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ricosan

Drive line vibration

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I thought the first "Floating Power" Plymouths used coil spring mounts not rubber?

Nope....rubber.

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Hi ricosan, I would look to see if there is an inspection plate on the top of the bellhousing. If so, remove it and look the clutch pressure plate 'cover' and arms etc to see if there is anything not symetrical, like different size bolts or washers on the clutch, bent arms, missing springs etc. Anything that would change the rotating balance of the clutch assembly.

I'd also be concerned about and want to check to see if the flywheel is loose. This could be a big problem is the bolts have wollowed out the holes in the crank and or flywheel. If you can, put a pry bar on the outer edge of the flywheel, and gently pry/push it fore and aft. there will be a few thousandths of crankshaft endplay, but not a significant amount. usually about .003"-.008" for a big inline engine.

Your pilot bearing in the end of the crankshaft, that centers and supports the end of the trans' input shaft could be really bad, and allow the input to be off-center when the clutch is trapped between the pressure plate and flywheel. Usually if the pilot bearing is bad, the clutch will chatter badly when the clutch is engaging.

In your original description of the vibration and noises, it was reported that when you pushed in the clutch at speed, the vibration continued unchanged. I believe you have more than one source for vibration: the new driveshaft seems to have eliminated some of the problems, but not all.

Looking forward to the next bit of info.

GLong

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The factory brochure says the engine has a balancer on it. They call it a High frequency- oscillating vibration dampener in the

sales manual.

The "balancer" could also cause a vibration in the drive train.

kaycee

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Hey Guys,

Sorry about taking so long to get back. I came down with a nasty cold last week. I'm still not completely over it .

Here's a short update.

I took my car over to my mechanic a couple of weeks ago with the intention of pulling the transmission and balancing the flywheel/clutch. We discussed the vibration. He assures me that the car will make the round trip to Birmingham for the Marmon Muster in May. Since we are planning to pull the engine for a total rebuild this summer, it makes more sense to wait until then to address the flywheel/pressure plate then. We decided instead to pull the manifolds off the engine and adjust the valves and repair the wimpy leaky fuel pump.

The fuel pump wasn't much good after 50mph. I would have to switch to the electric fuel pump. Although I had a rebuild kit installed on the fuel pump shortly after I got the car (18 monrhs ago), the engine continued to be starved for fuel upon hard driving. It also leaked oil from the engine where the pump is bolted to the crank case. We discovered that the flange was warped. This may have been the wrong pump for this engine. We cobbled together a "fresh" pump from old pumps my mechanic had in his garage. When I tried to install the pump, it wouldn't go all the way in. We made an aluminum flange about .250 thick and bolted it into place between the crankcase and the fuel pump.

We then removed the valve covers and adjusted the valves. Put new gaskets on the covers and buttoned them back up. I reinstalled the manifolds to the engine with new gaskets. I torqued the manifolds to 15 lbs.

I removed all of the spark plugs and checked the compression again. Compression rose an average of 15lbs higher per cylinder than previous readings with several cylinders at 88lbs and one oddly at 62lbs.

After I reinstalled the plugs and reconnected the fuel lines, I pulled the choke out and touched the starter button for not more than 2 or 3 seconds. The engine burst to life and idled beautifully with the choke all the way back in. Even though I didn't get to drive it until the next day, I felt as if there was something different in the way it responded to just a little gas pedal at this stage. I couldn't wait to drive it on the road.

After the engine warmed I re-torqued the manifolds to 25lbs.

Yesterday I picked the car up and drove back home, about a twenty mile drive. Right away I could tell the engine had more power. Once I got out on the highway I cruised at 55 mph most of the way back with occasional jumps to 60mph. I drove at 65 for about a mile and the fuel pump performed beautifully! If I didn't have the vibration I think I could cruise a 60mph very nicely.

This was a BIG improvement!

ricosan

  • :)

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I'm real glad to hear that the car is on the road, even with a slight vibration. With this many recent miles, can you say with assurance that the vibration is in the rotating mass of the engine?? My test for this would be to be running say at 60mph, at the top of a hill, push in the clutch, let the engine go to a low idle as you coast down the hill. If the vibration is gone or 90+% gone, I believe the clutch cover and flywheel need balancing. IF the vibration is still there to some extent. Then at the top of the hill, push in the clutch, slide the trans into neutral, let the engine go to a low idle, and see if it is any different.

In the first test, with the trans still in gear, the clutch disc is spinning to match the road speed. In the second test, the clutch disc is turning at engine speed if the clutch is released, a low idle speed..

You should plan on replacing that aluminum fuel pump spacer you made with one made from some form of plastic, Delrin, or low heat-conductive material. The fuel pump spacers were created to heat-isolate the fuel pumps from the engine block. Reducing any tendency to vapor-lock.

Sound like you just about have it all figured out !!

Keep an 'eye' on that low 62# cylinder this summer, if it continues to drop, it could be a very bad valve, and if it leaks and burns badly enough, the head of the valve can break off or a piece can break off, and get into the cylinder bore and destroy a piston, score or ruin the engine block, or even break a piston and bend a connecting rod.. So just monitor the compression every few hundred miles to make sure it is stable or not going really bad, really fast.

The big increase in compression from before is because you have run the engine, any bits of carbon under any valves have been blown out from the engine running, and the cylinders are smoothed by the rings, the piston rings are lubricated by engine oil, and the rings have freed up in their ring grooves in the pistons.. ALL good stuff.

What was the compression before on that 62# cylinder ?? Any improvement in it like the others ??

Hey, enjoy your car ! It has been a several year saga to get it to this point !

GLong

Edited by GLong (see edit history)

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Kaycee - I checked the front of the engine with a flashlight and it does appear to have some sort of balancer attached to the crank. It has some material protruding from it ( rubber? ) That's definately going on the list for restoration this summer.

Greg - I'm really pleased with the progress I've made with the car this past year. Finding a knowledgeable mechanic has helped emensely. The driving experience continues to improve with every tiny advance. This summer after I get back from the Muster, We'll remove the engine and pull it apart. We'll balance everything as we rebuild. I want to have it painted but I may wait until next summer for that job.

Thanks again to all of you for the help and advise.

ricosan

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Have your mechanic check that dampener on the front of the crankshaft, With some rubber sticking out it, it very well may be ready to fly apart!! That type of dampener has a rubber ring bonded to the inner hub and outer ring of the damper. If the old rubber bonding has failed or is failing, then the outer ring can come off, and do a LOT of damage in the engine compartment!! Like ruin the radiator, and beat up the hood from the inside!

Better to know that it is OK than have it come apart on the way to or from the meet this summer !!

GLong

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When you have the engine out of the car, you will want to paint the firewall the color you plan to paint the car.

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Good Morning,

Greg - Thanks for the heads up on the balancer. I was hoping not to have to take it back in before the trip to Birmingham but this could be serious. I'm almost afraid to think it but this just may have a positive effect on the vibration! Are there any good balancer restorers that you can suggest?

Curti - That's a good suggestion but I plan a frame off when I paint. The paint is in really poor condition but the good news is that is has no rust or bondo for that I can see. My goal right now is to get the mechanical operation of the car as close to the way it was when the car was new. After that I'll concentrate on the electrical and paint.

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For vibration damper work you might contact these folks, they've done quite a few for me over the years, though none as early as yours.

http://www.damperdudes.net/

FWIW, re your vibration, I had a elusive vibration in an early Packard; I was thinking all kinds of dire thoughts and it turned out to be simply a failing ignition coil.

Edited by Owen_Dyneto (see edit history)

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Owen - Thanks for the address.

Here are some pictures of what I believe to be the harmonic balancer at the front of the engine. I can't make out what the "stuff" is coming out from the area where it is bolted. It almost looks like some type of gasket sealer? Does this balancer look like it has gone bad?

ricosan

post-97329-143143027635_thumb.jpg

post-97329-143143027642_thumb.jpg

post-97329-143143027665_thumb.jpg

Edited by ricosan (see edit history)

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Hmm, this is not the type of dampener I was visualizing. This does not look like it can come apart and do any damage without the bolt backing out and the big thick washer coming off ?? I can't see quite well enough to be sure.

GLong

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Hmm, this is not the type of dampener I was visualizing. This does not look like it can come apart and do any damage without the bolt backing out and the big thick washer coming off ?? I can't see quite well enough to be sure.

GLong

This doesn't look like the dampers I'm used to although I've had little experience with dampeners or harmonic balaners especially on antique cars. I just want it to hold together for another thousand miles or so then we'll deal with it when we get a better look on tear down this summer.

A side note -

The car is running better than ever. The valve adjustment was a big improvement. Yesterday I was driving at 50 mph and "punched" it. It went right up to 65 mph. I don't know if it was my wishful imagination or not but I swear I felt little of that feeling of being pushed back into the seat!

ricosan

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With the caveat stating that since I have not seen, touched or worked on your car, from what I see, I don't think that dampener can come off just because some rubber-bonding failed. It looks like it is a metal-to-metal type of dampener, not a bonded rubber dampener.

So I think you are safe to drive it to your upcoming meet.

You might take a look at the damper while the engine is idling slowly. Look for any obvious wobble or out of round or off center of the large disc.

Several of my Pierce Arrow engines have a damper inside the timing chain cover. It is lubricated by engine oil. The damper is a steel ring that is clamped to a flange installed on the end of the crankshaft. The ring is clamped to the flange with several stiff coil springs providing a steady amount of pressure, creating friction between the the disc and the flange.

The dampening action is the ring slipping on the flange if there is strong enough of a vibration in the crankshaft and rotating masses.

Your damper may be designed to slip where someone put the Blue Silicone sealant.. no way to know for sure without taking it off the car.

Take care, have a great time at your meet and tours !!

GLong

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