rear pulls to right when braking??

[Datafive0]

I just rebuilt the MC and under heavy breaking the whole bike walks right on the rear. Front is tracking like normal. Any ideas?

[Dogma]

Any chance you're leaning on the handlebars when braking? Maybe leaning on the right hand more than the left?

[jwhelan65]

Your rear wheel is not aligned

[koolaid_kid]

Your rear wheel is not aligned

Absolutely. This is a dangerous situation and you should correct it immediately.

[Datafive0]

That is what I was thinking..

[Curly]

That's happened to me when the axle isn't tight. Accelerating jerks it to the left, braking to the right, rocking it back and forth in the adjustment range.

Ignore the FSM torque rating. Tighten the rear axle until your arms fall off. If you're not worried about snapping the axle, you haven't tightened it enough.

[Flyboy]

+1 on the loose axle, also check swingarm bearings and tightness, as well as rear wheel bearings, any play in either of them will cause the back wheel to move from side to side.

[Datafive0]

Okay, got some time tonight to look over the rear wheel situation. I checked the wheel alignment using a caliper. Hit the rear wheel with a wrench and it was lose(ish) torqued to factory spec. So I took it apart, checked everything and greased everything up, wrenched on it until I could not turn anymore! Checked movement of wheel on stand, it rolls freely. I do think that the chain is needing to be changed in the distance future. Weather was too nasty to check it, but I will follow up with my findings.

[TheCafeKid]

Double check also that you put all your axle spacers back, in correct order. Even an extra 1/8inch of spacer missing will not leave enough thread to torque the axel bolt tight enough to squish the swingarm against the caliper hanger and bearings.
If you're working with a stock set up, on the rotor side generally you'll have the top hat spacer/bearing shield, the caliper hanger and usually another spacer between the hanger and the swingarm. Some models don't have that outboard spacer however, so if you're not sure, check a parts diagram. Also assure that you have your washer behind your castle nut (axle nut).