Will Incorrect Tire Inflation Pressure Affect Handling from Grand Design Reflection 28BH 5th Wheel

Updated 04/30/2018 | Published 04/27/2018

Question:

I swapped out the OEM tires - Westlake Load Rage E 10 ply 80 psi tires to Sailun Load range G 14 ply 110 psi tires. With the Westlake tires, I really didnt feel much chucking at all with my 2017 F450 pulling a 11k lb GVW Grand Design Reflection 28bh. After the switch to the Sailuns, I noticed significantly more chucking on the freeway. Its not terrible but noticeable. I could only attribute it to the harder riding Sailuns. But they were only aired up to 80 lbs, not the 110 psi its rated for. Do I need to now swap out the OEM Lippert pin box to a different pin box - something like a TrailAir? If so which one?

asked by: Denny

Expert Reply:

If you were running your new special trailer tires a full 30-psi below their rated (and required) 110-psi inflation pressure then that is probably the cause for the degraded handling from your Grand Design Reflection trailer.

Special trailer tires, the ST-type, must ALWAYS be inflated to their maximum COLD psi pressure as noted on the tire sidewall. It is never appropriate to under- or over-inflate a trailer tire for any reason; there is no benefit to doing so and this can cause loss of load capacity and loss of speed capacity.

Trailer tires can deliver their rated weight handling capacity and maximum driving speed only when properly inflated to their maximum cold psi pressure. Incorrect inflation pressure, driving faster than the tire's rated speed and overloading them past their weight limit all cause excessive heat in a tire and this is what typically leads to tire failure.

Once you air the tires to their full rated pressure you should find your handling restored.

expert reply by: Adam R