Cocktails , shaken or ...

[Ragtop Man]

...Exploded ! So I have not seen a whole lot on the dampeners or cocktail shakers as some call them . I had to take my rear ones out a few months ago and decided to remove the plug . Seems no one really does this from what little I have heard on these boards . Well , the 9/16 plug was damned tight and could not be removed with a wrench so I put my harbor freight electric impact wrench on it as my ryobi battery impact drill wouldln't break it loose . I had the thing standing upright and blocked up and did not expect a black oil gusher effect to splash me in the face and with a fair amount of force So this caused me to fall backwards and knock the thing over where the oil also sprayed up against the wall of my garage . It also got all over the back and side of my car in droplet form . So after cleaning all of this up I left them alone for the last 3 months . I only drove the car occasionally , very little really , as I had some other things going on with it but I did notice that it had the same occasional shimmy as when the shakers were in . Well , I finally drained the one and flushed it with a little paint thinner and let me tell you the oil inside looked and smelled more like nasty gear lube and was pretty disgusting . I carefully took the plug out of the other one and it still sprayed some . I drained this one into a small coffee can which turned out to be a quart . I happened to have four quarts of various trans fluid collecting dust and used this to fill them . I cleaned them up and painted them and put them back in . And went for a drive . I've got to say it could be a placebo effect but damn it seemed to ride better and no shimmy on the bumpy road nearby at all . I ended up drilling a 1/8'' hole in each plug and running a small self tapping screw into the hole which I think will allow them to breathe just a bit . So I'm wondering if all of this pressure that was inside due to all of the engine heat caused them to not work corrrectly . As I said , when they were installed before all of this I would get the occasional shimmying . Today I removed the two in the front and they were not nearly as nasty since no engine heat but oil was still old and I cleaned them out too and put fresh trans fluid in . BTW , they also hissed for a while too but not as long . Yet to drive it since this procedure but will report back . I also have a pic to post and will later . If you decide to do this on your ragtop I suggest a good breaker bar if needed and then back the plug out with a wrench until it starts to hiss

[davemotohead]

I don't think you are supposed to take them apart? They are under pressure!

[Ragtop Man]

Thanks Dave , but I'm not sure why they would be pressurized when they are nearly full of oil . Also how would GM pressurize them when there is just the one plug ? I didn't think you could compress a liquid either which is why they make such good hydraulid fluid. I think they were full of pressure from 50 years of engine heat but I could be wrong .

[azdave]

They are not supposed to be pressurized and there would be no benefit to doing that. I've opened them before up to confirm that a PO did not drain them as they need fluid to operate as designed. I added the shakers back to my 66 vert and after that it shook way less than when they were missing. Mostly noticed the shaking on things like a railroad crossing.

Best guess is they were last opened under very cool conditions and you opened them when it was much warmer. Either that or something evil is growing inside and wanted to get out.

[Ragtop Man]

Thanks , It seems like there is almost zero interest in this topic After driving the car some more I am convinced that the rear ones were not working at all and perhaps just releasing the pressure would have helped them . But I'm a stickler for changing lubricants especially when they're 50 years old . I appreciate you sharing that info with me AZ I think maybe these pics give an idea of how pressurized the rear ones were . I'd say it was around 75 degrees when I did this and they were not hot . BTW that's a beautiful trunk

[bbodie52]

From

http://corvaircenter.com/phorum/read.ph ... 366,384498

Here is some interesting Q and A from a Camaro topic.
Seems they even had different part numbers between Camaro and firebird, and different numbers year to year!
And I still say, None of the Camaro/Firebird shakers are the same as Corvair.

Q. What are the canisters or dampeners in my convertible? Can I take these out and install something else? Also ... My convertible has a bad vibration while going down the road what could it be?

A. On the corners of convertibles there are what's called "cocktail shakers" or vibration dampeners which were originally installed on every first gen convertible Camaro to help prevent vibrations. They were installed due to a very flexible body in the convertible models because of the lack of the roof structure. Some reinforcement was added to the convertible rockers and floors but it wasn't enough to prevent all vibration problems. The cocktail shakers are large cans with a suspended mass on a spring in a viscous fluid that are mounted on the corners - 4 in all. They were tuned to a resonant frequency of the convertible that caused the vibration problems. When the body was subjected to loading that would otherwise tend to make it oscillate, much of the energy was instead absorbed by the motion of the masses in the cocktail shakers - which reduced the vibration in the convertible body. The cocktail shakers weight about 25 pounds each.

It certainly would be possible to add a large amount of structural stiffness (subframe connectors won't be anywhere near enough) to the mid-section of the body to reduce or eliminate the vibration to the point of being able to remove the cocktail shakers. However that possibility would be very remote without a complete understanding of the Camaros stress and flex points. Another option would be to design and build your own vibration dampener. That, however, would require knowledge of the structural frequencies of the Camaro convertible body not to mention knowledge of how to tune the damper you are creating. The cocktail shakers are filled with automatic transmission fluid or ATF. The fluid is not subjected to friction, high heat or contamination as is the case with other fluid applications in the vehicle so it should not "wear out". The springs would be the only thing that could change or break, that would keep them from working properly. We have never found a "bad" one, if it still has fluid in it, only cars missing them which have the common 'cowl shake' much worse than normal. If your convertible Camaro has all four cocktail shakers and you still have bad vibration problems be sure to check that your tires are balanced properly and also new OEM body bushings can help reduce some of the vibration transfer. Be sure to check your springs and shocks as well. You should also try adding subframe connectors to help with flex and vibrations

I think I could live happily in that trunk...

[Ragtop Man]

Thanks for that link Brad So it seems that the canisters from any other car could not work if they are harmonically tuned even if they did fit , not that I'm looking for any . So you have a ragtop . Have you ever considered opening yours up if you haven't already ? That first one I opened really knocked my socks off AZDave , you said you opened yours up and no bubbling crude a la the Beverly Hillbillies ? It's perplexing that no one else seems to have had this experience . This car has yet to be boring for the most part and sometimes I think it's been possessed by a disembodied female spirit

[Blue hen]

I think Ed China on "wheeler dealers" goes into some detail about the shakers. They are used on a renault to dampen the vibration. Renaults have lead wieghts with a central holes which allowed the oil to pass through .