New adjusters are not broken in. Required break in period is 20 cycles.

Operate the seat to the full-forward position and then to the full-rearward position several times to work new adjuster tightness out of channels.

Adjusters are improperly lubricated.

Use AutoLube A or equivalent to lubricate the adjuster channels.

Adjusters are binding due to bent and/or damaged channels.

Replace the adjusters.

Adjusters are binding due to the bearing being out of position.

Push on each adjuster to full-forward at stops to rephase.