroy it, but I wouldn't try to haul anything with it or push it very hard. The front end was never designed to carry the full load of the vehicle on it's own. It is only designed to suppliment the rear end, so get it fixed as soon as practicable.

To fix your driveline problem, the truck needs to go to a reputable welder who can cut-off and realign the leaf-spring perches. Ideally the angles of the two u-joints should be identical. This will balance the harmonics caused by the driveshaft as it spins. If the angle is too steep you may encounter binding, which can grenade the joints as yours is doing. As a last resort, you can get a driveshaft with double-cardan type joints which split the angle between two joints within about 4 inches. The Bronco IIs came with this type of arrangement at the transmission end of the shaft.

Seriously, I would talk to a tech at a rear-end specialist like Curry Enterprises or a driveshaft specialist like Dick's driveshafts. They'll be able to give you better info based on measurements from your truck. Dick's Driveshafts built me a new 1-piece shaft for my first Ranger from measurements they had me take. It fit perfect the first time and as far as I know it's still running great now.

 

Thank you, I appreciate your help.
Chantz
Kallie's son

 

here's a site about high angle drivelines: http://www.drivetrain.com/driveline_angle_problem.html

 

One other thing that will cause this is your slip joint being out of time.
A problem that is amplified by extreme angles.Just a thought.

Pat

 

Your breakage could also be caused by axle torque when you accelerate. Also have the driveshaft length meassured and make sure it ain't too long for it's application.