While trying to figure out the cause of harmonic vibrations in my 66 C-10, I had a conversation with a very elderly gentleman who once owned a GM dealership in Texas. He sold the dealership about 20 years ago. He told me of a chart he had (somewhere) that helped locate noise and vibrations in cars and trucks. Well, today he called and said he had found it and had a copy for me. The copy is so bad it's almost unreadable and can not be attached to this. It's titled "Diagnostic Chart Noise & Vibration" and on the bottom right corner it has: Motor Service June 1982 33. I searched Google with no luck. This chart is amazing as it shows speed ranges and lists noise and vibration associated with many different components at different speeds. I hope for the benefit of forum members that someone can find this chart and post a readable copy for all our benefit. And, by the way, it listed "Universal Joint Angles Incorrect" at the very speeds my harmonics surfaced.
All I have is a 60 Percent blackened 8 1/2 x 11...I think it was originally page 33 in Motor Service, June 82 ...whatever that is.
Hey John...I just spoke to the fella that gave me the chart (page) and he said that was a magazine that lots of dealerships and independent garages subscribed to. By the way, he retired in 1984. His copy is bad too.
Despite the poor quality of the chart, I decided to attach it anyway. At least you can see some of the info and note how valuable it is. Maybe this will help search it out on the internet.
Interesting....... With your help I think I can replicate the chart... I'll take a stab at it when I get some free time.
Here ya go.. let me know if something needs changed. The only word I couldn't read on the scanned copy was: UNIVERSAL JOINTS ???????? OR GALLED DUE TO HIGH LOADS OR IMPROPER LUBRICATION I simply used the word damaged... but that's not what the original chart used? Update: Changed "Damaged" to "Brinelled"
That's a fantastic restoration. I think the word you couldn't make out might be channelled. But, damaged works well too. Thanks a lot for the work on this. I think it's a slick diagnostic tool.
With my magnifying glass, the computer screen light, and a cold beer I revisited the mystery word. It's BRINNELLED!
Excellent... Brinelling Brinelling is when needle marks appear on the surface of the U-joint cross, which is usually caused by excessive torque, driveline angle. It can also be caused by a seized slip yoke or by a sprung or bent yoke
Darn it..those beer goggles caused me to see a double N! Same goggles that caused me to misalign the driveshaft
Brinelling Also occurs in any roller bearing when it's run dry or seriously over loaded , pounded etc.
