For those who have an interest, this is the story about the Triumph TR6 solid alloy crankshaft thrust washer development.
Page One - August 1997
After doing some serious searching, I located a car for sale that I had always wanted to own. It was a very well cared for 1976 Triumph TR6 with around 38,000 accumulated miles. I found this car advertised within The Vintage Triumph Registry website classified ad section. After corresponding with the owner to learn more about it, I decided to drive the 300+ miles to Kentucky to take a better look at the car.
Upon arrival, I spent time thoroughly inspecting the car inside and out, and was very happy with its overall condition. The car appeared to be very original and well cared for. Overall, the car fit the owners description, and I felt my trip had been worth the drive.
The odometer displayed around 38,000 original miles, and this seemed believable after observing the overall condition of the car. Of course, there are drawbacks when buying a twenty-two year old car with low miles. Certain parts naturally age over time whether the car has been driven or not. These items include coolant hoses, fan belts, tires, plug wires, and hydraulic seals that can dry out and crack when not used. But I felt those disadvantages could be easily dealt with one by one once I got the car home.
Once I had finished inspecting the car, it was time to take it for a test drive. The owner had told me the starter had been giving him some trouble from time to time, and sure enough when we tried to start the car, it wouldn't respond to the turn of the key. The owner got out of the car and opened up the boot (trunk) to remove a small ball peen hammer. He then opened the bonnet (hood) and told me to tap on the starter with the hammer while he turned the ignition key. Many buyers might walk away at this point, but since I had my share of experience with Lucas electrics, this didn't seem to be at all out of the ordinary to me. Sure enough, the starter responded to my whacking of the hammer, and the engine started right up. I knew the starter was a simple fix, so I proceeded with the test drive.
When the car started, I glanced at the tail pipe and didn't notice any blue smoke that might indicate a problem. The engine idled smoothly and quietly, with the unmistakable sound that so many TR6 fans have fallen in love with over the years. I got into the drivers seat, and could tell right away that this car was a good fit for me. Upon take-off the car responded exactly as it should, and after shifting through the gears I could tell that it seemed reasonably tight and had a very nice throttle response. The overdrive operated flawlessly, and the rear end didn't have any clunking that would indicate worn u-joints. When pressing on the brakes, the car came to a quiet, straight stop. Other than a few rock chips on the paint, older tires that would need replacing, and the need for some minor refurbishing overall, I knew this car and I could become fast friends. After the usual haggling, I paid my bill and loaded my prized possession onto the trailer and headed for home.
The drive home was enjoyable because I was happy to be pulling a trailer loaded with my new Triumph. I took every opportunity to take a glance at the car in my rear view mirror, and couldn't wait to drive it. After a long day of driving, I finally arrived at home. My family had been patiently awaiting to see what I would be bringing home, and they all came out of the house to take a look at the car I had been talking about so much. They were all very happy to see a complete car on the trailer. Many of the British cars I've dragged home have been questionable, sometimes unrecognizable, and came with a lot of boxes to unpack.
After all of the hoopla, I hopped into the drivers seat so I could start the car and show it off to my family while backing it off the trailer. I turned the key, but it wouldn't start. I explained to the family that this was just a minor problem. I got out of the car and opened the boot to retrieve the ballpeen hammer that was now a handy accessory item. I showed my wife how to properly whack on the starter while I turned the ignition key. She gave me a look as though she was questioning my sanity, but she agreed to whack on the starter while I tried to start the car. Unfortunately, the hammer trick didn't work this time, and my wife gave me another look, and I decided to push the car into the garage and call it a day.
After a restful nights sleep, I went to the garage and removed the starter and took it to a local repair shop to have it rebuilt. A few days later, I brought the starter home from the repair shop and reinstalled it. I turned the key, and the car started right up. My thirteen-year-old daughter heard the sound of the car from inside the house and came running to the garage to get a better look. I told her to hop in, and we took it for a drive around the neighborhood.
While driving the car, I realized that I had forgotten my wallet that included my drivers license, so we returned home to retrieve it. I turned off the engine, and ran into the house to retrieve my wallet. When I returned to the car, I started the engine, pressed on the clutch pedal, and heard a loud grinding noise. I quickly removed my foot from the clutch pedal, and the noise went away. When I pressed on the clutch pedal again, the noise returned. After listening closely I decided the sound had to be coming from the bell housing area, and felt it must have something to do with the clutch. I spent the next few days removing the transmission to determine what needed to be done to correct the problem.
After carefully inspecting everything inside the bell housing, I couldn't find anything obviously wrong, but since I was already there, I decided to have the clutch rebuilt locally, new Borg & Beck pressure plate, double bushed the cross shaft hole and gooped with Anti-Seize, clutch fork upgrade, new throwout bearing, and make some other recommended improvements. After the job was complete, I started the car again and pressed on the clutch pedal. To my dismay, I heard the same grinding noise. It was obvious the noise was coming from somewhere else.
After doing some additional research, I learned about a potential problem with TR6 crankshaft thrust washers that is often overlooked with these cars. This little thrust washer plays an important role by keeping the crankshaft from moving in either axial direction, and keeps the crankshaft aligned with all of the other moving engine parts. Whenever the clutch pedal is pressed to the floor while shifting gears, the spinning crankshaft is forced against the rear thrust washer. When the two surfaces come in contact under heavy force, there is a great deal of friction, and this causes wear over time. Unfortunately, once the thin copper surface wears through to the bare thrust washer material, the steel crankshaft begins ginding away at the bare thrust washer surface, and rapid wear results. Thrust washers are intended to be replaced at regular intervals to keep this from happening, but this service interval is commonly ignored.
I performed a simple crankshaft end float check, and this determined that I had way too much movement, which indicated a problem. I drained the oil and removed the oil pan, and found both front and rear thrust washers laying in the bottom of the pan. The rear thrust washer had worn so badly that it became too thin to stay in its nesting place and fell out. Due to the excessive movement, the front thrust washer worked its way out of position as well. Now there were no thrust washers in position to keep the crankshaft in place whenever the clutch pedal was pressed. The crankshaft was now forced into the side of the bearing journal end cap, and the wear eventually progressed to the point that the flywheel teeth were able to come in contact with the starter gear, thus making the awful grinding noise.
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