This is the fourth in a six-part series about Fleet Overhaul, the vehicle maintenance centre down at Burnaby Transit Centre. (Check out the first article on the body shop, the second about panel fabrication, and the third about the paint shop.)

Did you know we completely rebuild engines and transmissions for our conventional vehicles at Fleet Overhaul?

It’s true. Most engines are rebuilt for any conventional or articulated bus that has clocked 800,000 to 900,000 kilometres—it’s the central part of a high-mileage overhaul.

And transmissions are built and replaced in vehicles more frequently, usually when a vehicle hits 350,000 kilometres.

The high-mileage overhaul

In the two photos above, you can see the row of high-mileage buses being overhauled.

How do we fix them up? Well, first, mechanics at Fleet Overhaul completely rebuild the engine until they’re good as new.

While the engine is out, the back end of the bus gets a steam cleaning, reinforcement of its rails and structure, and a paint job. A licensed electrician also does rewiring and replacement of electrical parts.

After the engine is rebuilt and replaced into the vehicle, Fleet Overhaul staff then take the bus out for test drives to ensure everything’s in proper working order.

It takes about three weeks to overhaul a high-mileage vehicle. After this, Fleet Overhaul won’t usually see the vehicle again for engine work for another six or seven years.

Each year, Fleet Overhaul completes work on about 90 high-mileage vehicles. In 2008, the staff managed to overhaul 160 buses, as a small afternoon shift was added to help prepare for Olympic transportation demand.

Engine work

There are eight mechanics who build engines full time, and each engine is built by just one of these eight mechanics.

The mechanic’s name is then attached to each engine when entered into inventory, and there’s a definite pride in workmanship that comes with that. As overhaul manager Jeff Dow explains, each mechanic is very conscientious about the engine he or she produces, and feels quite personally responsible if an engine fails for any reason.

It takes about three and a half weeks to rebuild an engine, and Jeff says that 108 engines are built in an average year. In 2008, 120 engines were built, again in preparation for Olympic demand. (Due to cost savings, some engines are also bought new.)

Once an engine is rebuilt, it is tested extensively in a Dyno, a testing facility that runs the engine through its paces and can reveal any possible issues. A computer simulates the terrain that the engine might face in the real world, such as a run down Hastings or up the hill to SFU, which is considered the most difficult terrain of all.

Once the engine has been fully tested, it is painted one of four colours – red, yellow, dark blue, and light blue. The colours help identify the type of bus it goes into, the parts needed for the engine, and the engine’s emission package. (An emission package dictates what internal components are used to build an engine. Regulations are always increasing so a different engine was built in 1996 versus 2000, as the regulations are more strict.)

Transmission work

Transmissions are also built by mechanics at Fleet Overhaul. (A transmission takes the power generated by the engine and uses it to drive the vehicle’s wheels.)

There are eight mechanics who build 220 transmissions every year. It takes less time to build a transmission, roughly 50 hours. But as I mentioned before, transmissions are replaced more often, usually around when vehicles have driven 350,000 km.

Transmissions are also sent through their own Dyno for testing, simulating the regional terrain including the hill up to SFU again. Jeff explained that coming down the hill with a full load of passengers can be very hard on a transmission!

All right, that’s it for the high-mileage vehicles! Watch for the next installment in this series, which will be about the warehouse and the vehicle parts that get created at Fleet Overhaul.