bama5er wrote:
I have a 2013 Sierra 38' fifth wheel. I have lost 3 tires due to complete tread separation in 4 years. I thought originally that I had a load rating (E) tire problem. However, after replacing all 5 tires with a F load rated tire I looked closer at the suspension. It seems I only have about an inch clearance from the top of the tire to the RV chassis.
This seems very close. I have ALKO axles with Lippert Equi-Flex. My dealer says this is normal for my suspension. The issue is there is evidence (hole) where the tires have hit the bottom of the chassis. I would say this means that 1 inch is not enough clearance. If the tire running at 60-65 MPH hits a stationary object (RV chassis) that would cause the tread separation and a rough ride.
Question: Is there a standard minimum clearance for this?
Hi,
You may have a few problems. To the easier question, 1" fender clearance is not normal and in the case of a TT or 5'er, this seems down right wrong. Your suspension cannot work correctly with that little a travel.
Dexter recommends 3" as a general rule. My TT manufacture set mine up on 2.5" and it works but much less then 2" and sooner or later your gonna hit. You can test this if you want to set it up.
Tire failures, there is a lot to this. Have you weighed the camper by each wheel location? Suggest this as a start. Odds are high all 4 wheels are not loaded even. Ideally you have 20% extra tire load capacity over the heaviest loaded wheel. Does that exist as you have it? What is the axle/spring rating of the camper? (GAWR) Are you at or under that rating?
Are they ST tires with a speed rating of 65mph and do you stay under that limit?
Tire pressure, what are you running on the E load range when they failed?
Can you share the brand?
As the others have said, going to F load range, did it change the OD of the tire?
What is the spacing between the 2 tires as measured horizontally? Meaning the 3:00 position on one tire to the 9:00 position on the other tire.
On the Equa-flex, look at the rubber in in-between the 2 plates, is the rubber heavily cracked? If the rubber is shot it will lower the camper.
The comment about the dealer and 1" bump clearance being normal. His statement does not add up on any trailer with leaf springs. Look in his yard and ask him to find you other new campers with 1" bump clearance. If he actually has one, find the model/make and year.
Hope this helps and yes, please report back on the findings.
John