Bronco Clunk? When Taking off...

[Ripcity]

I have a 70 Bronco and sometimes when I take off I hear a clunk. Sounds like it is coming from the rear end. Upon inspection everything looks ok and I have had someone drive it while I looked under the rig. Any ideas what it could be? The rear end has been serviced and given a clean bill of health as well as the drive line u-joints.

Thanks
Tim in Oregon

 

[oleguy74]

check slip joint,u-joints both ends of drive shaft.block wheels ,leave i neautral and wiggle drive shaft.watch u-joints and pinion for slack .just a place to start

 

[Viperwolf1]

Slip joint.

 

[scotts77]

I had a now and then clunk a while back. Turned out to be a rear axle bearing. More likely the slip joint, but don't rule out other things back there.

 

[73AnneBoleyn]

axle wrap.

http://www.wildhorses4x4.com/category/rear_suspension_parts

HTH;D

 

[a67and77]

I had a clunk in my 77 and turned out to be loose and bad t-case mounts. My next guess would be loose u-bolts.

 

[Amac70]

ill guess axle wrap and loose u bolts also, possibly even sheared centering pin.

 

[biglor96]

I am having the same kind of issue with my 76, it is not so much of a single clunk but more there is somthing popping but as you take off and it goes away as i gain speed. I have checked everything underneath and i can not find anything. what could this be.. axle wrap, u bolts, u joints?????

 

[biglor96]

stupis question, what is a slip joint????

 

[Broncobowsher]

Loose spare tire? That was mine once. Bastard to find. Pull away gently and all was fine. A little more aggressive and I would get a delayed clunk as the spare settled back into place. Only happened from a stop. Caught it out the corner of the mirror one day as I saw the tire move in rythem to the clunk. Then I could repeat it and watch it. Clunk and tire movment related.

Second would be a binding slip joint on the rear driveshaft. May be smooth by hand but may bind when torque is applied

 

[biglor96]

no spare on my ride....

 

[Broncobowsher]

stupis question, what is a slip joint????

Slip joint is the part between the U-joints that lets the shaft get longer and shorter as drivetrain and suspension parts move around.