I have a 1994 F-150, 8ft bed, 2wd, 302, 4r70w, reg. cab truck with stock everything.

Recently I hit a wooden one-lane bridge a little quick (25mph) and went airborne about 9" or so, but did not seem to bottom out. It was kind of cool at the time, but it threw my alignment out. It could have been that, or one of the massive potholes I hit that afternoon too. But the bed was empty and we didn't have any weight in it (even the tailgate was off).

Anyway, I took the truck to get aligned and it needed the bushings kit and a new left lower ball joint. I had them installed, and it's aligned to the middle of factor specs for the front for toe, camber, and castor. The alignment numbers are the best i've seen in my life.

It still pulls terribly to the left though. I took it back it, and everything seems right on. Me and the tech are stumped. The rear is pointing 0.23 to the right, and we think this might be part of the reason for the pull.

Any other ideas of what this might be? Or what to check? The pull to the left is pretty noticeable, and needs about a 1/8 - 1/16 of the wheel turn to the right to maintain going straight.

Is it tough to perform a rear wheel alignment? The tech suggested using a come-along and to apply tension to the rear axle, then loosen the spring shackle bolts until it pops to the left, then tighten the bolts backup.

I am also going to check bearings and brakes, but I don't think this is part of the reason because the pull is more or less constant, not higher when breaking. If anything, it is more pronounced during acceleration.


Also, when cornering in my neighborhood the rear will make two clicking/popping noises, once from the left, and once from the right around each corner.
I would appreciate any suggestions, besides not driving like the dukes of hazzard over bridges.

Any ideas to get this thing straight?

 

Does it really pull, or is the steering wheel just off center? When you set the steering wheel a little to the left (to make it go straight) and let go of the wheel, does the truck go relatively straight? If so then the steering wheel is off center, which could be caused by the rear thrust angle. I would leave the rear axle alone and just adjust the toe so the steer ahead angle is straight. The toe won't be in the middle of factory specs but as long as its within the range that the repair manual or alignment machine gives you it won't wear tires. It will make the truck dogtrack down the road but you won't be able to tell when your driving.

If you have to hold pressure on the wheel to the left to make if go straight then that is a pull. If it is a pull, and it was caused by you going airborne then there is probably a bent suspension part, in which case you need to look at more than just the basic camber, caster, and toe. How does the turning angle, steering axis inclination, included angle, and steering offset look? Pretty much all modern computerized alignment machine will measure these angles, the tech will just have click a few buttons to make the machine display them.

-Jon

 

Just out of curiosity, have you tried rotating the tires, and seeing if the problem is unchanged?

 

That's a good point, lots of pulling/drifting problems are actually caused by tire conicity. Swap the two front tires and see if it straightens out or drifts the other way.

-Jon