I've got a 618T and when this boat is loaded on the trailer it always want to go way on the left side of the bow roller. I've even switched the bunks around the other night and then loaded it up deeper than normal. Went right to the middle of the bow roller. Thought the problem was fixed. Got home and boat has "walked" back to the left of the roller. Not a huge problem but it is putting scratches in the bow where it comes in contact with the front roller gaurd. Suggestions???

Since the boat "walked" off the roller while trailering ... I would take a hard look at how you are securing the bow into winch tower.

Somehow there is slack in the way you are securing the boat to the trailer. It sounds to me like the bow is not secure. I hope you are using a safety chain and not just a winch strap and transom tie downs.

Is your trailer close to level when your hooked up to your tow vehicle?


Morton

Sounds like the boards are at a slight angle to the center line of the trailer.

you may want to change your bow roller. The picture on the left is one I found of a 618T, the one on the right is a "V" shaped roller that has flared sides, to help guide the bow in. Also, You may want to add a bow strap, that runs vertically from the eye down to the trailer tongue, to keep the bow from bouncing.
HRG

Some thing you might consider is how steep your boat launch is as well. I have a Ranger as well and I have access to two boat launches in the lake I usually fish. I usually have this same side load problem - the bottom of the hull that is supposed to fit between the trailer bunks at the very bottom slightly rides up at the back of my starboard side bunk...maybe one inch at worst. I usually have to backer back in to just about floating and give er a push over.

The other launch is a steeper angle and I get her on first time perfect every time. I don't if this is your problem as well but it may be worth considering.

Regards,
Kroe