2720SL Blowout -- issues, WOW terrible

[Andromeda]

With a driver side blowout in June, my 2720SL TM dropped to the road and the plumbing was sheared entirely off. To resolve this problem, I hope to accomplish several changes including:
1. Move the plumbing forward nearer the wheel for improved road clearance
2. Install a 2" lift kit to provide clearance for 15" tires and rims
3. Install 8-ply tires to achieve a load rating of 2,400 lbs. per tire
4. Install skids to avoid dragging trailer components.

Background:
The existing 14-inch tires and wheels supply minimal and marginal load capacity. Considering the loaded trailer, according to the TM certificate reaches 3,956 lbs. the existing tires rated at 1850 lbs per tire in primo condition, with a subtraction of 400 lbs. tongue weight, barely get by in my book (3700-400=3300 lbs. load per pair). This loading fails to account for higher loads in turns or on bumpy roads, or other irregular conditions and lastly, reduced tire capacity after only a couple of years of service.

Unfortunately, the small existing wheel well cannot accomodate a 15" trailer tiire due to width limitations in the well. I tried and failed.

Clearly, the 2-inch lift kit might provide the needed wheel well clearance. In Houston, an I-45 N trailer shop can deliver 8-ply 15-inch wheels and plain rims for $125 each, if you need a cost point.

If clearance issues still exist with the lift kit, that means modification to the wheel well. Let me know if you tried this.

To achieve even more plumbing clearance, I hope to move the larger items closer to the left rear area of the wheel well.

Additionally, to avoid other damage due to blowouts, I plan to mount skid plates bolted to the frame that drags the ground to minimize damage, an item that should cost little. This follows the same concept used on aircraft.

There should be a torsion bar adjustment that would raise the camper by increasing the torque position of the bar. I can't find it. Anyone tried this?

Since I know many others have faced this issue, according a TM mechanic from a defunct shop here, I request any tips and sources for materials for my repairs.

I found the posting by wmiller3 on "Retrofitting the lift kit" very helpful. However, he fails to say where the lift kit was purchased, or I missed it.

At nearly 72, this is hard work for an old man.

Thanks

The lift kit comes from TM. But in a pinch you can make one yourself. It is two pieces of box tubing, ( 2 inch ? ) drilled to match the current holes in the TM frame / axle and 4 longer bolts with nuts and washers. Try TM first. Mark everything as you go. I did one side at a time after marking eveything. Had to grind / cut some tack welds but other than that it just takes time. Sorry to hear about the plumbing.... been there.... done that.... Not just TM with that problem. Good luck!

[wbmiller3]

I bought the lift kit from TM just a few weeks before they went into bankruptcy. It was $45.00 plus shipping at the time. I don't remember how much the shipping cost but the total price was under three digits.

Let me know if you have any other questions. I'm in Houston as well.

[Bill]

I understand that you are upset that you had a blowout, but the tone of your original post is not acceptable on this board. If you want to discuss problems and solutions, that's fine - that's what this board is for. But name-calling contributes nothing and will not be tolerated.

Please restrain yourself in the future.

Bill

[Andromeda]

Axle capacity is one item I left out that could cause another problem. There should be a marking somewhere on the axle that states this rating. Otherwise, unless someone knows the rated capacity, I will ask TM.

Regarding my name calling, I used very benign names to embarrass the responsible designer, half in jest and half in irritation. After all, I will spend plenty to get this repair completed, one that would be totally unnecessary with proper attention to detail. Still, I could have left it out and I will abide by your rules.

I also hope to warn other owners to allow them the ability to take action before a disaster, one they might avoid. By simply adding a lift kit and 15 inch wheels and 8-ply trailer tires, they reach a combined capacity of 4,800 lbs. on the tires, according to brand and rating, plus 400 lbs. more on the hitch, a totoal of 5,200 lbs. Naturally, tire clearance in the wheel well must function.

Taking the calculation for a standard unit (mine is a 2006 model) a little further regarding tire capacity consider:

With the tires carrying a rated 3,700 lbs. (maximum available in 14" size) and the hitch having 400 lbs., the total available capacity is 4,100 lbs, with the tires in top condition. At a full load of 3,956 lbs, according to the TM certificate, the safety margin is only 144 lbs.

Friends, that margin of 144 lbs. seems quite inadequate to me.

What might save some of us is a travel weight well below 3,956 lbs. Still, do you know your loaded weight?

I saw several replies this morning. Thanks for your assistance.

[ZekenSpider]

Originally Posted by Andromeda

Axle capacity is one item I left out that could cause another problem. There should be a marking somewhere on the axle that states this rating. Otherwise, unless someone knows the rated capacity, I will ask TM. .................................................. ...............................Taking the calculation for a standard unit (mine is a 2006 model) a little further regarding tire capacity consider:

With the tires carrying a rated 3,700 lbs. (maximum available in 14" size) and the hitch having 400 lbs., the total available capacity is 4,100 lbs, with the tires in top condition. At a full load of 3,956 lbs, according to the TM certificate, the safety margin is only 144 lbs.

Friends, that margin of 144 lbs. seems quite inadequate to me.

What might save some of us is a travel weight well below 3,956 lbs. Still, do you know your loaded weight?

I saw several replies this morning. Thanks for your assistance.

Of course you are generally correct in your analysis of the TM design safety margin. It has been discussed many times on the forum. I'm sure that is why TM decided to go to 15" wheels and tires on all models in 2010. However, in defense of the original TM designers, remember they were trying to get an RV that was very light and easy to tow. As time went on, customers demanded more options and ultimately customers began to overload their TM's (because we always "need" to carry more stuff).

As far as I know, the axle has not changed. The axle tube has a number stamped on it that you can look up on the Dexter Axle web site. It will give you the design weight capacity. I know that TM claims the design axle weight (GAWR) = 3,500# prior to 2004. Since 2004 they claim it is 3,500# plus TM weight not carried by the axle = 3,640#.

Attached is a study I did a year or two ago about TM users actual weight experience on several TM models compared to the factory advertised details.

In addition, it is important to understand that trailer RV tires will not last more than three to five years even if they are not used. Much of the damage to TM waste water plumbing is caused by tire blowout when the tread belt whips around and rips the plumbing off....even if the TM frame does not hit the ground. So...part of your upgrade scheme should include a plumbing protector.

Regards,

Jerry

Originally Posted by Andromeda

Axle capacity is one item I left out that could cause another problem. There should be a marking somewhere on the axle that states this rating. Otherwise, unless someone knows the rated capacity, I will ask TM.

I'm less worried about axle being overloaded then the tires to be honest. But, yes, you shouldn't overload anything.

Friends, that margin of 144 lbs. seems quite inadequate to me.

It is, and it's worse if you use a WDH (since it would be easy to transfer weight to the tires) - it's one reason I don't use one. Also, one side of your trailer is likely heavier than the other (appliances, water tanks, etc). Your calculations assume balanced load, which I don't think is accurate.

What might save some of us is a travel weight well below 3,956 lbs. Still, do you know your loaded weight?

My 2916 with A/C, awning, dual batteries, and solar panel is 2,860 lbs at the trailer axle, 500 even at the tongue. TM claims 2991 for UVW, so I've got about 400 lbs of extra "stuff" the way I camp (I suspect TM's UVW doesn't include things like full propane bottles or the extra battery). I want to say those weights were with no water (that would add 400+ lbs).

Originally Posted by Andromeda

With a driver side blowout in June, my 2720SL TM dropped to the road and the plumbing was sheared entirely off. To resolve this problem, I hope to accomplish several changes including:

Tanks

Sorry for the mess, I can only imagine what you are going through. Do us a favor please...edit your signature to include info on your TM and TV. It will help us make suggestions when you experience problems.