In-Chassis rebuilds on older engines; we always try to do an in-chassis rebuild vs. an out of chassis because of the time element and the added expense. However, this past week two Caterpillar engines came into our shop for in-chassis rebuilds, and during the disassembly of the engines the main bearing caps fell out of the engine block. The main bearing caps are an interference fit and should be snug in the block. When they are loose the engine must be removed from the truck, completely disassembled, and the block and crankshaft must be sent to the machine shop. Sometimes a new main bearing cap is machined and fitted to the block, other times a small bead of weld is applied to the main bearing cap, then machined to once again be snug in the engine block. Once all of the bearing caps are tight, the crankshaft bore is then machined and the deck surface of the block is also machined. Next, the crankshaft is magnafluxed, straightened, and polished. Once the crankshaft is placed in the new main bearings, main bearing caps tightened to the proper torque, a man can turn the 400 pound crankshaft with one hand. At that point you know the machine work was properly performed.
There is another way to tell if the line bore in the block is OK without removing the engine from the chassis, and that is by a visual inspection of the bottom half of the main bearings. The wear across the bearing should be equal on both sides. If copper and the majority of the wear is on one side of the bearing than the line bore is out and the block must be removed from the truck and sent off to a good machine shop. The positive outcome is the Owner-Operator ends up with a great engine, maybe even better than when it was new. Unfortunately, the cost increases by about $12,000. A Signature rebuild on a Caterpillar 3406-E or C-15 with all of the performance parts we have to offer is about $38,000 plus the labor to remove and replace the engine back into the truck. Once the engine is out, now is the time to replace cab mounts, fuel lines, air lines, and brake lines. Total cost for all of the parts and labor can reach $45,000. The fuel mileage improvement over a stock engine will be 1.5 miles per gallon, which in turn will pay for the rebuild in about 2.5 years. It pays to have great credit, set aside 10 cents per mile into a maintenance account, have high limits on a few credit cards, or be good friends with your banker. The cost of parts and labor increases each year, I sure hope your freight rates do also.
Written by: Bruce Mallinson
Tires slinging mud and smoke, engines spinning at their limits, stacks spewing great black clouds of dust and flames, and massive crowds cheering, the first ever Onaway Speedway Great Lakes Big Rig Challenge was a success. The event included a Quebec style drag race and a show n’ shine for the trailer queens. The freshly built track was an 1/8th mile uphill run. Driver’s would be pulling over 60,000 pounds of lumber up the incline to the finish. It’s safe to say most of the spectators and participants had a marvelous time despite some difficult conditions.
The weather was quite a challenge. A cold front Saturday brought with it a heavy downpour for most of the day turning the grounds into a muddy mess. This not only made it difficult for the fans having to trudge through the soupy mess, but the drivers had to navigate a thick muddy pit in order to access the drag strip. Thankfully, Sunday brought the sun and warmth, but mud was still causing traction issues for the drivers. The only solution was massive 8 wheel burnouts to clean off the tires (to the delight of the spectators)
It was fascinating to see a range of different setups competing together on the track. The engine of choice for most participants would be the CAT 6NZ or similar while there were a healthy number of Detroit power plants, both 12.7 and 14 liter. Most of the drivers were running our performance parts on their trucks. Class C trucks were bone stock while the majority of participants were running in class B which allowed minor modifications including a non-stock turbo and Powerbox. Class A contenders were highly modified with turbos peeking through grills and hoods.
Running these trucks at their physical limits means quite a few trucks suffered from mechanical complications. A number of trucks broke driveshafts and U-Joints including Diesel Freak’s white and blue Kenworth. Fortunately, they were able to get the truck fixed for the next day white others were not as lucky. Khaggs Trucking #100 Freightliner suffered from power loss to the ECM on Sunday, ending their day early. The majority of trucks were able to return home under their own power.
In addition to the racing, there was a healthy showing of show trucks on the track oval. Everything from a ‘bagged’ Peterbilt, vintage Kenworths, and even a Smokey and the Bandit tribute truck complete with the stagecoach mural on the trailer. The youngsters enjoyed the carnival rides while the racing fans learned about the cutting edge of truck performance technology from the vendors in the pitts. Many came to look at the display engines and learn about our innovations such as the Dorothy EGR cleaner and see our selection of performance oriented exhaust manifolds, mufflers, and turbos. We look forward to the return of the Great Lakes Big Rig Challenge in 2019 and hope to see similar events around the US in the coming years.
Many of the articles compiled here where written by Bruce Mallinson. Attribution to other contributors is given in the specific articles.