Is this a tekonsha P3?

If so, there is a lever on the bottom of the controller. The brake controller senses deceleration and then feeds by impedance to the electric brakes.

What you need to do is apply the brakes manually using the lever (the more you pull it towards you the harder it will apply the trailer brakes) before you start to lock up the tow vehicle. You may have to brake most of the way down the ramp if it's that steep. Even so, manually applying the brakes SHOULD stop your vehicle sliding EXCEPT that gravity is not working in your favor in this situation. If you apply the trailer brakes before you start sliding you should not end up in a bad way.

That said does the truck have no problem pulling the boat out? If so, traction and drive are not your issue and it's an issue of the trailer dragging you backward, so you need to brake it with the controller before its speed becomes enough force to overcome your braking.

What do you have for brakes on the truck? Factory?

For reference, towing a 4500lb horse trailer with horses up, I have my P3 set at 5.5.

 

For reference, towing a 4500lb horse trailer with horses up, I have my P3 set at 5.5.

So that's about 6000lb GTW for reference.

 

No, I don't think you have an issue. The brake setting is immaterial because the system does not apply brake in reverse to the degree you're going to need. The system works based on the inertia of the vehicle's motion. In this case, because you are going backwards down a hill, it can't determine how much brake force to apply.

My P3 controller has a reverse mode. I believe the P2 does as well. This video will show you how to engage it.

Without reverse mode, you effectively do not have trailer brakes in reverse.

 

Thank you. I will try the reverse mode next time I launch the boat. Actually, I didn't think reverse mode applied the brakes in reverse, but it appears that it simply takes away the Boost and not the breaking application...from what you are telling me. I would rather not have to engage the brakes manually while backing a trailer down a boat ramp. I have enough on my mind. Especially with the steepness of this ramp, and the number of people walking around it. I hope the reverse mode in the P2 and P3 do the same thing. Also, if they do, I would have bought the P3 had I known... Live and learn!

 

I'm not really expert in this stuff, but knowing how brake controllers work I think there is no way to avoid manual application..

The key, at any rate, is to keep momentum under control.. and make sure you don't have too much tongue weight..

You're not alone, 2009 Yukon Denali - launching boat sliding tires | Page 3 | Chevy Tahoe Forum | GMC Yukon Forum | Tahoe Z71 | Cadillac Escalade - Tahoe Yukon Forum is a thread about the same thing happening with a Yukon.. it's just physics..

 

some generic info at Electric Over Hydraulic Brakes - Trailering - BoatUS Magazine .. note the tow vehicle in the lead pic

 

DBN, what tires are you running and what kind of shape are they in?

My boat/trailer are around 4,500 lbs. I launched at multiple ramps once I got my D at the end of August, never locked or skidded. I never had the issue with my Tahoe either.

 

They are new Bridgestone Ecopia tires...came on my 2017 DD.

 

I'm thinking I would measure the tongue weight of the trailer too.

 

I think I'm going to do that. I will have to buy a scale from etrailer.

 

I think the ramp is the problem, maybe look for a better one and save yourself some headache... haha

Seriously though, I can relate. The rivers we fish in my area have some easy in and out style ramps, and then some that are nearly straight up and down. As luck would have it some of the better areas we fish are near the worst ramps depending on the time of year, water levels, etc. We have seen some funny stuff on those ramps, as well as having a few stories of my own. Oh well its the price we pay to do what we love.

Honestly though its hard to beat a 4wd, 4 door truck for loading/unloading a boat. Its always better to have more than you need. It sounds like the Durango is plenty capable til it hits the steep ramp, simply because you have reached the limits of what it can do safely, and everything else is just masking the real problem. Find a better ramp!!,lol

 

I know the ramp is one of the problems. However it's a private yacht club and we are members. I really never had trouble with locking the front end with my 2010 Chevy four door four wheel drive truck. ..except when I would back down a little too quickly. All this tells me that the tongue weight on the trailer is probably too high. I wonder how I could fix that? The trailer really can't be adjusted since the trailer is designed for only one boat...on my Cobalt 226. No adjustments, everything is welded in place.

 

We had too little TW on my parents boat, and we moved the axle back one set of bolt holes. Shorelander trailer. If you are say there is no adjustment, can you move the boat back on the trailer or is that front winch mount welded as well?

 

The front winch Mount is welded. But maybe I can have Magnum trailers cut it and move it back. I will see if I have a pic.

 

It looks like you are using a 2" drop ball mount. Try a 4" drop and see if it helps at all.

 

have someone sit in the very back of the boat and see what happens.

 

Like maybe a couple of the Cowboys offensive linemen.

 

UPDATE: Back to square one. I took the trailer back to Magnum Trailers. Tongue weight is roughly 550 lbs. No issue there...but we did find that the brakes they installed were not even working...even though the brake controller reacted as if they were. The Brake-rite pump would never even switch on, until the brake controller was maxed out to level 14...locking up the wheels! Let's see if they can figure it out...I imagine once the brakes are working properly, the front end drag when launching the boat will be eliminated. It's just amazing the shop did not figure it out the first time.

 

550lb? do you have a WDH? (I forgot, it's been a long thread)

 

There is not one that fits my trailer per etrailer...at least one with trunion bars. Maybe one with chains. But I hear you cannot backup on tight ramps with a weight distribution hitch that has chains...requiring me to take off part of the hitch before I launch the boat every time I launch it...which I would like to avoid.

 

I know that's about 10% of trailer weight, but I feel you'd be fine with 300 lbs. and that is quite likely contributing to your problem.

 

Yeah, 7-10% with a boat trailer.
I think you're on the high side at 550 lbs.

Tongue Weight DIY - Trailering Guide - BoatUS Magazine

 

550 on the tongue without a WDH is Not A Good Thing in that situation.

 

As Tom said, there's a bit more to the story than just the %. A WDH can take care of a lot of issues. On an SUV like the Durango the suspension isn't designed to deal all that well with that kind of tongue weight without a WDH. On a 3/4 ton pickup it would be a non issue either way, but the tail is wagging the dog in this case. I'm fine with dropping to 5% tongue weight.

 

Not needed with that size boat.
I tow a larger size Cobalt with no issues with only 2wd and I've launched at several ramps including a very steep ramp without issue with my '14 Hemi and my old '01 4.7L D. Same boat.
Its in his trailer set-up.

 

Cobalt 226 is 3800 lbs dry...so 380 lbs tongue weight is what you should be shooting for...certainly no more than 400 lbs.
You are 150 lbs heavy IMO.
Also I noted your trailer tongue is very short, maybe simple extending that will take care of things.
Compare to this picture.

OLYMPUS DIGITAL CAMERA ? Cobalt Boat Owners Club

 

That makes a lot of sense. I will keep that in mind if the electronic over hydraulic brakes don't resolve the issue.

 

Right, that's what we're all saying, it's in his trailer setup. If he can't change the configuration of the trailer and stays with the 550 lb. tongue weight, he needs a WDH. If he can lower tongue weight, he should be fine without one.

You're taking 10% of the dry weight of the boat. What about the trailer, aren't you ignoring the trailer weight? That double axle should weigh 1,200 lbs. or so.

 

Oops, missed DBN's posts. Backs up what I was trying to say.

 

So regardless, is it the general consensus that if I extend the tounge thereby lowering the tongue weight, I avoid the need or a weight distribution hitch. That way, with the electronic over hydraulic brakes and the extended tongue I have a safe rig?

 

I don't believe adding a foot to the tongue length would make enough difference. What is really needed is to shift the boat back on the trailer, or the axles forward, same result. I don't know how easy/hard either is to achieve without seeing the trailer, but have a feeling neither is simple.

Before you do anything, let's see what happens when they get the trailer brakes fixed. If it stops skidding, and tows OK, then no need to do anything else.

 

Thanks GreenD. The shop will be able to move the boat back a few inches. However, the boat is currently already back 2.5 inches because I did not put the bow all the way up against the trailer stop. So I don't know how much all that will help. However I will keep everything in mind. And if that's the case I'm not opposed to doing it. You would think that the trailer shop would know all of this. Fix it right the first time. Thanks for all the input!

 

So digging around a bit online I found one trailer site that recommends you only need 5% of total weight on tongue towing a boat with a dual axle trailer.
That puts it at 272 lbs.
7% would be 380 lbs.

So I think I'm pretty spot on with my 300-350lb tongue weight target.

 

UPDATE: The shop got the brakes working properly. Air in the pump, and a brown wire that needed to be left unconnected, something to do with batteries and breakaway issues. They want me to pick it up, and try it out, without reducing the tongue weight at this juncture since the self-leveling shocks take care of evening out the vehicle when towing the boat. In other words, see how it handles. I will "update" again after I pick it up and tow it to the lake.

 

since the self-leveling shocks take care of evening out the vehicle when towing the boat.

Actually, not.. but we'll get to that discussion later

 

That's great that they figured it out!

The brown wire might be a charging wire for a system that has a battery on the trailer. Or at least that's my guess.

 

The brown wire needed to be disconnected from the breakaway switch, it is only used under circumstances, but I can't remember their explanation now...

UPDATE: Suffice it to say now the pump is working properly and the brakes on the trailer really make a world of difference in controlling the trailer. I did not notice any issues with a light front end, and the trailer pulled smoothly from the shop to my house which included neighborhood and highway driving...about 6 miles. I will know more when I launch the boat for the first time with everything working. I noticed that the max break reading from the brake controller, which I set just to before lock up occurred, is about 8.5. Happy so far...

 

8.5 sounds much better.

The breakaway system has a battery inside it (to apply the brakes on a breakaway); my guess is that wire is for charging the battery.

 

Because there is still not going to be a lot of deceleration going on, you may still have to touch the manual brake some..
But at least the manual brake will work now, with the air out of the system..

edit: if you can, you are best to leave your controller set for normal driving, and use other features to deal with special situations. Dialing the controller up to 14 and forgetting that you did that will make for a fun ride home

 

Because there is still not going to be a lot of deceleration going on, you may still have to touch the manual brake some..
But at least the manual brake will work now, with the air out of the system..

The shop told me to set the brake controller at maximum when backing down the ramp. They did not say to manually engage it. Guess I will find out