drivers side ttb beam rotating upwards during braking

[compleckz]

its crazy, its been doing it for awhile, i just recently had my girlfriend drive the truck around a parking lot and brake fast, so i could see what was up... the left beam rotates upwards, clunks then u let off the brake and it comes down.. its hard to get under there while the truck is being driven obviously, so i cant figure it out.

the truck has a SJ class 2 system, brand new axle pivot bushings, balljoints, tie rods, wheelbearings, u-joints, spindle bearings, the front driveshaft is nicely lubed and slides smoothly.. the left caliper is a rebuild i bought a year ago... the radius arm bushings are the red poly ones from the sj kit, and are maybe 2 years old now, i just had them off a few months ago and they looked fine, minor wear..

i dont recall it doing this before the lift, but it didnt start immediately after lifting either.

anyone familiar with this?

 

[Todd]

The rad arm mounts on the beam are loose. Mine did this before. Get them as tight as you can meaning a large cheater bar.

 

[compleckz]

excellent, i'll go check/tighten them, thanks todd

 

[compleckz]

well after i pulled off the caliper and the coil, i was dissappointed to find the rad arm mounts were solid.. but i decided the forces were greater than i could exert with my jack and a bar... so i took them off anyways.. it wasnt quite a PITA as when i lifted the truck, but it still took quite a bit of persuasion..

i cleaned the bolts up on a wire wheel, cleaned the holes, applied loc-tite, shot them in with the impact.. then grabbed my 1-1/8" wrench (about 18" long), then i put a 3 foot pipe over that, and tightened them till the pipe started to split (and my back)... i was still skeptical, but low and behold, test drove it a few miles on the road, and all is solid.

thanks a bunch todd, i would have NEVER thought that was the problem, they were VERY tight before, but i guess not tight enough...

 

[Jspafford]

Could have been they were corroded enough that even though they "tightened" up it was not actually holding tight.

 

[compleckz]

yea, probably, i'm just so happy its fixed.. i also removed the heater control valve.. i was so sick of the plastic POS.. i've replaced it 3 times.. they always start to leak again out the screw hole or the pushrod... i cut some pipe, and clamped it in.. should be fine for the winter, maybe during the summer i'll put a U-pipe in to keep the cab temps down...