My previous post at Iran Update gave a mere notification that we had some vehicle problems. It is about time I tried to bring everyone up to date on our Shiraz Odessey.
Our odessey started on the morning of October 4th. After a hectic night talking to people in the parking lot at Persepolis we set off to find our way into Shiraz. Just south of Persepolis we passed through a small town called Marvdasht and then headed up the on ramp to join the main freeway to Shiraz. All of a sudden there was an almighty crunching sound from the vehicle and a lot of bumping. We stopped almost immediately. A small experiment determined that the vehicle would not move and moreover any attempt to move it caused some horrible sounds. As you can imagine our first thought was what the … do we do now?.
Fortunatly we had already made contact with a gentleman named Mr H (name withheld to protect the innocent) in Shiraz (Mr H is a guide whose name we found in one of our guide books) with the goal of having him find us a hotel in Shiraz that would have a parking lot big enough for our truck. So being desperate I called Mr H and told him of our problem/plight. About 20 minutes later a friend of Mr H's arrived with his car full of tourists on a tour. He looked at our situation, talked to a nearby police traffic patrol who called a tow truck for us.
Another 20 minutes later a truck with a huge crane on the back arrived. At my instruction they hooked up to the front of our truck and we looked all set to get going, but a very small movement forward made it clear that the problem was in the rear axle not the front.
I had (incorrectly) assumed the problem was with the front axle as that is the one that has an oil leak and the one that I have been regularly topping up since Mongolia.
So we unhooked the front and started to think about how to connect the truck and crane to the rear. This was far from obvious. As the camper box runs all the way to the back of the truck chassis and there is no obvious lifting point at the rear. Eventually we had to take down the spare tire and make a very precarious connection at the rear. The head of the crane was perilously close to the rear wall of the camper box and Nina and I were both concerned about serious damage to the camper.
I forgot to mention that to connect to the back of our truck the tow truck had to be facing into oncoming traffic.
With the connection made the tow truck inched its way back down the on-ramp into the oncoming traffic. This did not seem to phase the traffic as it continued to race up the ramp onto the freeway at its normal breakneck speed.
After about 20 minutes of negotiating crazy traffic we arrived at a spot in the main street of Marvdasht. We were told to wait as a mechanic was coming to inspect the vehicle. After about 10 minutes this turned into it's Friday (prayer day) and the mechanic is not working. After a little more discussion one of the guys, Mr S, in the crowd offered to let us park the truck in his garage/yard.
Getting our truck into the garage's yard was an exercise in terror and amazing driving, but we were eventually inside a secured yard and unhooked from the tow truck.
After some hard negotiation between Mr H (over the phone from Shiraz) we paid the tow truck guy 5,000,000 Rials (about USD160). The truck driver left. Mr H said he would come and pick us up in about an hour. And Mr S, the guy that owned the garage/yard, started to disassemble the apparently malfunctioning wheel hub. That exercise took a while as the U500 wheel hubs are very different to most trucks and there was some learning involved. But eventually the thing was in pieces and we could see the problem. The main outer bearing that supports the full weight of the truck had shattered and was broken into little pieces. The broken bearing had released its rollers into the hub and they had proceeded to break pieces out of the teeth of the two gears that provide the hubs reduction function.
In the photos associated with this entry, the nature of the hub can be seen. At the top of the hub is a small diameter gear wheel that is connected to the axle shaft. The small gear wheel drives a larger, lower, gear wheel that is connected to the road wheel. These two gear wheels reduce the speed of the axle shaft so that the road wheels turn at a lower speed than the axles. Both these gears were damaged. The big one that drives the wheel had damage to the teeth, and also to the surface that fits into the large now broken bearing in the case cover.
At that time we thought that if we could find a replacement for the shattered outer bearing we would be OK. Mr S assured us that he could weld up the broken teeth in the gear wheels and fix the damaged bearing surface on the large gear wheel.
So at that point Mr H drove us into Shiraz to a hotel he is connected with and got us a room in that hotel even though it was fully booked. Thus ended phase 1 of the saga.
The next phase was the search for parts. At the time we were only looking for a replacement for the large outer bearing that had been destroyed. Mr H took it upon himself (to our relief) to do all the leg work on this. Many visits to the truck centers of Shiraz and many calls to parts shops in Tehran eventually found 2 instances of what we hoped was the correct bearing.
Throughout this I had been in contact with Rob Pickering in Colorado to see if he could source the parts for me if that became necessary. As it happened he could, they were on hand in his shop. All I had to do was find a way of getting them into Iran.
This phase took 2 days, Saturday and Sunday.
With a replacement for that large bearing we returned to Marvdasht to find that Mr S had, as promised, fixed the chips in the teeth and cleaned up the bearing surface on the shaft of the large gearwheel. More over the replacement bearing was a perfect fit onto the cleaned up bearing surface of that big gear.
The bad news was that the outside diameter of the replacement bearing was 3 mm too small and as a result the bearing did not fit correctly into the hubs outer case.
After some thought a plan was devised; a spacer would be fabricated to reduce the diameter of the slot in the case so that the bearing would fit correctly.
Also during this visit to Marvdasht more attention was given to the bearing on the inside of the large gear wheel and it was decided that this bearing was suspect and should be replaced. That bearing was removed and we returned to Shiraz for the night with Mr H promising to find a replacement for that inner bearing.
As promised Mr H arrived at the hotel the next morning with a replacement for the inner bearing. So after Mr H did some of his main job we returned to Marvdasht in the afternoon to complete the reassembly.
The reassembly went without a hitch and once we include time for photos and laughter and goodbyes took probably 4 hours.
So the truck was ready to move again. Nina and I got in and we followed Mr H to Shiraz and the truck district where he found us a place to park in a yard full of trucks and other equipment.
The bad news was that the newly repaired hub seemed to be running at a higher temperature than the others. Mr H and I debated whether this was a problem or something of no-consequence. But since the day was done and it was dark we postponed any action on that until the following day.
So on the morning of Tues 8th Mr H shuttled us back to that parking lot where we were joined by a relative/friend of Mr H's who had some expertise in bearings and machinery. The idea was that we would drive our truck for an hour or so, following Mr H's car, and would stop periodically to see if the temperature difference between the repaired hub and other hubs was "significant". We even stopped at one point and jacked up the two rear wheels in turn to see if we could feel any difference between the behaviour of the two hubs.
Conclusion - indeterminant. The repaired hub definitely runs hotter but we don't know whether that is a problem.
At this point I don't think we have much choice other than to continue our journey with the repaired hub as it now stands.
A more complete repair would require getting access to as many as 10 new components that collectively might weigh 100+lbs. That just does not seem feasible.
Our only viable option therefore seems to be - continue the journey, checking the hub very frequently with the hope that if it starts to fail again we will detect it before the truck becomes completely immobile.
The truck and its problem has been the main focus (maybe preoccupation) while in Shiraz but it has not been the only activity. While being driven around by Mr H we have had an opportunity to see briefly a wide section of the life of Shiraz. It is particularly interesting to see how street activity seems to start slowly during the morning and ramp up and continue late into the evening.
Our hotel is right in the center of Shiraz and this has given Nina a chance to visit a number of nearby clothing stores selling head covering garments for Iranian women. She is in the process of accummulating a sizeable collection of these things. Some of her collected items look very nice, others are a bit comical. When photos can be uploaded I will include some of Nina trying on these garments.