Mystery Sway Solved ...

[Cowracer]

Originally Posted by TitanMike

Just a side note, lots of trucks are properly fitted with P metric tires. They are usually XL rated so instead of the usual 35# inflation pressure they are rated for a higher cold inflation pressure, usually 41# although the tires on my truck are marked 44#. These tires are reinforced to hold the extra pressure. The extra pressure doesn't increase the load rating, just reduces sidewall flex which reduces sway. The trucks the tires are used on often have axles rated for less than the pair of tires are designed to carry.

Just because it's a truck doesn't mean LT tires are required.

A lot of truck are fitted with P-tires because they never haul a damn thing. They are used as 4-door sedans with an 8 foot trunk and the soccer moms don't like the harshness of the LT ride.

Tim

[aeblank]

Originally Posted by Cowracer

don't like the harshness of the LT ride.

My 2500 with load range Es in a /70 at 75psi.....yeah, a bit bone-jarring at times on crappy MI roads.

[strgrazr]

My new Ram 1500 w/ tow rating of 8900# came with crap Goodyear car tires from factory- great ride empty- the worst sway/bounce I've ever had while towing 29ft 7900# TT. I have great Reese WDH w/ cam sway control that has been on the same trailer- just new truck. I thought it was the Ram coil springs until a piece of gravel cut though the factory tire with only 3200 miles on tires--junk. Replaced all 4 tires with Michelin X LT's, same size, E load rating, max press 80 psi. Inflated to 60 front and 65 rear using load/psi chart. Now it tows like a dream and MPG when up while empty and towing. Every day street driving 50 front and 55 rear for better ride and wear. We put over 7000 miles on new tires towing this year. LT tires made a huge difference for smooth towing, tire sag and SAFETY while towing for us. Tires can't increase the TV GVWR or tow ratings but can make it realistically capable.

[JohnCTB]

Greetings, I’m new here and have learned a lot already. Have had our Avenger 21TH for a year now. Last winter was our first long trip. From Michigan to Texas and back. I made a rookie error and assumed the dealer set my Equalizer hitch up correctly. Not so, I had more sway than I thought I should. Upon further inspection, all the bolts were tight but none of them were torqued to the proper spec. The sockets for the spring arms are supposed to be greased and torqued to 60 ft lbs. mine had little grease and were tightened to about 30 ft lbs. After greasing and tightening everything on the hitch to the proper specs, the trailer handles WAY better! The moral of the story is (and one thing I’ve learned from this site) don’t trust the dealer, check everything. Also, whoever posted that when you buy an RV you are buying a “kit” that is 80% complete and it is up to you to complete the other 20% is absolutely correct!
John

[phillyg]

Originally Posted by MOODMAN

So, I am curious. How does tire size affect sway? I don't see the connection...

I would guess the undersized tire was so different that is was not up to trailering needs. For example, using a P-metric on a truck needing a LR-E tire, resulting in tire squirm.