Does anyone know if front wheel spacers will cause increased jerking side to side when launching in 4wd? i have some on the front (1/4").

Short answer: Yes it will make it worse....sorta.

Long answer:

The side to side jerking is caused by your scrub radius.....the scrub radius is the distance from the wheel center line and the pivot point of the spindle. The pivot point of the spindle is found by drawing a line through the upper and lower ball joints to the ground. Most manufacturer's aim for about 1" of scrub, this gives you feed back while turning. Any more than this and the steering wheel will "fight" back when hitting bumps, any less and the steering gets numb and unresponsive. When in 4wd launching, one tire will always spin first, the tire that still has traction then over powers the one that's spinning causing the steering wheel to shoot towards the side that's spinning. Adding to your scrub radius with either aftermarket rims or spacers just gives the tire a longer leaver to jerk the wheel out of your hand. For a pulling or drag truck you would want zero scrub that way when the tire is spinning there is no way the tire can push the steering linkage. So it will make it worse, but it's more the result of loosing traction. If you don't spin the tires it won't do the side to side jigle. Lowering the torsion bars and putting on stickier tires will eliminate the wheel spin.

Short answer: Yes it will make it worse....sorta.

Long answer:

The side to side jerking is caused by your scrub radius.....the scrub radius is the distance from the wheel center line and the pivot point of the spindle. The pivot point of the spindle is found by drawing a line through the upper and lower ball joints to the ground. Most manufacturer's aim for about 1" of scrub, this gives you feed back while turning. Any more than this and the steering wheel will "fight" back when hitting bumps, any less and the steering gets numb and unresponsive. When in 4wd launching, one tire will always spin first, the tire that still has traction then over powers the one that's spinning causing the steering wheel to shoot towards the side that's spinning. Adding to your scrub radius with either aftermarket rims or spacers just gives the tire a longer leaver to jerk the wheel out of your hand. For a pulling or drag truck you would want zero scrub that way when the tire is spinning there is no way the tire can push the steering linkage. So it will make it worse, but it's more the result of loosing traction. If you don't spin the tires it won't do the side to side jigle. Lowering the torsion bars and putting on stickier tires will eliminate the wheel spin.
got it. thanks lmm. might have to take em off :D