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....