The Black Art of Towing Part Eight - Where We Went On Our Holidays

It's fair to say that towing in our part of the world is fairly easy. Flat is a bit of an understatement for the terrain hereabouts and bowling along our quite excellent highways is a doddle, even for a minivan. 

We've towed out to the Niagara area (and beyond) on a couple of occasions and it's interesting to note the gas mileage is always better towards Niagara than when coming back; it really must be down hill as we are heading for the sea, really. 

I think I prefer the non-highway, Provincial roads for towing. They're all in quite good condition and the speed limit is 80 Km/h (50 mph), so it's easy on the Toadmobile and easy on the mileage, too, as we can easily get 14, even 15 miles to the US Gallon when not on the big highways.

One of our regular trips is up the eastern side of Lake Huron. The road, Route 21, the Bluewater Highway (not a highway at all, but a good road all the same), does start to rise and fall a bit, and it's not as arrow straight as many roads in the locale, so it makes the trip quite interesting. I tend to stick to the speed limit and I'm always surprised at how many people come haring past us as they must be really flying. Mind you, sometimes I think I'm the only one in Ontario that sticks to the limits.

Our first big trip was to the Finger Lake Region in Upstate New York. It's not so far from home but we didn't leave until 4.30 in the afternoon and what with a border to cross and the Friday night traffic to contend with, we didn't arrive at the campground until after midnight. A lesson learned there was to always allow more time than you think you'll need. The Sienna towed perfectly, even up and down the steep hills that border the lakes. Coming back we encountered some seriously horrible weather with high winds and rain, but the Toadmobile kept chugging on, passing other trailers struggling in the wind, and even coasting past some eighteen wheelers on the Niagara Escarpment at Hamilton. Gas mileage was a fright but I suspect it would have been the same for anyone towing in those conditions.

Our really big trip was eighteen days in the US, heading down to Orlando in Florida and back via New Orleans, Birmingham AL and Knoxville. The I75 is an easy drive but we set ourselves a target of around 400 miles each day and achieved it comfortably. The grades as you enter Tennessee are long but apart from a slight drop in speed, the Sienna coped admirably. Our only testing pieces of driving were heading through the centre of Atlanta, the first time I really forgot about the trailer so I could concentrate on where we were going, and a drive east of Birmingham where we crested a ridge that really was quite steep! Our reward was the following day when we took a rural drive up towards Chattanooga and took in some lovely switchback roads in the Alabama countryside. 

One section of that day's run was on the I59 where were caught up in some construction work. Long story short, in the right hand lane the right side wheels of the trailer kept dropping down a step in the pavement that was a temporary widening measure for the road. At 50 mph it wasn't nice having Towed Haul lurch right then left again as it went up and down the step. I noticed that the Semi drivers were all in the left lane, tucked up close to the concrete barrier. I reasoned that they must have been having the same problem and had chosen a run close to the wall rather than up and down the step on the right. So, I copied them and whilst I had to keep an eye on my distance from the wall, it was better than staying on the right. Both car and trailer came through unscathed, even after 15 miles of construction work.

On the Florida run we were quite heavily loaded with us, the Tadpoles and our gear. As the weight distribution system is properly tuned, I'm always confident that the weights over the axles are well distributed, but I reckon we were close to the axle limits.

In the rear view mirror, on the Ambassador Bridge, heading into Detroit

At High Falls State Park, near Macon, Georgia

So, towing up hill and down dale isn't really worrying the Sienna, nor worrying me. Long days have presented no issues, either, even in very high temperatures. Sure, the altitudes are all minimal and I'm sure the performance in the Rockies will be somewhat limited. However, all the indications are that Toadmobile will pull us through, in more ways than one!

I think this entry pretty much wraps up the Black Art feature. However, if you keep checking back, especially after April, you'll see some of more detailed weekend blogs. I'm not letting on about the big summer jaunt for fear of jinxing it, but we are planning to visit Liberty Harbor RV Park in New Jersey. Check out their website here, to get a flavour of its position relative to Manhattan. That will be a fun trip!

Anyway, thanks for reading and please do drop me a line if you want any more details about how we tackle the Black Art of Towing.

The Black Art of Towing Part Seven - Progress so far

Ironically, I couldn't find a photo of a broken down Sienna...

So, how has it been for us? Has the Toadmobile been stranded at the side of the road in a pall of oily smoke? Has the transmission dropped out onto the road? Has the hitch fallen off?

In answer to those questions I can categorically say that we've had not one ounce of trouble related to towing (or anything else), apart from a slow flat when we picked up a bolt in one of the tires whilst on the Gulf Coast. I still managed to drive to Tennessee before I thought it needed some repair work done!

I've kept the Sienna serviced in accordance with the Toyota schedule over the two years we've been using it, with one additional oil change after the big 2011 trip to Florida. Over the 30,000 Km (18,640 miles) on the clock, we've towed for about 10,500 Km (6,524 miles), which is roughly one third of the total. Our local Toyota dealer has, on my request, reported that both engine and transmission oil look fine and, given that the oil in the transmission doesn't need changing until we clock 96,000 Kms (60,000 miles), we appear to be good to go for a few more seasons yet. 

Wear and tear on the Sienna isn't apparent, but I think it helps that I'm a fairly careful driver. I keep my speed down, brake early and accelerate gently and I've always been quite gentle on my cars. By applying this same idea to towing, I think I don't abuse the car in any way and, as an added bonus have managed to get good gas mileage with an average 12 miles per US gallon over the past two years when towing.

When towing in warm conditions, particularly on a long run, you can feel heat through the foot well floors but this, if other Sienna drivers are to be believed, is quite usual when under any kind of load. The engine coolant temperature has remained steady, even when towing in temperatures around 38C (100F), and as yet no warning lights have been triggered, not even the transmission oil light.

That said, on our first trip towing, heading away from the dealer's lot, I did spin the wheels of the Sienna quite violently trying to turn left across traffic (forgetting the trailer was there I think) and managed to get a warning light come up on the computer screen. The car didn't seem affected and when I checked with the Toyota dealer they could find no trouble so just reset the error code and it's never reappeared since.

The brakes have shown no signs of additional wear and when towing, the whole thing stops more quickly than when not towing; that's where eight brakes are better than four, even with an additional three and a half tons to lug around.

The hitch receiver remains firmly bolted to the car although there is a very slight change of shape in the lock pin hole in the receiver box, due probably to some less than fantastic steel used in its construction; three and half tons dragging on it can have that effect, I think. 

The weight distribution system has been adjusted to take account of the additional spring that the bars develop after some use; I've added two bolts in each of the chains which shortens their length up by one third of a link per bolt. It will need a little more adjustment this season so I'll drop the two bolts on each side and just hook on one full link higher. This is acceptable wear given the use and quite normal. I don't know how long the weight distribution system is supposed to last but it's looking fine at the moment. 

I keep the Sienna's tires at the recommended 35 psi and they are looking quite normal for their age. When I need to buy new I shall consult with Can Am as I know there are better tires out there.

When we were buying the Airstream, the people at Can Am told us that they do keep track of the tow vehicles they set up and they did tell us that no Sienna drivers had reported any tow related problems, even over many years and countless thousands of miles. They pointed us to this blog - Not@Home - written by a couple of friends of Can Am. Ontario residents Anne-Grethe and Einar (who regularly give talks about their experiences) took a 31' Airstream towed by a Toyota Sienna up to Tuktoyaktuk, way above the Arctic Circle on the coast of the Beaufort Sea in Canada's North West Territories. If they can tow all that way with their Sienna, often on dirt roads, I know I'll be OK on the big highways of Canada and the US.

So, no ill effects from the towing and I don't think any other Sienna owners have reported towing related issues. We haven't done anything too outrageous with Towed Haul in tow but in the next instalment I'll detail a few of the trips we've done and describe how we've managed...

The Black Art of Towing Part Five - Other Mods

So, what else have we done, apart from the hitch, weight distribution system and sway control, to turn a Toyota Sienna into the Toadmobile? Read on...

Given the additional load that Towed Haul is imposing on the Toyota, some help to cool the transmission oil is required. Can Am's solution was an additional oil cooling kit, something like the one pictured above, installed behind the front grille. Whilst I haven't monitored the transmission oil temperature so far, we've certainly had no problems, even when driving in seriously stupid hot weather on Florida's Gulf Coast and back up through the Southern States. The people at our local Toyota dealers' also reported that the synthetic oil looked as good as new, and that was after about 10,000 miles towing.

Next came the brake controller, specifically the Prodigy P2 Proportional brake controller, pictured above. This is installed in the car and monitors the braking performance of the car and trailer and applies the electric trailer brakes in proportion with the brake effort applied to the car's brakes. Each wheel on the trailer is braked so even though the Airstream has drum brakes, there's still formidable braking power to be utilised on top of that provided by and for the car. Simply put, the trailer can stop itself; indeed, when hitched, the car and trailer will stop in a slightly shorter distance than when the car is on its own.

Brakes are one of the areas that make the sceptics out there very concerned. I think they acknowledge that the Prodigy can get the trailer to stop, but they worry that if the trailer brakes should fail then the brakes on the car alone would not be able to bring three and a half additional tons to a halt, at least not safely. It's not an unfounded worry as the possibility of trailer brake failure is greater than failure of the car's brakes, but I have no intention of testing the situation, especially as it may never happen. I draw comfort from the thought, though, that the load being pulled by the tractor of a semi-truck (Tractor/Trailer, articulated lorry) often weighs more than three times the weight of that tractor and they manage quite well over many millions of miles of travel - like me and my tow vehicle, they work on the basis that if it had to, the tractor could stop its trailer at least once in reasonable safety, should the trailer's brakes fail.

Part of Can Am's set up was to provide a pair of McKesh clip on mirrors, fixed securely on the Toadmobile in the photograph above. Not only is it desirable to be able to see behind your trailer, it's also a legal necessity in most parts of North America. The Mckesh items may not look very sexy but they mount and demount in seconds and are pretty steady, even at speed. There are two issues that I have with them, though; firstly, that webbing can vibrate something rotten if it's windy and secondly when it's raining the mirrors get pearls of water on them quite quickly and become difficult use. The vibrating webbing has been mostly solved with the addition of a small piece of foam positioned near the lower door clip, a cheap and simple solution. The wet mirror can be solved by tying a piece of string to the mirror's supporting shaft; the string blows against the glass and breaks up the pearls of water, thus making the mirror usable again.

Finally, a modification that I made myself was the addition of a Scanguage II. This clever little device plugs into the car's OBDII port and displays, amongst many other things, sensor information including transmission oil temperature. To be fair I haven't managed to get that function working yet but it'll be great when I do! (After-note: It seems that the Toyota's sensor is a simple switch showing OK and Not OK. I'm going to have to get a new sensor and most probably a specific gauge for that pesky transmission oil temperature).

For my final discourse on this subject in the next blog entry, I will be relating some of my towing experiences, good and not so good. Stay tuned....

The Black Art of Towing Part Four - Sway

Didn't Rosemary Clooney sing about sway? Probably not about trailer sway, though.

Trailer sway, more properly called "Yaw", is where your big heavy trailer behind you starts to oscillate around the towing ball and, if not checked, can have disastrous results. I did read a big academic study about trailer sway but you'd have to be a trailer nut like me to want to go through that so I'll just include this link here for further reading. It's really a commercial for the Hensley Arrow hitch but it's quite concise and easy to read. There is a notable exception to their causes of trailer sway in that they don't mention speed as a cause, however it's pretty good other than that. If you read further, you'll see that there are methods of controlling trailer sway and not all of them made by Hensley Manufacturing!

On our set up we use the simplest method of sway control and that is to dampen it with friction. We have a pair of sway control bars like the one pictured above (conveniently labelled "Sway Control"), one each side of the ball. They work by having one end connected to the trailer and the other to the hitch. Each bar has an arm that extends or retracts and the trailer pivots on the ball and by means of a pressure pad and some brake lining material, the arm's movement is restricted but not stopped completely. This dampens the side to side movement of the trailer and should a yaw situation occur then the pivoting action of the trailer is greatly restricted. 

I'd seen a similar application in steering dampers for motor cycles; the problem and the cure are identical. The friction method only dampens sway and there are other, more sophisticated methods that not only dampen but actually prevent sway by using opposite forces in the design of the hitch to counter the swaying movement. That said, even the no-sway hitches sometimes won't resist the force of a wildly swinging trailer and the hitch itself will fail, but fortunately that situation is unusual.

Despite having the least sophisticated system, albeit that we have two units operating, I've not had any sway issues when towing. When the big semis come past you can certainly feel the pull, but I'd not call that sway and I've never felt uncomfortable towing. That said, I'd never tow without sway control because no matter your trailer and no matter your tow vehicle, you will experience yaw if you don't do something to counter it.

In the next instalment I'll look at some of the other modifications made to the tow vehicle to help it in its towing duties. Watch this space....

The Black Art of Towing Part Three - The Hitch Receiver

The hitch receiver is the bit of the towing system that's bolted to the car. How it's bolted is, obviously, pretty important because there's scope for all sorts of unpleasantness if it's not right.

Because the Toadmobile was supplied without a hitch receiver, I'm going to talk about the after-market variety. There are lots of vehicles that come with a factory fitted item which may or may not be up to the task. Factory fitted or after market, though, they all need inspecting by an expert and nothing should be taken for granted as they all have their pros and cons. Our hitch receiver was chosen, and modified, by Can Am RV; we most certainly would not be towing without their knowledge and assistance.

This is what our after market hitch receiver looked like before modification and before installation. The brackets at the end bolt onto the rear of the Sienna's body, some distance from the rear axle but at the maximum width of the car. The receiver box in the centre, the bit where the hitch head is fitted, has a 2" opening and is rated at Class III/IV.

Here's how it looks, installed on the Toadmobile; complete with humorous insert in the receiver box!

I mentioned before that the hitch receiver had been modified; the standard item isn't sufficiently robust to take a very heavy load, nor does it transfer sufficient weight forward when the weight distribution system is fitted. This is where the experts at Can Am RV come into play and it is they that have welded two three foot long L section steel bars onto a plate behind the receiver box. These bits of steel are then bolted to a point on the car just behind the rear axle.

Here is the modification as installed on the car. The bolting point can be seen on the left of the picture and the welding, with an additional plate, can be seen on the right, just behind the receiver box.

This modification adds rigidity to the device to counter the upward and forward forces exerted by the weight distribution system, adds an additional bolting point to the car as a fulcrum, and helps to transfer the weight on the hitch forward down the length of the car. Without the modification, it's unlikely that this particular hitch would do the work required of it, for our trailer at least.

One point worth mentioning here is that the receiver box is tucked under the car. The closer it can get to the rear axle, the better, as the distance from hitch to rear axle is critical; the shorter the better. 

A quick look at the hitch head under tension (above) will show how close it is to the back of the car, so much so that the folks at Can Am RV have cut away sections of the head to allow it to be so close; these are the areas within the circles.

Going back to the factory fitted receivers, sometimes even they need similar modifications and for all the same reasons. Just because it's factory fitted doesn't mean that it will work particularly well; auto manufacturers are rarely experts in towing.

I hear a lot of people say that using a car that is of "Unibody" construction, that it is pressed steel and having no main frame or chassis, for towing is asking for trouble. Unibodies are said to twist and flex and fail to provide sound mounting points for hitch receivers. Well, this unibodied car is plenty rigid and does, with the receiver modification, provide robust mounting points. Indeed, the chassis on a pick up truck is really a very narrow frame that is more prone to twisting than the wider unibody. Receiver mounting points are necessarily narrower on a truck and whilst a chassis will transfer weight, it's all done down a narrow spine and not spread as widely across the vehicle as it is with the unibody. I know that I won't convince the traditionalists who like their chassis, but the unibody works for us.

We've run this set up for two seasons now and the hitch receiver has proven to be reliable and effective; clearly the receiver is doing its job and everything works as it should.

In the next instalment I'll be looking at what's been done to counter sway, a very real issue when towing anything...

The Black Art of Towing Part Two - The Weight Distribution System

So, what is a weight distribution system and do I really need one?

Well, it's a method of spreading the weight of the trailer's tongue around a bit and yes, I really do need one. 

If I were to hitch the trailer to my car without weight distribution then the entire 1000 lbs or so of the trailer's tongue weight would be resting at a point some three to four feet behind the rear axle, putting all the weight on that rear axle. Quite apart from exceeding the axle's weight limit, the back of the car would be almost on the ground and the front would be pointing skywards. Even if I could stiffen up the rear suspension to stop the back of the car from dropping so low, the front axle, which is the drive and steering axle, just would not function as it should.

What's required, then, is a set up where I can push that load forward so it can be spread across both front and rear axles, and for good measure transfer some of it back to the trailer itself. Fortunately, there are weight distribution systems to do just that.

Above is a photograph of the system we use, shown without the trailer. The hitch head is to the right, with the ball clearly visible. The two spring bars fit into the bottom of the head and provide the "lift", whilst the chains on the end of the spring bars attach to two hooks which are fitted to the A-Frame of the trailer. This is a relatively unsophisticated system and deals only with weight distribution; there are others like the Hensley or the Propride PPP that deal with both weight and sway. However, the Eaz-Lift is lighter and cheaper and for us, seems to do the job perfectly well. I'll deal with the sway aspects of the hitch in another blog entry.

The next photograph above shows the system fitted to our trailer, the spring bars are under tension and providing lift. Also pictured is one of the sway control bars and the safety chains, neither of which has any function to support weight distribution system but are both very important in their own right; more of that later.

The picture also shows the hitch head very close to the rear of the car's bumper. When not under tension, the hitch head sits a few inches lower and a few inches away from the bumper, but the action of the spring bars is enough to lift the trailer's tongue (all 1000 lbs of it) up and push it forward, clearing demonstrating the lift and weight forward transfer properties of the system.

The method to attain the tension on the system is a process that I've never been comfortable with but it is the recognised way of doing things. Firstly I back the car up to the trailer and using the trailer's jack, I lower the ball receiver onto the ball and lock it into position. Then I use the jack to lift the tongue of the trailer and the car, up to a point where the car's rear wheels are just about to leave the ground. The trailer's coupler is holding the weight of the car and it's being supported by the hitch receiver! I fit the spring bars into the hitch head and attach the chains to the hooks on the trailer's A-Frame, to a point on the chain that was pre-determined by our hitch riggers, thus establishing the correct amount of lift and forward weight transfer. Then I lower the trailer and car by retracting the trailer's jack. As the weight is lowered, the spring bars take up the tension and start the lift and weight transfer. Once the jack is off the ground and the car is settled on its suspension, it looks like the picture above, with the hitch head up and forward rather than down and back as you might expect.

It's now that about two-thirds of the tongue weight is being transferred to the car and about a third back to the axles of the trailer. If the hitch is rigged correctly then the weight transferred to the front axle of the car should keep it in proportion to the weight on the rear axles and the car and trailer should appear level, or thereabouts. The weight on that front axle needs to be in proportion to the weight on the rear axle for it to function properly and that's the aim of the weight distribution system.

Now we see the whole combination sat level on the road (in Bayfield, Ontario), just to show how it all works.

If you're wondering about the principles of weight transfer, I've best heard it explained as being like a wheelbarrow. You couldn't pick up a wheel barrow full of bricks just by grabbing the barrow bit, but by using the arms of the barrow as a lever and the axle of the wheel as a fulcrum, it's easy to lift up. The levers on the weight distribution system are the wheel barrow's handles, the fulcrum for the lever is the point(s) at which the hitch receiver is bolted to the car and your feet are the trailer wheels. I think that's easy to understand and sums it up nicely!

In assessing if a tow vehicle will work, rather than fixating on the manufacturer's tow rating, you should be looking at what load the axles and the tires will take. When you're doing that, you have to consider the two-thirds of the trailer's tongue weight that is now spread across your car because it will affect what you can carry. Fortunately, that 'payload' figure is quite generous for the Sienna so I do have the ability to take passengers and luggage without overloading the axles; it's not the same for all prospective tow vehicles, though, and sometimes the much vaunted pick up truck will be tight on what the axles can handle when loaded and hitched.

One of the less well documented advantages of having weight distribution is that it really makes the two parts, the car and the trailer, act as one with the weight spread over all four axles. The trailer is responsive to the movements of the car and vice-versa, and when towing something that weighs three and a half tons, any advantage you can get is always very welcome.

The Toadmobile couldn't tow this trailer without weight distribution, but some vehicles are sufficiently strongly built that you could just hang the trailer on the hitch and drive off. Similarly, I could tow a light weight trailer without weight distribution. However, without the system, all the weight of the trailer is weighing on the rear axle, taking weight from the steering axle at the front, which is never good. It matters not how big your tow vehicle or how small your trailer, weight distribution will always help the towing process.

I have to point out here that I didn't set the weight distribution system up myself, although it's a reasonably easy thing to do. I prefer to use the services of an expert, for us Can Am RV, and know that everything will work as intended.

My next blog entry will be about the hitch receiver, the bit bolted onto the car. That's as critical as the weight distribution system and needs to be set up correctly for the weight distribution to work effectively. So, look out for the next instalment in The Black Art of Towing, coming to a device near you....