Suspension Issue?

[bama5er]

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?

[Durb]

azdryheat wrote:
Don't blame POS Chinese tires on the suspension. Get a quality, non-Chinese tire (LT tire preferably) and your tire problems will disappear.

LT tires don't come in 235/80R16 if that is what the OP has. If he replaced with LT235/85R16 his problem will be worse as he will now have a half inch of clearance instead of an inch.

There are shackle/equalizer upgrade kits that as a side benefit raise your trailer 1 1/2" to 2". Research Lippert Correct Track II alignment system.

[bama5er]

Giving it a try:









Shazam!

[BarneyS]

bama5er wrote:
Snip... I have some pictures I could post if I could figure out how to post them. Any help?

It is very easy to post pictures on our forums. One of our moderators, 1492, developed this app to post your pictures. It works for other internet sites also. There is no need to have a separate hosting site for your pictures in order to use it.

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Barney

[bama5er]

Sorry for just now responding. Took the RV in today. They said 2 to 4 weeks because they have 90 units in for service. I'll post when I hear from them.

1. While at the dealer I checked the same brand RV's they had. None were below 4" and some were 6" spacing.

2. The majority of the weight as I can see is on the driver side. That's where the kitchen is. The passenger side just has 2 recliners and the dining room table with 4 chairs.

3. As far as any suspension parts being worn out, the first blow-out happened in about 1 year.

4. The tire size of the "F" rated tires is the same as the original. The sidewall height is 80. I had wanted "H" rated tires but after putting one on there was less clearance. The "H" had a sidewall height of 85. If they had put the second "H" tire on that would have been another problem. With the original size (80) there is only 2" clearance between the tires.

5. I typically run about 65mph. The "E" tire were reted at 65mph. The "F" tires are rated at 75mph. So at least I have a 10mph buffer and weight buffer.

Hope that answers the questions/suggestions for now. One somewhat embarrassing issue. I have some pictures I could post if I could figure out how to post them. Any help?

Thanks for all the help so far. I'll keep posting as I have more info.

[JBarca]

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

[fj12ryder]

I have a request for the OP: Please post back on what you've found has caused your problem. Many people neglect that part of the exchange of ideas/information. It would be greatly appreciated. TIA.

[Lynnmor]

1 inch clearance is not enough and any dealer telling you that is correct needs to be out of business. Some suppliers say a minimum of 3 inches. Find your spring and click on "more information" to get the measurements. Springs

It is possible that the trailer was never designed correctly in the first place.

[Grit_dog]

Tread separation and blowing the skin off a tire is likely not due to the tire rubbing occasionally over bumps. I've wore holes through a plywood trailer floor and didn't lose any tires. I've had multiple tires, 5 or 6 in 3 sets that would peel like an orange and they lived a shelters life in the garage under my boat.....all Goodyear Marathins.
Just fixed a trailer this am that one of the crews was hauling a mini exc around on that was so tongue high that the back tandems were rubbing on the frame. It's pretty common.
Buy some good tires and you'll be good. Suspension issue depends on how much/ hard they're hitting the trailer. I'd want to get that thing jacked up a bit or buy some smaller tires if you can.

[SweetLou]

fj12ryder wrote:
Well, if you have evidence of the tire hitting, then I would agree that you have a clearance issue. Whether it's a suspension issue or the result of larger tires that have been installed, perhaps when you went to an "F" rated tire, remains to be seen.

It could be that the springs are not strong enough to support the weight of the trailer. Are they flat, or are they very nicely arched? Some of the builders are notorious for putting just enough suspension to get the trailer to the dealer. You may need to upgrade your springs.

X2 I would look into adding another leaf or changing them out. Dealer should be awarded the bill though

[transamz9]

azdryheat wrote:
Don't blame POS Chinese tires on the suspension. Get a quality, non-Chinese tire (LT tire preferably) and your tire problems will disappear.

Lt tires don't have the capacity a lot of times. I know they don't for my trailer. If the OP's tires are hitting the trailer then he has a problem.

[LIKE2BUILD]

Pictures would really help here.

It's possible the springs are too weak. You might also need install longer spring hangers to give you greater clearance.

Are your axles on top or under the springs? If they are on top maybe it was a goof when assembling the frame or trailer and they're supposed to be on the bottom?

[time2roll]

I bet the springs are shot. Post a picture but I bet they are close to flat vs a nice arc to them. I think I gained 3" maybe 4" when I replaced mine. Although it does seem odd in just four years.

[azdryheat]

Don't blame POS Chinese tires on the suspension. Get a quality, non-Chinese tire (LT tire preferably) and your tire problems will disappear.

[newman_fulltime]

does the unit have taller tires on it than it is set up for?

[fj12ryder]

Well, if you have evidence of the tire hitting, then I would agree that you have a clearance issue. Whether it's a suspension issue or the result of larger tires that have been installed, perhaps when you went to an "F" rated tire, remains to be seen.

It could be that the springs are not strong enough to support the weight of the trailer. Are they flat, or are they very nicely arched? Some of the builders are notorious for putting just enough suspension to get the trailer to the dealer. You may need to upgrade your springs.