2009 Yukon Denali - launching boat sliding tires

[Zed 71]

I'm thinking at this point that it's not really a GM issue, but an issue of the weight distribution of the boat. I think what you are describing could happen to any towing vehicle if enough weight is on the tongue.

Generally speaking, trailers/boats should be setup so that only 500 pounds or so should rest on the tongue/hitch. If the weight of the boat is moved too far forward of the trailer's center of gravity, the problem you are having will undoubtedly occur.

What kind of boat are you towing and what kind of trailer are you using. If using a V nose trailer, it may be possible to adjust where the V sits on the trailer, thus moving the boat backward.

Also, you mentioned that you had to use a different ball. Is this because the boat forced the rear end of the truck down too far? If so, there is probably way too much weight on your hitch, both for ramp launches and towing in general. If you have a heavy duty scale, try to weight the tongue weight of the trailer where it rests on the hitch. I believe the max is 500 pounds give or take. If you only have a 300 pound scale, I believe you can set a block on the scale and another block a few feet away, then put a strong board across both blocks and set the tongue on the middle of the board. The scale should read roughly half of the weight of the tongue. Of course, you will need to know the weight of the blocks and board (times 1/2) to accurately read the weight.

Let me know if this doesn't make any sense, and I can try to explain better. Check this out for a diagram and some instructions on how to weigh a heavier tongue:

http://www.etrailer.com/faq-trailertowtips.aspx

^ Bingo! It's all about proper tongue weight like I mentioned in my first post.

BTW nice boats everyone has!

 

[BlizzardX23]

Sorry, but you're totally wrong. Yes, a 2wd should be able to launch a boat too, but in this case, if the truck was actually a 4X4 with the transfer case in high or low lock position, there would be no slip or spinning of the front tires. It's not complicated, it's as you say, the center of gravity and the lack of weight on the front axle. If the truck was "locked up", then all the tires would have to slide, not just the fronts. If the ramp is that steep and/or slippery, then what is happening is that the front axle is becoming so unloaded that the front brakes are locking and allowing the front tires to slide while the rears are still rolling. That would not happen in a 4X4. His only option is to increase traction on the front axle by putting on better tires, and/or lowering tire pressure, or adding weight to the front by either actually adding weight or changing to a weight distributing hitch. I'm not 100% familiar with the AWD in a Denali, but I don't think you lose AWD in reverse. It is NOT a good idea to leave the truck in drive and allow the truck to be pulled backwards at the same time.

I understand your logic, and its true. However, the point is, in a situation where the boat is hooked up correctly, and the weight distribution is correct, it wont matter if its AWD or 4x4. My Pop uses MANUAL(none of that push button ********) 4x4 in his F150 to launch the boat, I use my AWD Denali to launch it.....I have done it the fastest, smoothest, and safest in my AWD...Does that mean that 4x4 is better? NO....does that mean AWD is better? no...


and x2 on the red section...that is not a good idea....


and yes, I leave my truck in reverse during the entire process of launching....until its time to pull forward and go park

 

[SmallXL]

It's a weight distribution issue.

Upward of 70%+ of the braking bias is typically at the front. When unloaded on a wet/slick surface it's easy to lock them up and slide the front while the rear isn't locked. It can be unnerving, but you're not going to end up in the water (never mind, never say "never", lol).

Personally, I use Neutral when backing up b/c I don't need any help with 15,000# of gravity moving in that direction. At the river house there is a steep driveway, the topside when I pull in for the day is gravel then there is a transition to cement leading to the garages. Anyhow, I'll partially keep the e-brake locked to slow the decent so the front tires don't lock up and pull gravel over when moving onto cement... keeps more bias to the rear.

I believe it's a 2 or 3" drop hitch (although, it should be more). The correct height may help, but you could just have heavy tongue weight.

Dropping tire pressure in the front will help. If you ever get stuck dropping psi is usually your best bet.