Thor Forums

[jwcorry]

The problem: When we top off water, propane and fuel tanks along with the usual stuff one carries in a 29' MH plus me and DW, we are significantly over the manufacturer's GVWR of 16,000# (although not over the individual front and rear GAWRs).

The details: MH is a 2014 Thor ACE 29.2 mounted on a 190 inch wheelbase Ford F53 chassis. I noted subsequent versions of the ACE 29.# are on the 18,000# GVWR chassis. Soooo, I compared the 190 in. wheelbase F53 16K specs with those of the 190 in. wheelbase 18K for the 2014 model year.

The findings: Both have the same Max GCVWR, and all specs related to the power-train, frame, brakes, steering, wheels, tires and suspension related parts (axles, stabilizer bars and shocks) are identical for the two versions. The only difference is the deflection rates of the springs, although both versions are single-stage, constant rate with the same number of leaves and the same dimensions. One is 550 lbs./in./spring and the other is 650 lbs/in./spring for the fronts, and 950 lbs./in./spring and 1120 lbs./in./spring for the rears. There are absolutely no other differences in the two chassis's I can find.

My solution: I realize no one can alter the GVWR a manufacturer assigns to a chassis. However, realistically, if the only difference is the deflection rate of the two sets of springs, I rationalized I can, in fact, increase my payload (by ~800 - 900#) by installing helper springs (SuperSprings in the rear and SumoSprings on the front to mitigate the deflection rate difference since that is what helper type springs are designed for (stabilizing and reducing squat).

The question: Are there any flaws in my thinking on this matter (besides any legalistic issue)?