RivNut Posted May 7, 2012 Share Posted May 7, 2012 Today I got a call from a mechanic up in Leavenworth, KS asking about a vibration in a customer's '63 Riviera. It's constant at about 2800 - 3000 rpm's whether the car is on the highway or being revved up in neutral. The customer bought the car just after the engine had been rebuilt. The mechanic swapped out some aluminum balancer for a correct 401 steel balancer thinking that might have been the problem. No change.My question is this. Is the dynaflow flexplate like the ST400 flexplate in that it has to be bolted to the crank hub in only one correct out of six possible ways to bolt it on? Anyone know anything more about balance/vibrations in nailheads w/ dynaflows?Thanks,Ed Link to comment Share on other sites More sharing options...
Snake Posted May 9, 2012 Share Posted May 9, 2012 I had just pulled my engine on a 425 Riviera same problem , to my suprise it was not intalled right. You can see where the hole matches up to the indent. Im still going to rebuild and balence it out for peace of mind. Link to comment Share on other sites More sharing options...
60FlatTop Posted May 12, 2012 Share Posted May 12, 2012 Ed, I hate to write this. The car could have a cracked piston. I know of a couple, mine and a friends. Things weren't quite right but they had to break to finally show up. Lots of stuff can be overlooked even during a rebuild.I will see if I can get a picture of mine today.Bernie Link to comment Share on other sites More sharing options...
60FlatTop Posted May 12, 2012 Share Posted May 12, 2012 About 12 years ago I put these pieces into a sandwich bag. I had been having a vibration and couldn't get the car tuned quite right.When the piston disintegrated the rod stayed in the bore and just tap danced up and down doing a great peining job to the walls. The new engine runs good.Bernie Link to comment Share on other sites More sharing options...
RivNut Posted May 12, 2012 Author Share Posted May 12, 2012 Bernie,I mentioned that to the guy who called me. He told me that the engine had just been overhauled and tearing it down was the last thing he would do. The rebuilder had used some aluminum balancer on it, so it was replaced with a nailhead iron one, still a vibration. I told him that the ring could have slipped on that. He's going to check that. He then called me back and said that he'd found a totally disintegrated transmisson mount and was looking for one of those. I told him to use one for a TH400 and modify the crossmember. I haven't heard from him since. Thanks for the input. I'll be sure to forward the pictures to him if he calls back.Ed Link to comment Share on other sites More sharing options...
60FlatTop Posted May 12, 2012 Share Posted May 12, 2012 "He told me that the engine had just been overhauled and tearing it down was the last thing he would do."A man with conviction! It reminds me of the time I asked my sister if the priest did her brake jobs.A friend of mine once quoted: "The level of perfection you can achieve is directly proportional to the number of times you are willing to do the job over again." Willing is the key word.Bernie Link to comment Share on other sites More sharing options...
RivNut Posted May 13, 2012 Author Share Posted May 13, 2012 The car was purchased on ebay. DUH. The buyer brought it to this mechanic to find the vibration after taking delivery of it. I think that this mechanic is trying to check out every other possibility in order to save the buyer some bucks before tearing down an engine that was overhauled by someone else. He's ready to tear it down if nothing else can fix it. Ed Link to comment Share on other sites More sharing options...
RivNut Posted May 15, 2012 Author Share Posted May 15, 2012 Update:I just got a call from the guy up in Leavenworth telling me that his customer's car is riding "smooth as silk." Come to find out it was two things that added up to some really bad vibrations at highway speeds. 1) the original transmission mount was compressed to the point where it was totally useless. I told him how to use a TH400 mount and modify the crossmember for that, and 2) someone had put a new carrier bearing on the driveshaft but didn't reinstall the shims under the bracket. Once the $6.00 trans mount was installed and the shims (which were tucked away someplace in the frame - $0.00 for those parts) were reinstalled, he has a very happy customer.Ed Link to comment Share on other sites More sharing options...
Jim Cannon Posted May 16, 2012 Share Posted May 16, 2012 That is weird, Ed, because when he called me, he told me that he had the vibration with the engine in Park at about 2500 rpm. That would not be caused by drivetrain angle. Link to comment Share on other sites More sharing options...
RivNut Posted May 16, 2012 Author Share Posted May 16, 2012 I asked him again about the vibration with the car in Park/Neutral and he said there wasn't one this time. I'm sure that he told me there was the first time I talked to him as well becasue we talked about balancers, broken piston skirts, etc. The guy is older than both of us put together - he was working in a Buick garage in 1965. But as he said, the only thing he was doing to "new" Buicks then was changing plugs, points, and condensers, or doing LOF's.Ed. Link to comment Share on other sites More sharing options...
60FlatTop Posted May 16, 2012 Share Posted May 16, 2012 Let's hope the engine rebuilder and the engine installer are two different people.Bernie"I wasn't born cynical and opinionated; I was taught." Link to comment Share on other sites More sharing options...
Guest pgadler Posted May 16, 2012 Share Posted May 16, 2012 That is weird, Ed, because when he called me, he told me that he had the vibration with the engine in Park at about 2500 rpm. That would not be caused by drivetrain angle.Couldn't a stand-still vibration be caused by a disintegrated trans mount? Or is the engine dampened and fixed completely by the engine mounts?I mean that it would not be a prop axle initiated vibration...I found this must interesting since I have same problem. Though I don't think it should be any engine internal, it moves like a bat out of hell Link to comment Share on other sites More sharing options...
JZRIV Posted May 16, 2012 Share Posted May 16, 2012 The guy is older than both of us put together Ed.Holy Cow Ed - Thats old - Doing the math he probably could have fought in the civil war too! Link to comment Share on other sites More sharing options...
RivNut Posted May 16, 2012 Author Share Posted May 16, 2012 Drummer boy for the 54th Iowa militia. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now