Sydwayz

iTrader: (1)

After you specifically posted that; it sounds the setup is your problem. Let's see a picture of the entire boat/trailer. Compare it to other 353s on other trailers in classified adds; specifically where is the front step in relation to the front axle on the trailer. This will give you an indication of COG; and if it's placed well or not.

What is your tongue weight?
What is your overall complete boat/trailer/fuel/gear etc. towed load weight?

Also, have you installed Airbags on the truck? Does it squat when loaded?
Measure your front wheel track width and the same for the rear. Are they the same? Some of the GM platforms have a 3.5" wider front axle than the rear.

Boats are not the easiest thing to setup on a trailer to tow. You have a LOT of weight at the tail end, which can wind up as tail wagging the dog; which sounds like your issue here.

Formula353

The truck does have air bags
The truck does squat a little not much I will post a picture or I can email it. Total weight loaded is 13900
I got around 1300 on the tounge weight
I can feel the rear end of the truck feels loose also I need to upgrade to EOH from surge that may make a difference as the boat likes to push the truck while going around curves and braking.
Also the front track of the truck is wider

obnoxus

What tires do you have,,,, when I towed my 36 Outlaw ( 12,600 ) with my 2500 I had Michelins on it,,,, I swapped to Yokohamas and a little taller when it needed rubber and it was a white knuckle nightmare,,,,they cam off in a week and back to Michelins , The stock 245/85-16s were not bad but you still have to " drive " the truck where as DRW is mindlessly rolling down the road.

I would play with moving the boat forward or back to see where stability improves.

EOH would be a great addition as well as you are approaching the limits of the truck,,,,,,,,,,,, but surge aren't horrible if they are working properly,,,, do you have brakes on 2 or all 3 axles,,,, and are the disk or drum???

Sydwayz

iTrader: (1)

I figured it was over 13K lbs. It sounds like you have a steel trailer, correct?
EoH is worth every last red cent. Go ahead and do that; and get it out of the way.
Then, buy some of the solid wheel spacers for the rear, so it matches the front track.
Something like this:
http://www.ebay.com/itm/2-Chevrolet-...03ed8e&vxp=mtr
(They come in different thicknesses. I last bought a set like this in 2002; from a company that is no longer in business. You MUST buy a quality product here, not something cheap and dirty. You have hub centric vs. lug centric to consider. Best to consult an expert here.)
Are you still running the 20" wheels? Are the correctly weight capacity rated? Are you also running E-rated tires, air up to max (or close to) PSI?

The factory 6.5" wide GM HD wheels absolutely SUCK for towing stability; especially on that narrow rear track.

Also, are you still running the factory hitch? It is rated for the 13,900 lbs as weight carrying? The GM factory hitch is known as the "flexi-flyer" due to how flimsy it is.
Once you go to an EoH, you could easily add a full WD hitch setup to your trailer, including sway control. You CANNOT do that with the surge brake setup.
(Surge brake setups and WD hitches can work, but typically not with sway control. The Equalizer Hitch is an exception. Regardless, do the EoH conversion as it's the best money you will spend here.)

Formula353

I am not running the 20s now I gave them back to my buddy they were E rated tires I have the stock wheels on it now with toyo at2 in 265/75 they suck I did change the hitch to a draw tite ultra frame I just need to get it right cause towing in the mountains or hills near lake Cumberland really sucks

Brain check ur email
Also I am on a steel trailer
So adding the spacer to the rear and going to a 20in wheel will correct some of the issue?

obnoxus

The theory is more wheel, less tire sidewall will cut down sway

Sydwayz

iTrader: (1)

No email. Please check spelling of my first name. (I appreciate the compliment in your post above. Someone else recently posted that I must be a know it all. )

I am quite certain you will see a drastic improvement with:
EoH brakes
Spacers
More rubber on the road (bigger contact patch)

I agree with Den/obnoxus... to a point.
You absolutely need to ditch the OEM wheels/tires. I'd look into a 18" diameter and 8 or 9" wide wheel, on a quality E-load rated tire, and make sure the wheels are weight rated as well.
AND, get that rear track spaced out to match the front.

I've posted many times about the GM wheel spacers and going to wider wheels/tire on the SRW platform. You can find more info with a search here on OSO. There are many threads on tow vehicle tires. Yokohama and Michelin always float to the top though. Personally, I am a big fan of Cooper tires as well.

http://mrtruck.net/spacer.htm
http://www.offshoreonly.com/forums/t...els-truck.html
http://www.offshoreonly.com/forums/f...rd-hauler.html
http://www.offshoreonly.com/forums/g...tch-balls.html

I had 16x8 wheels on my 2500 Avalanche back in the day on D-rated tires. I was towing ~12,000 lbs. of Active Thunder/trailer/gear. (My previous boat was smaller, and I went from the factory E-rated setup to D-rated tires.)
For 1 weekend trip I went back to the factory 16x6.5" wheels and factory tires 245-16-something or another.
IT WAS THE WORST TOW I'VE EVER HAD. I only went that one weekend because I had ordered 17x8" wheels/E-range tires; and they had not arrived yet.

I can definitively say in back to back to back towing with 3 wheel/tire packages on the same truck (similar to yours) that the bigger wheels/wider (E-rated) tires is drastically better than the factory setup.

Turbojack

I will argue that point.

Depends on what year 2500HD and what year F250 On a 2005 2500HD to a 2011 F250, both diesel, there is no comparison. Once you tow with the Ford, it will make you trade in the Chev for a Ford. I know, been there, done that. The problem with the 2500HD is the 2005 model. Mine would overheat all the time when towing. Took it to the dealer and they said everything was normal. Did a search on the internet and there were tons of problem with that year overheating. The 2006 model they had fixed the problems of overheating. The 2001 2500HD I had before that was a great truck for towing.

hogie roll

I know for some period of the time the only difference between 2500 and 3500 was srw and drw. Everything else was identical.

Danno302

iTrader: (1)

FWIW, I followed Brian's advice on another forum for my 2004 Chevy Avalanche 2500 (didn't realize "Sydwayz" was the same guy until now)....installed Firestone air bags, wheel spacers, 410 gears, and upgraded to 285-17 Terra Grapplers. I'm towing 35' steel trailer ~ 10,5k with ease EXCEPT... The last piece of my puzzle is in progress- EOH disc brake conversion! The original surge drum brakes helped with straight line stopping ONLY, but, now that I'm in mountainous terrain with long steep boat ramps they will no longer suffice. I'm also running a 160* thermostat with a tune on the 8.1. There are better tow vehicles for sure but I'm very confident in this setup and love the Avy 2500 when not towing. These guys know their shtuff!!!