Spark plugs: finger tight, + 1/4 turn
At last count I have 13 torque wrenches, between the home shop & work shop, from the first one (Craftsman 1/2 click type) given to me by my step dad for Christmas at age 16 to a 1/2 dial type for pre-load settings. I have a 3/8 Snap On Tech wrench that I like a lot. As noted in a previous post here, battery life was an issue until I started unscrewing the battery cap, now they last as they should. Except for the dial type, Armstrong from my Matco guy and the original Craftsman, all mine are Snap On. I have them checked and they are still spot on. I have two split beam wrenches that do wheel duty because backing down is not needed. I have two 1/4 for small stuff. They get used a lot. One had a lock ring failure and I had my Snap On rep send it in for repair. It was too old and they had no parts. After a quick phone call to Snap On to confirm they could not fix there tool, the following week my Snap On rep walked in with a new wrench ($260) and said thanks for the business. There was no charge. I had to call because he had only been a dealer for a couple months and had to have a higher up make the call. Bottom line, you buy great stuff and it is your for a long time. My son will use these tools after I am gone, he does now, they just stay at my house.
That is how I torque the centerlock wheels on my TR, Breaker bar marked with my weight on handle. Make sure taper seating is clean.
Vince, Let me do your engine out service next time, totally on those Harbor Fright torque wrenches, OK? You will rest easy knowing that I torque your crank pulley bolt to 235 Nm, your cam bolts to 98Nm, your CV bolts to 78Nm, your suspension bolts to 80Nm, your engine mounts to 120 Nm, and your cam caps to 10Nm all on those $22 wrenches.
Get a Snap-On torque wrench of applicable range and you're done. I work in aviation and we have Snap-On brand torque wrenches over 30 years old. Mind you they are all sent out for calibration once a year to be re-certified. Why even bother cheaping out on torque wrench ? Amortised over 30 years buying quality becomes very affordable!
Use a torque wrench after using your method, see what you get. I used to do your way (actually), I would tighten with a wrench until the washer started to "yield" or crush), then go about 1/4 turn. I used a torque wrench to see how far off I was....a lot. I could go another 1 to 1 and 1/2 turns to reach correct tightness. I see occasional reports on BMW forums I visit ,of plugs backing out from your technique.
The BMW spark plugs do need to be in there tight, right up to spec or they back out and start "ticking" like a valve lifters.
Torque wrenches are measuring devices, and metrology is generally the last place to cheap out. Between calibrations one has to trust the instrument.
These are now my go-to wrenches. Hope to last for life. I got everything covered from 5Nm to 250ft-lbs and angle. One electronic Gearwrench, 2 split beam Snapons, 1split beam Precision Instruments, and a 1/4 inch Husky clicker. Everyone has been checked with a Torque meter to be accurate 2-4%. Image Unavailable, Please Login
LOL Interesting you say this. Happened to me once from a dealer service and one of those things sawed its way through the threads. Needed a helicoil that cracked the head. But that's another story.
