3rd gear knock cause found (with videos)

[Kevin - Illinois]

I promised a while back I would post the info on the source of a 3rd gear knock. Sorry it too so long but here are the videos starting with the original of the knock. Thank you everyone for your advice and patience throughout this ordeal.

Original Knock:
https://www.youtube.com/watch?v=VMb7d...ature=youtu.be

Rear End Out:
https://www.youtube.com/watch?v=kYglW9ZSX-k&feature=plcp

Source Found:
https://www.youtube.com/watch?v=M_8IEU1ghM0&feature=plcp

[Ed Saniewski]

Thanks for the great info. but why would the noise only be heard in third gear?

[Wick]

To just break 2 teeth,something...nut,washer got between the two teeth and took that chunk out?
Nice video!
Wick

[1931 flamingo]

Thanks for posting the videos again. I know it was a long journey that generated a lot of interest here on the Barn.

Paul in CT

[newshirt]

Wow! Nice documentation. Thank you for a great explanation of the "transmission" knock. Very informative!

[Farrell In Vancouver]

Sponsored Links (Register now to hide all advertisements)

Wow Kevin! Quite the journey. I thought you had put up a video of the engine running sans transmission and still had the knock?
I am glad you found the culprit and thanks for sharing your solve. This speaks to your patience, I can think of a few guys that would have walked away and sold it.
Cheers!

[Patrick L.]

Did you recently have the differential apart ?? It kinda sounds/seems as though it was.. It may have been the camera angle or some such thing,, but,, the patterns looked kinda funky.. Thats a heck of a place to find a transmitter knock.. At least,, now thats its found and apart,, its a fairly easy fix..

[Russ/40]

Thanks for getting back to us Kevin. You are very right to be appreciative of the work the engine builder did to help you out. I am humbled by my eagerness to expect more from the builder, and am smarter and a bit more cautious to point fingers than perhaps I was before. He did right and then some for you. A testament to his good business acumen.
I was so sure in the beginning that it was the cluster, as they knock just like your ring gear. An amazing case of a deceptive coincidence.

[bogdonj]

Thanks but I agree why would third gear only make the noise?

[columbiA]

Likely because the ring & pinion are turning a lot faster in 3rd than in other gears.

[Kevin - Illinois]

I was thinking it was because in 3rd gear the rear end has the most load.

[Tom Wesenberg]

Originally Posted by Kevin - Illinois

I was thinking it was because in 3rd gear the rear end has the most load.

That's probably true while the rear is up on jack stands, but while driving on the road first gear can apply the most torque to the rear end.

I thought the rear was out when one of the videos with the noise was shot?

[TinCup]

Thanks for the follow up. This forum is not just for posting problems its also for posting solutions. Great job with the latter.

[H. L. Chauvin]

Kevin,

Had you gone to school to become a mechanic, you may be tearing down both engine & transmission for the thousanth time reading & searching for a school book solution.

You are definitely gifted with rare Common Sense to be able to diagnose problems without the help of others or books, by simply concentrating & listening to your own inner thoughts.

With today's methods of formal education, learning is at such a slow, ridiculous pace as compared to a few years back when students were challenged to "think" for themselves.

Read some time ago that if one successfully finished high school before 1958, one has the equivalent of a bachelor's degree in the year 2000 & beyond.

Congradulations to you & you wife for such a wonderful achievement!

[Brentwood Bob]

Thanks for closing the circle. Those rear ends are stout. Remarkable. Bob

[Brentwood Bob]

A lot can be said for the junior high, and high school shop classes that were then available.
We got exposure to great instruction, and hands on learning. Non-existent for the most part now. Bob

[van Dyck]

I have a quick change rear end in my roadster. At highway speeds the whine sound appears to be coming from the front, not the rear as would be expected. Sounds will telegraph to different areas.
BTW, "thinking", diagnostic mechanics are getting to be fewer and farther between! You can lead a student to knowledge, but you can't make him think.

[Christoph]

Interesting one - Thank you

My pinion looked nearly identic and it did ALLWAYS bad noises
once car was rolling

AND IM THANKFULL THAT I DIDNT HAVE YOUR PROBS TO FIND OUT ABOUT

Thanks for sharing
Christoph

[Kevin - Illinois]

Shop classes are helpful, but a lot can be said for being raised on a farm in Michigan too. When things broke we had to fix them. This one I must say was a real bugger though.

[Terry,NJ]

Thanks for posting!
Terry