Blow Out Repair - lift, new axles and wheels

[TomHaycraft]

Blow out in November, finally got trailer back last week. Tire failure and circumstances well chronicled in prior Carlisle thread (http://www.keystonerv.org/forums/showthread.php?t=23190&highlight=Carlisle&page=2).

Broke hole in subfloor, damaged wiring, bent spindle/axle. Insurance covered axles, so I took opportunity to increase from 3,500 lb to 4,400 lb axles. This allowed me to go from 5 to 6 lug, so I went from 15" to 16" wheels, mounted up Maxxis M8008s. To add clearance for taller wheels and to level the trailer, added a 3" lift, giving me 4 3/4" in added height. Oh, and to keep belts from busting through subfloor again if I have another blow out, had the shop add .060 steel to tops of wheel wells. New CAT Scale weights in a couple weeks, see how much weight we added to the base of the trailer!

Trailer now rides level, hopefully I have significantly lowered my risk of future blow-outs. Overall height now 12' 9". In the attached photos, nose up reduced slightly after that photo when I dropped hitch to one hole to lowest setting. In "after" photo, it was ever so slightly nose down, corrected by raising hitch one hole. Perfect now! We missed camping in December and January, first months missed in 3 1/2 years. Heading out in 2 weeks for a 3-day weekend, can't wait!

Lift and New Wheels (https://goo.gl/photos/G94RKDBk964F13Ji6)

[TomHaycraft]

One other thing ...

I would be remiss if I didn't give a shout-out to Crestview RV in Georgetown, TX. While I gave their sales department hell in public posts about their insistence on trying to get me into a trailer that would have overloaded my (at the time) 1/2 ton truck. Not only did they lose the sale, but I was so irritated, I happily drove 200 miles to Franklin's RV in Abilene, TX for the Springdale, great little shop.

That being said, the repair side of Crestview RV came through twice for me in the last 6 months. First, replacement of the forward gray tank, now the repairs from the blow out and lift of the trailer. While slow as molasses getting the insurance estimate out, then delayed by Christmas holiday closing at Keystone to ship the axles, the work was impeccable. The engagement of the tech / mechanic was first class, engineering of the subframe with its cross members for lateral support, down to details about how the corplast was secured and sealed, along with the .060 steel in the wheel wells. Thank you Daniel!

[dcg9381]

Tom, that's great. Thanks for the photos of the repairs. Looking at it, I wouldn't know the difference from factory.

Moving that RV up 3-4" - how level does it sit on the 5th wheel when towing?

[TomHaycraft]

Trailer now tows perfectly level, measuring from the frame to ground in front and behind the wheels. We'll have to watch the first step, now 13" off the ground, don't know if I'll replace the fold-out steps with a set of 4, or just bring along a portable step for use when we need it. Likely have about 8" between the bedrails and trailer. She sits tall and proud.

[T3/T4 Hybrid]

Those welds look like an art piece! All of it looks very professionally done. I like how your rig sits level. :cool:

[Jay Pat]

Tom, did Crestview allow you back in the shop?
Thanks, Pat

[TomHaycraft]

Tom, did Crestview allow you back in the shop?
Thanks, Pat

Can I trust you are not a plant for their insurance company? :D

I was invited back once during the decision-making process to confirm the weight of sheet metal to use and methods to secure and waterproof the wheel wells. We also talked about options for engineering the lift and cross-bracing. After that, was a time when I was directed to drive around to the bay the trailer was in when dropping off the new 16" wheels and then to perform a PDI (of sorts) upon acceptance of the completed work.

Why do you ask?

[Jay Pat]

Can I trust you are not a plant for their insurance company? :D

I was invited back once during the decision-making process to confirm the weight of sheet metal to use and methods to secure and waterproof the wheel wells. We also talked about options for engineering the lift and cross-bracing. After that, was a time when I was directed to drive around to the bay the trailer was in when dropping off the new 16" wheels and then to perform a PDI (of sorts) upon acceptance of the completed work.

Why do you ask?

I don't like not being allowed to go back in the shop area to see what's going on. I fully understand the reason to not allow. I just don't like it. So, I was wondering about your access.
I keep my rv at home and use a mobile service (I have full access and can ask all the questions I would like). I do like to try and learn stuff for repairs on the road (when I have to...). I'm talking about the breakdowns on early Sunday morning...... No one is around.
Pat

[TomHaycraft]

I don't like not being allowed to go back in the shop area to see what's going on. I fully understand the reason to not allow. I just don't like it. So, I was wondering about your access.
I keep my rv at home and use a mobile service (I have full access and can ask all the questions I would like). I do like to try and learn stuff for repairs on the road (when I have to...). I'm talking about the breakdowns on early Sunday morning...... No one is around.
Pat

Very reasonable! When there was a need, they invited me back. With the rapport I developed with the tech in charge of my trailer's repair, I sense they would have taken me back if I had wanted to check on the progress, there was never a need though. All in all, I'm confident enough to future work performed there and as noted earlier ... share my good experience with the shop.

Safe travels.

[TomHaycraft]

Adding on to the description that started this topic, we had the trailer out for the first time this last weekend, since the repairs were complete.

With a trip first to CAT Scales, we found the trailer had gain 680 lbs (over Christmas!). This accounts for the heavier wheels, axles and steel plate lining the tops of the wheel wells. At this point, we are 81% of the axle capacity and 51% of the tire capacity (trailer GVWR sticker is null & void with the upgrades and of no use now).

DW and I noticed a few things on the 450 mile round trip. Seemed to be a bit more porpoising (subjective, tough to tell), but objectively, we found our dog's insulin bottle had bounced out of the shelf in the refrigerator on to a shelf on the way out and games had knocked a door open above the rear lounge chairs and had dropped to the floor (due to bouncing), neither of which had not occurred in the 3 1/2 years and 17,000+ miles of towing prior to this.

(1) Tire inflation pressures - based on Maxxis load/inflation chart, with only an average of 1,785 lbs per tire, the inflation of the ST235/80R16s - Load Range E, should only be about 30 psi! Seems a long way from the max cold pressure of 80 psi. I was running about 75 psi cold. Drop down to 50 psi and see how it rides and how the tires wear? Or go all the way to 30?
(2) This trailer has always been a bit light in the pin, but that is how we made it work with the original TV, a 1/2 Silverado. Before new axle and wheels the pin weight was 16.5% of trailer's weight, now we are down to 16.0%. Considering laying in 270 lbs of barbell weights under the bed to push pin weight up towards 18.5%. Worthwhile?
(3) Shock absorbers? At only 8,500 lbs total trailer weight, but considering the ride this weekend, something to consider?

Thanks in advance for any suggestions and discussion this might stimulate. Items (1) and (2) we will play with on our March trip, about 400 miles for Spring Break. Anyone with experience adding the shocks to a "lighter!" trailer like this?

Thanks again.

[JRTJH]

Some things that you might consider:

1. The GVW for the trailer is a "multi-factorial" calculation. Axles, tires, springs, hubs are only part of that consideration. The brakes, frame flexibility/strength, wall structure (wooden on Springdale), size of pinbox, fifth wheel structure and how it is rated are all considerations on the integrity of the trailer. Simply "upgrading axles, tires and wheels" will not necessarily "void the GVW sticker" nor will it "consistently increase the payload capacity. The entire structure must be considered and it's possible (who knows how likely it may be) to create problems by "overbuilding" just as easily as you can eliminate problems.

2. The payload is a component of the trailer "base weight" and GVW. Essentially, with the added weight of the new axles, steel wheel wells, and other improvements, you have reduced your payload. Now, as for pin weight, most fifth wheel towing guides recommend the pin weight be maintained between 15% and 25% of total trailer weight. At 16% you're on the "low end" but still acceptable. The "porpoising" that you noted may be a component of having a light pin weight or it may be a component of the "heavier than normal" suspension/axles. If it were me, I'd be hesitant to start adding "dead weight" to increase the pin weight.

3. The "superstructure" of most fifth wheels is engineered, braced and constructed of metal that is expected to support a specific amount of weight without flexing or cracking. It is, in many "light weight" trailers, not "over-engineered" and may well not have any "extra strength" over the loads that were anticipated.

If you consider the shipping weight, GVW and pin weight of the trailer as it was built, calculate the 15%-25% pin weight, you'll see that the specs call for a shipping weight of 6454, payload of 1521 for a GVW of 7975. That would provide for a "GVW pin weight" of somewhere between 1196 and 1993. Using the weights you posted, with the added 680 pounds of weight from the axles, you've reduced your payload down to about 841 pounds. If you add another 270 pounds of "dead weight" under the bed, you're going to effectively reduce your payload for "other necessary cargo" to somewhere around 571 pounds.

Arguably, you've increased the carrying capacity of the suspension, but that has made the frame/fifth wheel superstructure the "weakest link". I would agree with your statement, "trailer GVWR sticker is null & void with the upgrades and of no use now." However, you still have some serious limitations in frame strength and durability that limit your GVW. Just how much you can "ignore the original sticker" may not be nearly as much as you'd think based on the "over-built suspension" and "factory original frame". You might want to get with someone much better versed than I am to go over the limitations of your "Lippert minimally built frame". You may find that your GVW hasn't changed much at all because of weaknesses other than the axles/springs/tires....

[CWtheMan]

The federal certification label GVWR & GAWR settings remain the same. The only way they can be changed is #1 by the vehicle manufacturer & #2 by a certified vehicle modifier.

[TomHaycraft]

I appreciate the replies. Maybe my choice of words wasn't the best to describe the manufacture weight ratings, I know there is no changing those. Also, to clarify, the increase in axle and tire capacity was not so that I could carry more, the contents of our trailer has been unchanged for the last 3 years. The upgrades were to minimize a recurrence of the troubles the blow out caused last year.

With that said, I also understand I have stepped into the unknown without the ability to perform a full structural and stress analysis to know how changes to the rigidity (and weight) of the frame and suspension, will affect the integrity of the box riding on the trailer's frame.

If I can make this work ... here is a screen shot of my weights and calculations as compared to weight ratings with conditional formatting (green is good, red is bad!). Before the upgrade, I was within 235 lbs of the trailer's GVWR. And, not sure where I got the 680 lb gain, it was 760 lbs!

So, John, to your point of discouraging me from adding weight to the pin, agreed, for now I will hold off. But to the point of tire inflation based on load charts and whether shocks would help ... still undecided there.

[cw3jason]

The recommended tire inflation technique from RVSEF is an individual wheel weighing as you will find one wheel is usually more than the others due to manufactures placing all the heavy items on one side like the fridge. You take your heaviest loaded wheel got to the chart and find out what psi you should run, then bump it up 2 columns to be safe. Then inflate all tires to that spec, so they are all the same (easier to remember than 4 different tire pressures.)

Hope that helps.

[TomHaycraft]

The recommended tire inflation technique from RVSEF is an individual wheel weighing as you will find one wheel is usually more than the others due to manufactures placing all the heavy items on one side like the fridge. You take your heaviest loaded wheel got to the chart and find out what psi you should run, then bump it up 2 columns to be safe. Then inflate all tires to that spec, so they are all the same (easier to remember than 4 different tire pressures.)

Hope that helps.
Thank you, I like the thought of bumping up by 2 columns! Yes, individual wheel weights is on my list of things to do. There is an Escapees location, 2 to 3 hours hours east me that I can schedule with, I've been unable to find anyone with the scales in my immediate area. I am anticipating the curb side tires to be supporting more weight, kitchen is on that side of the trailer and those tires consistently run a few pounds higher and degrees warmer on my TPMS, as compared to the driver side wheels.

Thanks again.

[JRTJH]

TomHaycraft,

Let me see if I can explain my thoughts a bit better: Anyone who becomes a member of this forum, likely during the first 20 minutes of reading has encountered the sentence, "Adding air bags to your truck will not increase the GVW." That same holds true for trailers.

Use this example. Someone has an F150 truck, GVW 7200 pounds with a factory hitch receiver rated to tow 1000 pounds with WD hitch. (consider that F350 axles are rated at 5250 (F) and 9620 (R) If that person installed F350 rated axles under his truck, he would have "increased suspension capacity" to equal an F350, but his frame and hitch would still be limited to the original capacities. He wouldn't "suddenly have" the capacity to tow a 1500 pound hitch load with that 1000 pound receiver and could easily "bend/twist" the frame by overloading the bed of his truck, even though the tires would never squat any at all.

Now, let's look at your fifth wheel. The "factory GVW" is 7975 pounds. Before your mods, the trailer weighed 7740, just under your GVW by 235 pounds. You modified the trailer axles/wheel wells, and it now weighs 8500/8900 (you've listed two weights, one in the top and one in the green below). So, your trailer is now "over the GVW". You're either over by 525 or 925 pounds, depending on which figure you use.

As with the receiver on the F150 in the example, your pin box, fifth wheel superstructure (the raised part of your trailer), the frame and the actual walls/ceiling (which provide rigidity to the entire trailer strength) have not changed. So, depending on which of your figures is used, you're towing either just over 500 pounds or almost 1000 pounds more than all of those components were "engineered" to safely tow. In a fifth wheel trailer, the pinbox vertical load is changed to a horizontal load on the superstructure, then changed to a vertical load at the rear of the superstructure and then back to a horizontal load from the superstructure to the main frame/axles. The structural stresses in the superstructure increase substantially with the added rigidity of the heavier axles and springs as they bounce down the road. How that "boils out" in stress to each welded component in the superstructure is an "unknown to me", but I can assure you that Lippert didn't "engineer that frame" to carry the added weight for an extended time frame with the same reliability as the GVW rating. Sooner or later, something is going to bend or break...

I'm sure you've read a number of posts about rear bike racks, how the frame is not designed to support the added weight on "lightweight trailers". The same holds true for the front superstructure/pin box of fifth wheels. You're overloaded as it sits, you're overloaded when you tow and the action of increasing the axle capacity/adding steel to the wheelwells to prevent damage in a blowout does nothing to increase the strength of the front superstructure of your trailer.

The Springdale is a "wooden frame" entry level trailer. The "hybrid construction" of your trailer does have aluminum side walls bonded with foam, but the front wall, rear wall, roof system and floor joists are all constructed of wood and held together with staples and screws. You haven't "added strength" to any of those structures by increasing the axle capacity.

My "guess" is that if you're fortunate, you won't have any issues, but if you get into any "pot-hole filled construction" or other rough roads, the front superstructure of your trailer that supports the pin box is likely to be damaged from towing your trailer at almost 1000 pounds over the original GVW.

You've got "robust axle capacity" but you're still towing well over the GVW of the rest of the trailer and as "light" as it was engineered to be, it's probably not going to fare well with the added weight. It's the old "silk purse from a sow's ear"

Hopefully, what I've said makes sense to you, if not, I can try to explain it another way....

[TomHaycraft]

Hi John,

Once I cut through your frustration and references to air bags that you started off with, I got to the pertinent information about transfer of load through the superstructure for which I thank you and hope others on the forum have now benefited from reading.

I'll be honest, my focus (and likely the shop's) was on vertical load, not the transfer of inertia and momentum on a horizontal plane from the acceleration and deceleration of the mass, up and through to the pin box. Your point is well made. All the more reason for me to stay vigilant in my quarterly visual check of all welds and weight carrying beams that I can get to in the front half of the trailer.

I'll keep folks on this forum posted on how things play out in the coming years with this setup. It will take some time to save the cash for construction of a trailer that is over-engineered, rather than the mass-produced units which too often are engineered to be just "good enough."

Thanks again.