Boat trailer bunks are the parts of the trailer that support the hull of the boat in transit. If the boat is correctly positioned on the trailer with the majority of the boat’s weight resting on the rollers then adjusting the trailer bunks can be done while the boat is on the trailer in order to make the boat steadier in transit.
Step 1 – Check the Keel Rollers
The boat should be resting on the keel rollers, if after inspecting the trailer you find that this is not the case then adjustments need to be made. So check properly.
Step 2 – Repositioning the Rollers
Starting at the top, use an wrench to loosen the bolts holding the keel roller in place, lift the roller so it is touching the boat and retighten the bolt. Using a torque wrench, you need to torque each bolt to the manufactures specification.
Step 3 – Adjusting the Boat Trailer Bunks
In a similar way as you did with the rollers, unscrew each bolt with the adjustable screw and reposition the trailer bunks so that they touch the boat, taking particular care not to place your finger between the bunk and the boat. Once placed correctly, retighten the screw. When adjusting these bolts you need to work from front to back.
Step 4 – Repetition
This step needs to be repeated every time the boat is taken out. This is to be done as moving the trailer can make the bolts of the boat trailer bunks adjust slightly.