Oaxaca and El Tule

Oaxaca city has a central campsite/RV park, but a couple that we’d met during our second stay at the Mayabell campground in Palenque had recommended us the Overland Oasis campsite east of the city in the town of El Tule. It is run by Calvin and Leanne, a Canadian couple who have settled in Oaxaca after travelling Mexico for some time, and they were certainly the friendliest hosts we’ve had since arriving in Mexico. We were made to feel more like guests in their home, than paying customers and I can see why Aten, another guy staying at the site, had been there for more than a month. The plot that we were parked in was in complete shade, under beautiful trees in Calvin and Leanne’s well planted garden; this combined with the super-fast internet connection was enough to make me think of planting roots again.

El Tule itself has most things you’d need, a few shops, a nice park, a lavanderia, etc, and the largest (widest) tree in the world.

The tree is awesome, but looses it's magnificence after walking past it several times a day. One of the main reasons that we decided to stay for nearly week at Overland Oasis is how well connected El Tule is to Oaxaca. On most days we cycled into town, down what must be the longest cycle lane in Mexico. For almost the entire 10km journey into town there is a cycle lane, entirely separated from the highway, running on the route of an old railway line. The weather is cool in the highlands of Oaxaca, and it was a pleasure to get a bit of exercise each day without risking death by heatstroke or by Mexican driving. On the day that we chose not to cycle into town, we paid 6.5 pesos for a bus into town, and 10 pesos for a collectivo back, a total fair of less than 75p.

Oaxaca itself is a fantastic city, with a splendid central square, arguably the best food in Mexico, some huge markets and a long list of great museums and places to visit. Oaxaca is well known for its culinary delights, particularly the mole and tlayudas, but we were delighted by how mixed the offering was. It is just as easy to get contemporary Mexican cooking in Oaxaca as it is to get traditional food, and if you want modern European fare, there are plenty of places for that too. We ate well in the markets and at restaurants, drank some good mezcals in local bars, visited some good museums, and spent a long time walking and cycling around the city. To me Oaxaca city had all the cultural and architectural merit of the grand colonial towns further north (Zacatecas, Puebla, etc), with the artisanal and cosmopolitan sense that we’ve only felt in Oaxaca and Chiapas.

On the whole, Jim has performed well on our vacation so far, but given that we only completed the conversion a few days before leaving him at the docks, I have not been surprised that a few issues have cropped up. With the exception of the brake issue that started in Florida, all of the problems have been minor and we have had no problem working around them or doing simple fixes. A couple of the problems however demanded some attention, and so on our last day in Oaxaca I spent some time working on the truck whilst Naomi was at a cookery course in town. I have most of the tools to do small repairs on the road, but it is nicer to work on the truck when it is off the road and in a campsite. In addition, Calvin is an experienced mechanic/engineer and has a fully equipped workshop with which to help travellers.

The first issue regarded Jim’s engine air system, in particular the intake side of the air filter. The clean side of the ducting, transferring filtered air to the air intake and turbocharger, is in good condition, but the ducting transferring dirty air from high under the truck’s floor, to the filter housing located behind the driver’s side front wheel arch, had completely perished. I have never been particularly happy with the air intake routing and if I’d had the time and money before leaving I’d have rectified it properly. On most recent heavy trucks, Mercedes trucks included, a plastic duct runs up behind the cab, taking air from high above the road and transferring it down to the air filter; this prolongs the life of the filter by reducing the amount of dust in the air, and reduces the chances of a catastrophic hydro lock if water is sucked into the engine in a river crossing. Unfortunately due to Jim’s heritage working for Brinks, the cab and the box body are rigidly connected, and so there is no space behind the cab to run a duct, consequently the truck was originally specified with no ducting attached to the air filter housing, leaving it up to the coachbuilders to work out. With some complex metalwork and a bit of wheel arch butchering, I think that in the future I may be able to run a narrow duct up the side of the cab, but without the time before we departed, I left the air intake ducting as it was left by the original coachbuilders.

The small length of duct, connecting the air filter to a small cage tucked under the floor of the truck had completely disintegrated. The heat and vibrations on the Mexican roads had shaken the duct apart, and all that was left was a mass of steel cord and a load of split latex. Consequently the engine air was being sucked from directly behind the wheel arch, with no cage to prevent rodents or small children from being sucked into the engine. The way that the original coachbuilders had run the duct, it has a restriction as it passes between the floor and the chassis rail, and so I had actually been enjoying a small increase in performance since the duct had split.

I was keen to rectify the issue to prevent any problems, and so with a piece of air conditioner ducting that Calvin kindly donated, I reinstated the ducts to its prior state. I’m not convinced that the replacement will last much longer, but taking the underrun skirt off of Jim, and replacing the duct, took less than two hours, and so I am happy to repeat with a tougher duct if necessary.

The second issue which demanded attention was with the driver’s side grey water tank valve. In my wisdom, I decided to fit motorised valves to the grey water tanks on either side of the truck, one of which had now stopped working. My original intention had been to run a cable to the cab, so that I could empty the tanks whilst we were on the road, but I never got around to this, and presently the only way of operating the valves is with a pair of tail-lift control buttons, one on each side of the truck. As they are now, the valves are no more user friendly than a manual gate valve, perhaps with the slight benefit that I do not have to crouch down to operate them, but with the added complexity of having an electric motor that can go wrong. The passenger’s side valve has always worked well, but the driver’s side, emptying the water from the bathroom, has always been slow to open and close. On one occasion, the valve stopped turning without some manual assistance, but after I stripped the valve and cleaned it out it improved slightly. The problem is that the valve does not operate smoothly and so the motor is not strong enough to open and close it easily.

Eventually, the added resistance proved too much, and with a bang, the valve stopped working completely; this meant that I couldn’t empty the tank at all. I fitted overflow hoses to each tank when I fitted them, and so in the meantime the waste water just spilt onto the floor rather than backing up into the shower tray, but once at a campsite this stops being acceptable. After stripping the valve down, I identified that the valve itself still worked fine, albeit still rather stiffly, and that the problem was with the motor. After opening up the motor, Calvin quickly spotted that one of the gears in the motor had stripped a tooth, preventing the motor from engaging with the valve spindle. The valve only turns a quarter revolution to open and close, and so as a simple solution, I flipped the cog over to the undamaged side and put the motor back together. If the same thing happens in the future, I may be able to disassemble the spindle further and rotate the cog to another undamaged section. As a fall-back solution, Calvin made me a key out of a piece of flat bar, which I can use to manually open and close the valve if the motor fails completely.

I’d have been happy spending even longer in Oaxaca, but the longer we dwell in Mexico, the hotter it will be when we finally make it back up to Arizona. After six days enjoying Oaxaca and relaxing at Overland Oasis we got back on the road, but before finally leaving Oaxaca I felt that it was time to replace the driver’s side steer tyre on Jim. The original drive axle tyres had been in good condition when I bought Jim, and probably had at least 50,000 miles left in them, but they were regional distribution tyres and were completely hopeless in mud and loose surfaces. As a result I had replaced the rear tyres with some chunkier treaded Bandag retreads a while back. At the same time I had replaced one of the steer tyres as it was on its last legs; but now, after another 10,000 miles or so, the other steer tyre needed replacement. In the UK, I may have been OK getting another 5,000 miles out of the tyre, but the dirt roads and poor surfaces in Mexico had begun to cut into the bare shoulder on the tyre, and I didn’t want to risk driving on it any further.

On my way into Oaxaca one day, I found a well-equipped tyre shop who were able to help me with a new tyre, although they only stocked a limited choice. 24.5 inch rims are more common in Mexico on heavy trucks, than the 22.5 inch rims on Jim, and furthermore, the larger 315/80 size on Jim are less common than the 295/80 size. Consequently, Unillantas had only two steer tyres in the correct size, both Michelin, and both expensive. Whilst I am happy to save a little with retreads on the drive axle, I had always intended to put a decent tyre on the front when it needed it, and so I was happy to pay the extra and get some decent rubber. I would have preferred a slightly cheaper tyre from a respectable manufacturer like Hankook or Brisgestone, but Michelin arguably make the best commercial vehicle tyres and so I couldn’t complain.

The two choices I was given were a dedicated long-haul road tyre, and a mixed use tyre designed for on and off road applications. The road tyre, the more expensive of the two is designed to give a good ride, good fuel economy and excellent service life on long distance journeys on well paved roads. 90% of the driving we do with Jim is on tarmacked roads, but the remaining 10% is sometimes on terrible dirt roads, with sharp rocks and loose surfaces on steep grades, and the road tyre is not designed for this application. The tyre I was replacing has gauges in the side wall, and deep cuts in the tread, and I was concerned about putting a similar tyre back in its place. I therefore decided to go with the alternative, the Michelin XZY3, an all position tyre with massive tread and thick ridges protecting the sidewall. If I’d had the money, I would have replaced both steer tyres with XZY3s and replaced the bald spare we carry with the half decent steer tyre, but at around £500 each, I didn’t feel like splashing out.

Unillantas did a professional job with excellent equipment, and we were soon on our way with two balanced steer tyres and the steering alignment checked. We are now on the journey back north, but we couldn’t resist a final jaunt south, to spend some time on the beautiful beaches of Oaxaca.