19.5 Problems. Please help.

[jblmotorco]

I just spent a ton of money on putting 19.5 wheels and tires on my 2007.5 GMC crewcab dually 4x4. The wheels are Eagle Alloy 056 and the tires are Hercules H-902 225/70/19.5 with a 14 ply rating. My problem is that when I am driving I can turn the steering to swerve and it feels like the rear of the truck is sliding around. It almost feels like driving on ice and sliding a little. The max air pressure on the tires is 110 lbs. and I am running 100 lbs. of air pressure. On the tire it also says mount on 6.75" rim and my rims are 6" rims. I do not think it would affect but I do not know. I am confused on this problem and any thoughts would be greatly appreciated. Thank you.

[mijdirtyjeep]

WOW 100psi!! Try taking it down a little, that truck must ride like a tank.

[jblmotorco]

The ride is really not too bad but the sway that I am complaining about really sucks.

[Medic949]

Take the pressure down to about 65PSI unless towing.

[jblmotorco]

I also do alot of towing. I pull a two car gooseneck trailer alot. What would be a good air pressure to run towing or not so I won't have to be adjusting it all the time? Is the a happy medium?

[Tow Master]

Welcome to the forum!

Ha! Your not crazy! My tow trucks do the same thing with 19.5's when the tires are new. They got to wear in a little. I put recaps on mine and there pretty bad the first 1-2000 miles. Your truck is light so they will take a little while to wear in. If you tow a good sized load for a few hundred miles it will wear quicker. Also, once you get them worn in dont rotate them or Id think it will get worse.

Mine would feel like your gonna spin out doing 70 down the high way. They'll get better after some miles.

[FlintMax]

used to ride in a F-450 work truck, when we went up in tire size from a 225 to a 245 it swayed like that. almost uncontrollably. try a smaller tire if it doesn't fix itself in a few thousand miles. hope this helps