Dan Fletcher Super Stock Videos - Opinions

[69Cobra]

Sounds like the ring and pinion to me.

[Lee Jordan (3223) A/S]

Originally Posted by Larry Hill

Might want to look at the tail shaft bushing. Just a thought.

I have had issues like this before and it wasnt the tailshaft bushing, it was the slip yoke on the output shaft. Over time it got loose and would only vibrate on deceleration, and would only be at a certain speed. I wouldnt rule out the gear either.

[Pat Cook]

I had the same noise on my Fairlane that ended up being the driveshaft. I changed gear ratios from a 4.86 to a 5.14 and it moved the 59" long drive shaft into the critical speed. I had the original shaft balanced and checked twice at different shops, had another shaft built out lighter and larger material, Replaced several tail shaft bushing ( the vibrations was eating them up} removed the tranny and replace all the bushings, new yoke, had the rear end apart, looked at axle bearings...was getting very frustrated. Finally, there was a NASCAR team doing some testing at the Proving grounds were I worked and I ask them who built there drive shafts, They told me about a shop in Michingan, Dynotech Drive shafts, Called them, the guy I talked too guaranteed that he could build me drive shaft that wouldn't vibrate, and he did.
Mark Williams has a good tech article on drive shafts and critical speed
http://www.markwilliams.com/driveshafttech.aspx

[Brian Oakes]

Hey Dan, i think ya get spoiled driving that new car, ya know all them old ones will Vibrate,LOL hope ya fine the problem, let us know what it is. Later Brian

[Dan Fletcher]

I appreciate everyone's input, both here, pm's, and phone contact. Lots of good thoughts. I especially like accelerometer notion and the idea of a chassis dyno.

At this point, there won't be any empirical testing done until Las Vegas. As hard as it is to believe, I've chosen NOT to drive 1200 effin' miles, one way, to Gainesville to finish Charlotte. Stick that whole deal right up your ***. I could maybe get out locally this weekend or next, but my wife and I have scheduled trips to watch our daughter play soccer and I'm not going to screw that up.

So, it will have a different center (read ring and pinion) in it at Vegas. If that doesn't fix it, its going to be time to instrument things up and find a chassis dyno, or start looking for loose sheet metal. If I don't find it soon, I'm afraid it's going to find me.

Good luck to everyone in Gainesville, especially Joe Lisa, lmao.

[HR1140]

There is one unusual thing that i've seen cause vibrations like this twice now on a 69 nova, and a 79 camaro. The nova was chasing a vibration like this all season and ended up doing most of the things you are. It turned out to be a worn out bushing in the steering box.

The other was on a friends camaro that he has been dealing with most of the season. We have checked and replaced parts in the driveline, and rebuilt the transmission with no luck. When I had the car jacked up I remembered the issue with the nova so sure enough the idler arm was so worn it was ready to fall off. We haven't tryed it yet to see if that fixed it.
I would doubt your issue is there, but is is worth a look...

[Dan Fletcher]

Well, I don't profess to be the sharpest tool in the shed, and my day to day actions fully support that position. I said my next move was to physically remove the 4 link bars and carefully inspect every rod end. I haven't done that yet, we're a little too busy around here taking advantage of the nice weather to get the compound winterized.

However, a buddy stopped by a little bit ago, and I was showing him the videos. Make the one taken from under the car full screen, but ignore the u-joint and stare at the lower rod end that's in view.

Like I say, I'm no genius, but I think we may have found the source of the problem. This might be the 2nd car I've been lucky to not destroy this year.

[Robert Simpson]

Does it look like it is pulling away from the 4 link bracket? The picture I have is small. But, that is in coast mode also so the bar would be in tension not compression. I hope you found it. Please let us know when you do.

[dannyboy]

Very clear once you focus on that. Saved a disaster and possibly personnel injury with your friend observation. Sounds like 4 new Heim ends or going to be installed.


Dan Chipman

[tim worner]

Just looked at what you said and it sure looks like you found it. Now you won't have to replace the windshield.