SERVICE....
SERVICE....
There comes a time in every Mog's career when you must have some service work done. Helmut has been in service since 1970, and over those 35+ years I'm sure has seen more of the world than I have. I try to do some service, and most of the maintenance, myself but sometimes you must break down and seek help of the professional sort. In my experience Unimogs, at least the Diesel variety, are expensive to repair and maintain. Most parts are available through Mercedes-Benz dealers and a select group of Unimog parts distributors, but costs can add up quickly in price and in downtime for the machine. Being 35 years old I expected that Helmut would need some TLC, below are some pictures of the carnage, as well as some history behind it......
PHASE ONE:
Helmut was delivered to me with approx. 44,000km on the dial, and about 3500 engine hours. Not bad, but the maintenance of the machine was obviously lacking. I think I was burning and leaking more oil than fuel so the first job was to do some engine diagnostics. It was determined that I was in need of a new engine gasket kit, a new head, clutch, and various other items were taken care of as well. Mike at Miklyn Mobile in Orillia, Ontario took care of the work for me. It was a long summer with Helmut laid up, but the results from the shop were good, and I hit the trails in September.
PHASE TWO:
Helmut went back into the shop the next year for some axle work. The old drum brake pads were renewed, the front and rear wheel bearings and wear rings replaced, a new front DS axle fitted, and a new starter motor. The gears in the DS front hub were replaced as well due to contamination from leaking seals and years of abuse. A new factory fuel tank replaced the old beat up "custom" one, and some fuel lines and hoses were replaced as well. It was back to Miklyn Mobile for the winter.......
PHASE THREE:
Helmut is currently serving time at Currie Truck Centre in Alliston, Ontario. Last fall the motor decided it had run its course and started to consume oil at a rate of about 7 litres per 300km. I was literally using more oil than diesel fuel, and oil pressure was not even registering on the gauge. I knew it was time when I pulled out onto the road and looked over my shoulder to see a plume of smoke concealing the car and basically everything behind me. One thing I learned from all this, which I have learned again and again, is that you can't get away with doing things half-ass. The motor should have been rebuilt or replaced back when I had it on the engine stand before. It is one of those things though, who knew what could happen two years down the road. A compression test revealed damaged ring seals, and upon inspection of the block, major wear was found. I can only surmise my engine had a lot more than 3500hrs on it. The bright side is a new engine, and many new parts to accompany it. When Helmut returns to service this summer, he will be better than ever. Many thanks to Robbie and Hans at MROSS Import Service, and Trevor, Dean, and the guy's at Currie Truck Centre in Alliston.
The new engine arrives from MROSS Imports.....
The new engine gets lowered into the chassis, the new springs (HD) are installed and the cab is now ready to be lowered onto the chassis.....
The cab gets lowered back into place and the Mog is almost ready to hit the road again.....
Opps, after a slight clutch problem on installation of the motor, the transmission needed to be removed. While she was out on the floor, I decided it was a good time to "fix" some old trans. problems with a newer rebuilt unit. So, after removing the PTO (I don't use it) the trans. was cleaned, painted and is ready to be installed back into the chassis. Notice the way the trans. was removed from the donor truck...... That's Mike from Miklyn Mobile working the crane in the old Mog. The nice shiny part on the motor is the electric engine coolant heater that I am installing.
Well, the Mog is on the road again after its transplant and is running extremely well. Many thanks go out to Dean, Trevor, and everyone else at Currie Truck Centre in Alliston for all the work they did. I think Dean now qualifies as a factory Mog mechanic.
REAR AXLE SEAL REPLACEMENT 2006:
After last month's trip to Coldwater, Helmut decided it was time to replace the DS rear outer axle seal as evidenced by the oily mess leaking down inside my tire and all over the drive-way. It was a fairly simple job, of course having all the right tools (ie. large tools) helps. One of the best parts of doing work on Helmut is my growing number of tools in the shop.
You can see below the leaking seal ring. After removing the hub, and the castle nut holding the wear ring on, you can see the bearing and shim that rides inside the portal. I pried out the old seal, cleaned and flushed the hub with oil, and tapped the new one in with a soft mallet. I then cleaned and re-installed the wear-ring, hub, and brake drum. Lets hope it lasts a while.
MICHELIN XM-47 TIRES 2006:
Helmut decided it was time for some new tires one day when one of the old XM-27's decided to slip a belt in the sidewall. The bulge was so bad that it extended all the way down to the bead thus letting air escape from the tire. It turns out that Michelin no longer makes the XM-27 in the high speed version (55mph) so it was time to search for some new rubber. Well, I actually knew long ago that I wanted to replace them with the XM-47 version of the same tire. This tire is "G" rated for 55mph, and has a deeper lug than the 27's - best of all they are 2" taller and 2" wider. The current 27's are 335/80/20 or the equivalent of 12.5X20's and the new tires are 405/70/20 or the 14.5X20 equivalent. As you can see they aren't much taller, (of course that comparison photo has the weight of the truck on them) but noticeably wider. I think the 14.5's make the Mog look more balanced, and the tractor tread is perfect for the Canadian wilderness.
As you can see from the photos above, the 27's were much more "flat" against the rim while the 47's "round" out more away, which should help to protect the rim and keep mud and debris from jamming into the bead.
My first impressions of the 47's off-road is that they are very similar to the 27's, although the steering feels more "heavy" probably due to the increased weight and width of the new tires. On the highway they ride the same but allow me to cruise at 80 km/h at only 2600rpm which is a nice compromise between speed, noise, and heat related issues.