Surfer69

I had bad rattle at high rpm around 75 to 80 mph that I was chasing and could never figure it out. Tried shimming, drive shaft, tires all the things we discussed in the past. Turns out it was bad motor mount on one side. You would never have been able to tell mount was bad by inspection. Only in your hand when you push two halfs together, if they touch you know its bad. No obvious cracks or anything.

My rebuild with 262 cam is running great and now no rattling. It's such a good feeling when everything is working right! :yesnod:


[Modified by Surfer69, 8:35 AM 8/12/2003]


[Modified by Surfer69, 8:44 AM 8/12/2003]

wcsinx

I have the exact same thing. I can feel it in the column too, but the worst of the noise comes through the shifter. I'd assumed it was either my mounts or balancer. Good to know that new mounts took care of it for you.

Burgundy 69

I have had the same problem with my 69 350 (with a Hurst shifter). Once I hit about 2500 RPM the shifter rattles loudly. Interestingly, I found that the noise seemed to be coming from the plastic ball vibrating, so I take it off when I hit the highway. This quiets things down a bit but is not an acceptable alternative. For those with the same set up, you know there is a nut below the ball which helps orient the ball shift pattern. This past weekend I decided to replace the old nut with a new shiny one. As it turned out, the new nut has a wider diameter than the old nut and when I screwed the ball down, it seemed to catch and hold the ball in place better. When I drove my car, the vibration disappeared. This 10 cent fix has given me great joy!

Mark

wcsinx

Did you intentionally misspell your handle, "Burgandy 69"?

Burgundy 69

No, actually I am just a lousy speller. I have attempted to change my profile several times but have been unable to figure it out. I came to the conclusion that I may have to create a new account so I gave up trying. Any suggestions??

Mark

wcsinx

I know it can be done. You probably have to talk to a mod though.

ddecart

:yesnod: Lemme know what you want it to be. Burgundy?

Cool on the shifter rattle. I have the same thing. Maybe I need to check those motor mounts. I'll do that AFTER I get a new driveshaft.

red topless gator

nteresting, mine rattles on the highway, but if I hold it or push down a little it will stop until I let go. Could this be the same thing? :confused: LT

Petes73

Go to help forum and request a new name

tshort

OMG!!! I think if you were near me when I just read this post you would have literally seen a lightbulb light above my head.
On my old engine I had a bad vibration too. It was RPM specific in that it got bad at the top of each gear. On the highway sometimes it got so bad that it would shift the car out of gear. I had the rearmost bearing replaced in the transmission and for a while the vibration went away. But it came back shortly after and I attributed it to the engine. My harmonic balancer had twisted severly and was in bad need of replacement. I had all but forgotten about this and I am seeing vibrations again in the new engine. It is also RPM dependent. But I replaced all my motor mounts with Poly's.

Does anyone think it could be the frame? A crack or something? I visually inspected it when the engine was out and couldn't see anything.

But then again, with this much torque, I think if it was a crack it would have ripped the whole frame engine mount off by now. Aaaaggghhh, problems problems problems. :mad