Steering Adjustment

on my 2007 yz450f there is noticable back and forth rocking of the forks when performing the steering check as indicated in the service manual. The steering is not loose, that is no rocking side to side. The issue issue is the that the manual indicates you need to adjust the steering head....but then doesn't explain what adjustment to make....only thing that makes sense to me is to tighten the nut that holds the steering bering/shaft onto the frame....a few people posted on this previously but they were lost in the upgrade. All suggestions welcome....also the yama parts website doesn't list the lower bearing as a part that can be purchased..if it comes to that.

Yamaha sells the upper and lower bearings individually. The lower is item 50 on the Front Fork page, and the upper is item 1 on the Steering page.

PN's are 93332-00081-00 and 93332-00078-00.

If you loosen the top clamp at the crown nut and upper pinch bolts, you can tighten the ring nut over the bearings a bit with a punch. Recheck the preload after torquing the crown nut.

If it's been a while, you should open the bearings and clean/inspect/relube them.

Yamaha sells the upper and lower bearings individually. The lower is item 50 on the Front Fork page, and the upper is item 1 on the Steering page.

PN's are 93332-00081-00 and 93332-00078-00.

If you loosen the top clamp at the crown nut and upper pinch bolts, you can tighten the ring nut over the bearings a bit with a punch. Recheck the preload after torquing the crown nut.

If it's been a while, you should open the bearings and clean/inspect/relube them.

Hey thanks for the info... i took off the bars and top clamp to get to the ring nut and sure enough the guy i bought it from must of forgottent to put the plan washer back on top of the ring nut. (he had installed a stabilizer at some time...) so when i got to the ring nut it was so loose you could tighten it by hand. That picked up all the rock...problem is that when I place the clamps back on and torque the nut down it pulls up on the steering column making the steering bind up. (i'm guessing they had the same problem but didn't realize they were missing the washer).

... so when i got to the ring nut it was so loose you could tighten it by hand. ...problem is that when I place the clamps back on and torque the nut down it pulls up on the steering column making the steering bind up.

That's normal. When you tighten the ring nut, there's an outward pull on the threads and stem, and the threads have at least a working clearance between them. But when the crown nut is torqued as high as it is, the force of that pushes the ring nut downward by the amount of clearance in the threads, pushing the bearings closer together, and loading them tighter then you had them set.

The manual procedure is to tighten the ring to 5 ft/lb and then reassemble the top clamp. It works better if you tighten the ring to about 20 ft/lb, rotate the steering column several times, and then back the nut off to zero, and retorque to 5 ft/lb. The 5 ft/lb value is what varies, and it ends up being something that is much easier done by feel; if where you had it was too tight, loosen it a little and see what it's like after you run the crown nut down. Adjust it as necessary.

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