Winnie Drops and RubberRide Suspensions

reeman · 03-25-2021, 10:30 PM

To be clear on this topic the suspensions on some trailers with rubber torsion are here called the original name of the rubber sprung torsion axle. I will not go into the history, sufficed to say: I once assembled them many many years ago when they were first invented.

They were constructed with very special rubbers which are constricted in liquid nitrogen, put under pressure to shrink them square then quickly slid into the cross axle torsion bar box. Or diamond shaped one if constructed for assembly slightly differently. Which is the case in the particular 3500 lb Lippert branded rubber torsion axle used on our 2016 Winnie drop 1780 with a centre kitchen slideout.

The different weights on the tires because of the kitchen slideout and appliance weight load requires that the trailer be very carefully loaded heavier on the passenger/door side of the trailer. Otherwise the imbalance built in to the trailer can cause undue axle sag over time.

The best way that I can think of to address this inherent imbalance after sitting parked in the cold without causing undue damage to the rubbers or axle seals is:
To jack up the slide side of the trailer as the trailer warms in summer and/or apply gentle heat only to the axle metal box on the slide out side. Thus causing the rubber in the heavier compressed side of the trailer to swell slightly when not under heavy load from the trailer. This will put slightly more pressure on the passenger side of the trailer which should over time wear them down fairly evenly after we apply the correct lift kit.

The rubber in rubberrides should never be heated more than it would be under natural load conditions in Death Valley or in some places in Arizona and Texas IMO.

Unfortunately long period of load under cold condition might cause rubberride torsion suspensions to compress more.
So us igloo dwelling Northerners must be even more keenly aware of the potential phenomena of trailer sag on the slide side. this goes for any trailer manufactured with rubberride suspensions. Either that or open a special bank account to purchase and install new axles every once and a while.

This Winnie Drops trailer's unloaded difference in tire loading weights turns out to be about only 90-100 kg or appx 200-220 lbs. As currently measured in the trailer in the pictures below. Perhaps minus the weight of only 6 gallons of water in the hot water tank in my case today. My total axle load was 2799 lbs today.

Therefore:
An axle which is only rated for 3500 lbs on this particular trailer is a little bit of a skimp on margins but should be just fine if well serviced and properly cared for at all times.

We are currently going through the pain of having the trailer lifted so we can use it here on Vancouver Island. We will keep you posted as to the final damages incurred during the unforeseen venture of purchasing a used Winnebago travel trailer. Happy Trails to you- all: who have joined us on this venture elsewhere out on the lonesome prairies of camper land.

reeman · 03-31-2021, 12:01 AM

This is our first attempt to salvage a 3500 lb Lippert branded Winnie drop trailer axle, that has been unintentionally subject to more wear on the slideout side by the previous owners. Something which was ignored for a bit too long by the previous owners even though the brakes and bearings were serviced and are operating well.

Upon closer examination of the trailer it is also obvious that perhaps a past owner put on a larger size 14 inch tire on the slideout side ( most likely dirt cheap 225 x 14s small truck tires rated for over 2000 lbs ) mistakenly thinking that they would work to take a heavier slideout side load. However the rub occurred does not matter IMO but it is obvious that a tire rubbed the trailer and left a heavy black rubber mark on the fibre glass side wall below the fender on the slideout side. Or worse perhaps someone had a blowout blister rub before the tire went pop from overloading. Who knows?

The axle on our Winnie Drop is not bent at all, as frequently happens on round tubes like the cheap conventional lightly sprung 3500 lb single axle on our neighbours 3000 lb travel trailer with slideout from a different manufacturer that uses almost the same low margins of axle loading capacity on their travel trailer products.

Unlike our neighbours axle: ours is as straight as it came from the factory and there is about an inch of clearance from the new tires sidewall to the trailer wall on both sides of the trailer. It was obviously not a "bent axle" that caused the slideout side tire rub on this particular Winnie Drop trailer. Diamond shaped torsion axles usually do not have that issue and are very slightly stronger vertically than the square or rounded ones. Our ride profile is perfectly fine. The cantilever offset torsion is straight and the tire rides centred perfectly. There is no tow in or out or looseness in the bearings that could cause a wobble.

For safety reasons we have changed out the cheap "Trailer King" load range C 205X14 tires that were wearing evenly but much more quickly (only on the slideout side) most likely due to heavier loading without rotation. We now sport higher quality load range D 205x14s that will take a considerably heavier load. Thus giving us a more reasonable margin of safety and if rotated yearly when the axle and brakes are service should wear perfectly the same and might even last a few years.

With the current setup and tire clearance tolerances: narrow 205s that the trailer came with are the only choice with the stock Lippert axle setup on a Winnie Drop 1780 and no shim spacer to the wheel from the brake drum to move the tires slightly away from the fibre glass walls.

I highly recommend that all owners with this same setup spend the extra 20-30 dollars per tire to install 8 ply 205 st tires instead of the cheap factory supplied 6 ply 205 ones. A very important and serious safety upgrade for anyone who has a similar setup regardless of manufacturer and/or dealer assurances.

Relying upon the low safety margins built into the running gear of today's travel trailers then going down the road at freeway speeds is not exactly a sane idea, at least in my opinion.

On the bright side of things: we did manage to confirm that applying heat gently and very carefully to the steel tube to slightly expand the rubbers contained within them does move the torsion bar inside: thus marginally increasing the ride height on one side of the trailer as suggested in my first post on this topic. The heating might work at least temporarily to restore some of the difference between the amount of bend in the rubber torsion springs on the slideout side. But overheating the rubber would most likely cause it to brake down chemically so we will see if re tempering the encapsulated rubber is effective over time. This process might work on some sports cars that also have encapsulated rubber torsion springs.

Now the difference in clearance from fender to the tire side to side is down to about 1 inch with identical brand new tires under exactly the same pressures. So the axle has sagged up 1 inch more on the slide out side than on the passenger/entry door side. But had over an inch of sag over 4 years of use.

PS:
Our local winnie dealer seems to ignore my wife's phone calls and does not want our business servicing the trailer by applying the specified lift kit for some strange reason or other. You can bet that they would jump if we wanted to trade it in though. At least that way it would quickly and cheaply get a new or refurbished lippert lifted axle installed. They will not use a lippert kit to lift the trailer and insist upon building their own in house oddly enough or so they claim. So something is "fishy in the State of Denmark" about this particular Winnebago trailer that we have legitimately purchased.

Caveat emptor travel trailer owners and happy camping post covid. By then we should be sporting really beautiful lemon trees by applying high end stickers after removing the existing Winnie drop over fiberglass advertising stickers. And be back on the road by the time everyone is vaccinated here on Vancouver Island and all the rich stranded snow birds from everywhere else in Canada and the US vacate the Vancouver Island parks and go home for a while.

Changing the branding slightly on our trailer will certainly be cheaper than getting a legitimate Winnebago dealership to lift an axle without turning it into another senior rip-off career opportunity that costs us untold thousands of dollars! My wife loves the idea of decorating a Winnebago with beautiful lemon tree photos. I can even get them printed up and delivered to us dirt cheap.

Below are pictures of the method my wife and I just tried, it did raise the trailer on the slide out side by over 1/2 inch as measured from the fender to the top of the tire when under the same load as before and after jacking. It would be nice to get over 4 years of use out of a trailer axle. And avoiding the now ridiculous exorbitant expense to replace one every three years before they sag to death.

The tool used to heat the axle was a high heat paint remover that will burn skin or do my favourite job which is finish teriyaki bbq salmon and trout stakes that would burn to a crisp on a bbq without a little finish cooking trickery