Increasing Axle Spacing on Tandem Axle Trailer to Use Larger Tires

Updated 10/06/2015 | Published 10/04/2015

Products Featured in This Question

6-Leaf Double-Eye Spring for 7,000-lb Trailer Axles - 24-7/8" Long

(2044)

$75.74

5-Leaf Double-Eye Spring for 6,000-lb Trailer Axles - 25-1/4" Long

(2045)

$73.50

Provider ST235/80R16 Radial Trailer Tire - Load Range E

(1094)

$190.67

Question:

On my fifth wheel trailer I have tandem 6,000 lb Dexter axles with 33inch spacing. With the stock 235/80R16 tires I have about 2inch between the tires. I would like to go to G-rated 235/85R16 tires but the increased diameter will leave me with just 1inch of spacing. Will putting 7,000 lb, e64SR leaf springs, which are 3/8inch shorter than the 6,000 lb, SP-111275s be safe to use with the stock Dexter E-Z Flex equalizer, part number 13-143? I have the 13-143s installed now. Will installing those new leaf springs gain me a little bit of extra clearance? I am not looking to upgrade the tires to carry extra weight, just to gain the safety of a much better tire. The trailer is not loaded to be in excess of the axle capacity. Thank you.

asked by: Sean B

Expert Reply:

The minimum distance between front and rear tires on a tandem axle trailer is 1 inch (when under load). If you are at 1 inch now and the trailer is not loaded then you would need to move at least one axle. This means that you would have to cut off hangers and have them welded back on in a new location by a professional welder.

Spring # e34SR is indeed longer than # e64SR by 3/8 of an inch. If you went with shorter springs and longer equalizers then you could get more space between the axles. However, the trailer was built with the axles in those locations to best distribute the weight. Changing that could void any warranty and can change how the trailer rides.

You can upgrade tires and still stick within the same size, 235/80-16, using # TTWTRTM2358016E. This tire is a 10 ply rating and capacity of 3,520 pounds at 80 psi. Using 4 of these tires would provide a capacity of 14,080 which is more than enough for the axle capacities.

expert reply by: Michael H