2009 Yukon Denali - launching boat sliding tires

[fjlarosa59]

Blizzard, I use the same process as you, but I use reverse, which I assume you do also. My setup is simliar to SmallXl's, but my boat is not that big. I have a regular size Yukon, so obviously my wheelbase is less than the XL. I do feel better than somebody else experiences this. I'll try backing down in the neutral.

SmallXL, what do you have a drop down ball? If so, how much? I had to lower mine in order to tow the boat and I still wonder if that's affecting it.

---------- Post added at 08:23 PM ---------- Previous post was at 08:17 PM ----------

Scott, the front tires slide while the back basically roll. I have been able to stop it before it hits the water, but it's very uncomfortable because I lose a little bit of control when I'm steering the vehicle down the ramp. You did trigger a thought. I may call Heritage and see if they have any suggestions. Can't call Baja because they don't exist anymore. I may also call my local dealer to see if they know anything. I do wonder about moving the boat back on the trailer.

All of you guys have been great to reply and it's really appreciated. Typical boat people. Always willing to help.

Other suggestions are appreciated.

---------- Post added at 08:24 PM ---------- Previous post was at 08:23 PM ----------

P.S. GM has been worthless.

 

[ScottL4619]

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

 

[stevek]

P.S. GM has been worthless.

It's not GM's problem. It's simply the laws of physics.

 

[fjlarosa59]

I know it's not their problem, per se, but I called to see if they had any suggestions regarding the laws of physics on a Yukon rated at towing capacity 8,100 that slides down a boat ramp while towing a boat much less than that since it's their vehicle.

 

[ScottL4619]

You need to figure out the max tongue weight for your truck and then determine the tongue weight of your trailer. According to a site I found, with a standard hitch, your tongue weight has to be 500lbs or less and up to 1275lbs with a weight distribution hitch.

This is most likely the issue...

Oh, and I believe the max towing capacity for your truck is only 5,000 pounds with a dead weight hitch...you need a weight distributing hitch to get up to 8100 pounds.

 

[baron]

And tow ratings don't mean a whole hell of a lot... I've pulled 15k loads with a truck rated at 5k, it was just a matter of having the proper trailer, electric brakes, and distributing the weight correctly. Like Scott said, a lot of it has to do with how the load is distributed. I believe you said you have a couple of people in the boat already? One or two people sitting/standing in the bow (or worse, as I have seen some not super bright folks ride on the tongue area as the boat backs down) can greatly effect the amount of tongue weight.

 

[SabrToothSqrl]

well

since everyone else was posting photos of their toys...

 

[fjlarosa59]

Thanks guys. I thought about the weight distribution system also. I just spoke w/ Heritage trailer and the service guy mentioned backing down in drive, which will keep tension on the front drive, especially since it's AWD. I'm going to try that. He also mentioned not moving the tow hitch up, since that's an option. He said they configure the boats and trailers pretty well and that shouldn't be needed. If all else fails, I may go to the WDS.

Frank

 

[Fast55]

That really has nothing to do with it in this situation... I see 2WD trucks back boats in with no issues...my AWD Denali backed the pontoon in with no slipping and it was backed in so deep that the water was to the top of my rear fender lip, above the tires. PLUS, he said its slipping when he has the front brakes on...so AWD/4x4 is completely irrelevant in this case...

Seeing as how a 4X4/AWD setup is not needed to launch boats, I'm seeing this to be more complicated.

If possible, can you post a picture of your setup?

Heres how we launch ours. Tell me how it compares

Im in my truck....my Mom and GF are sitting on the seats in the middle of the boat with my Pop in the driver seat...I back the truck/trailer down the ramp (no slipping) until the boat floats off the trailer which is when my Pop puts the boat into reverse and pulls it away from the ramp. I then put it into drive and pull up the ramp to park the truck/trailer.

Im really wondering about your Center of Gravity....

You say it slides when your truck is in reverse and your backing down...until the point of being in the water and launching. The ramp is wet...are your tires in good condition?

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.

 

[ScottL4619]

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 agree with this, I do not think it's a good idea either. I would tackle the weight issue first.