Question about 4wd system and launching a boat.

[Shadow17]

I was asking a question regarding launching a boat by myself in the Chaparral forum and some concerns I had with the truck being 'unmanned' while loading/unloading.

I like to have someone in the truck with their foot on the brake pedal to keep the brakes applied on both front and rear wheels. Most of the time I have the rear wheels in the water in order to launch my boat. And there is usually a nice slick coating of slime right around the water level on the loading ramp.

Some guys stated if I placed the truck in 4wd HI or LO, transmission in park, and set my parking brake(rear brakes only), it would lock the front and rear axles together providing the same traction as having one's foot on the brake pedal. Granted the parking brake needs to be in good, firm condition.

Does this sound about right with our 4WD systems, or do the Yukons have something that would cause this not to happen?

 

[drakon543]

Im still new to gm suv/trucks but that is how most 4x4 trucks and suvs work. Once you have engaged the 4wd it stays locked until you disengage it. If the rear is locked even if the rear wants to slide the front wont.

 

[Yukon John]

I have been doing this a while and have learned quite a bit over the decades. First of all..NEVER trust the Park pin to hold your truck/trailer on the ramp (or anywhere else for that matter). If you look at the mechanism in a typical automatic transmission you will be surprised that it's about 1/3 the thickness of a pencil !! I have seen 4 Truck/Boat combos launched using Park only to hold a rig!!I always let the weight of my rig rest first against the parking brake and then put it in Park as a "back up".

I carry 2: Rubber Wedges that are used for chocking aircraft wheels at airports. They are available at Northern Tool for about $30.

I connected 6' of "Swing set" chain to each one and hook them to the hitch safety chain loops with a spring clip, then place one chock behind each wheel after I position the rig for launching. When I launch the boat or retrieve the boat, I pull to the top of the ramp and disconnect the chains...stowing them in the cargo area. The chains are just long enough to drag behind the truck and not get tangled in the trailer. Doing this will prevent your Truck/Trailer from rolling backwards. If you arrangement requires you to have your rear wheels in the water you can still chock the front wheels, find something along the frame to hook your chains to and pull the chocks with you up the ramp.

I have used 4WD on steep ramps at low tide and it helps...as long as you use 4 High. If you use 4 Low you will probably sit and spin. My current 2WD Posi Yukon pulls well up most ramps but occasionally I have put the Transmission in M and start in 2nd gear....this is sort of like using the torque converter to "slip the clutch" and I get little or no spin.

I have used this method for over 30 years here in South Florida where we deal with variable tides, slick ramps at low tide and different angles or approach based on location.

Hope this gives you guys some ideas.

 

[Kpwweb]

I was asking a question regarding launching a boat by myself in the Chaparral forum and some concerns I had with the truck being 'unmanned' while loading/unloading.

I like to have someone in the truck with their foot on the brake pedal to keep the brakes applied on both front and rear wheels. Most of the time I have the rear wheels in the water in order to launch my boat. And there is usually a nice slick coating of slime right around the water level on the loading ramp.

Some guys stated if I placed the truck in 4wd HI or LO, transmission in park, and set my parking brake(rear brakes only), it would lock the front and rear axles together providing the same traction as having one's foot on the brake pedal. Granted the parking brake needs to be in good, firm condition.

Does this sound about right with our 4WD systems, or do the Yukons have something that would cause this not to happen?

4 HI or 4LO will lock the front and rear wheels together. AWD or AUTO will not (the middle transfer case diff is in play then).