- Buyer's Guide
In this issue of Machinery Lubrication, we are going to talk about gears. We are not going to introduce another article with an aviation reference. The gear up or gear down referred to here is not the landing gear on my old plane. Nor do the gear up and gear down indicator lights on my computer flight simulator introduce another article on gauges.
I never paid much attention to gear lubrication before signing on with Machinery Lubrication. In the automotive world, most of the gears I see are lubricated by engine oil. The timing chain gears, distributor drive gears, and even the oil pump gears are all bathed in engine oil. The transmission and differential gears are also in a constant oil bath and require special lubricant formulations. The starter drive gear, mating with the flywheel, is exposed to hot air, mud, dirt, rain and snow, and not lubricated at all! Yet it lasts for years. Consider chains for other uses: bicycle chain and gears (sprockets) need regular manual lubrication. Motorcyclists manually lubricate their chains. There is a chain and gear oiler on a chainsaw.
The gears and chains not lubricated by a constant engine oil bath seem to have an acceptable lifespan. The gears and chains in the car motors I work on, however, are always oiled while they are working. They should have an indefinite life span. But why don’t they?
Timing Chain Problems
I just disassembled the upper engine of a 1996 Lincoln town car, 150,000 miles, with a 4.6L V-8, single overhead cam (one on each head). The car was towed in, and the described symptom was that it had suddenly stopped while driving at 45 mph. The car backfired when trying to restart it. The computer scan showed nothing basically wrong. It had fire; the fuel supply and the injection system were working. Upon checking compression on four cylinders, I found three with little or no compression, and figured something was amiss with the timing chain. That diagnosis was a surprise to me.
Several of my customers with this same engine have already reached more than 200,000 miles and have experienced no timing chain problems. Initially this wasn’t predicted, because the engine has a complicated chain, gear and chain tensioner setup. When the motor was first introduced in 1992, I expected a lot of future business because of its complexity. I was wrong; the Ford 4.6L engine has proven to be a reliable and trouble-free setup.
As I began disassembling the engine, I found a big surprise: several rocker arms (more accurately cam followers) had been flung off their mounts and were no longer opening and closing the valves on their respective cylinders. These misplaced rockers could cause backfiring and the failure-to-start condition. Cylinders either had no air going into or out of them, and some had rockers missing. The chain was intact, but apparently loose. The looseness was because of tensioner, chain and gear wear. The reason was evident in the fine gritty paste of sludge, made of dirt and waxy oil residue, which coated the insides of the rocker and timing chain covers. Some of the grit entered the engine via the cracked PCV hose. (See “A Breath of Fresh Air” Machinery Lubrication, September-October 2001.) The customer, not one of my regulars, had foolishly neglected changing oil in his engine. A complex engine like this one would have benefited from regular oil and filter changes, perhaps more than most. I was looking at a classic case of, “pay me now or pay me a whole lot more later”. The $750 dollars he’d saved, (based on $25 per change every 5,000 miles) was now going to cost him $3,500 for a remanufactured long block and labor. Plus the car will be out of commission for almost a week.
Why do customers neglect these things? I think the answer lies in the lack of inspection. They cannot see the lubricated components. The very reliability of those components tends to lull one into a state of neglect. The misconception is that nothing mechanical has gone wrong for 100,000 miles, so nothing will go wrong today. I can see a bicycle chain, the gears on the derailleur, and the bearings in the wheel hub. However, I can see nothing on my car and I use it almost every day and it never breaks.
Education is the Answer
The better my customers understand the value of preventive maintenance, the money and time it can save, and the additional money from increased resale value, the more willing they will be to pay more for maintenance. Selling maintenance has become a focal point of my business these last few years. It has been a hard sell. With cars costing more than $25,000, it makes good sense to take care of them. But customers are leery of being sold anything that doesn’t produce immediate satisfaction. To them, I appear to be padding my already full pockets because they remember how much it cost the last time they visited me for a repair.
Let me say this, and please believe me I don’t know of a single mechanic who doesn’t enjoy repairing a well-maintained car. He will do a better job, putting forth a little extra effort on a car owned by someone who takes pride in, and takes care of his car. I catch myself working on a “raggedy” car - one not well maintained - wondering what’s the use of my labor? It takes self-discipline to offer the same level of service to everyone. There’s no excuse for providing professionalism on a sliding scale, but it happens. Old cars offer little excuse to neglect maintenance. I have a customer with a 1969 Buick Electra two-door hardtop. I love to work on the car because it has been so well maintained. The owner is in his senior years and he knows it will be the last car he drives, but he takes care of it like he will be driving it another 30 years. I hope he does.
The readers of this magazine are preventive maintenance specialists. So I recommend Jim Fitch’s related article “Dipstick Oil Analysis” (Practicing Oil Analysis magazine, November-December 2003). It’s the best article on how to find out what is going on in your engine.
I imagine that readers, as professional maintenance specialists, have the same challenges I do in selling preventive maintenance. I sell my programs to customers; you have management and budget people to convince. We must sell an idea … that most intangible of things … the ideas we know will save the company or customers money in the long run.
The other gears on your car that need lubrication, the differential and manual transmission gears, all have maintenance schedules. Even though maintenance on these items is typically needed only at high-mileage intervals, they should be serviced when called for. Any good repair shop can print out a maintenance schedule designed for your car. Listen to your mechanic’s advice, for maintenance schedules can be influenced by local conditions and driving habits. Just like you, we strive to be professional. Please listen a little, for we have your best interests in mind.