Sources of vibration?

Here's the dilema: My 64 Stude V-8 has developed the "shakes" when the car is idling in drive, but it is smooth in park or neutral, and vibration is not noticible when going over a few miles per hour. The carb has been rebuilt, it has new Stude V-8 engine mounts, the harmonic balancer looks okay, the torque converter has been rebuilt, and the mechanic working on it right now (specializes in older cars, but not Studes particularly) is stumped because he doesn't think its the engine...the compression readings are fairly even at 120 -140 and the engine itself seems okay, doesn't think it has a miss but possible. Possibly its in the trans, but the torque convert was rebuilt (old one sounded like a box of metal rocks when pulled)and there doesn't seem to be another source of vibration, although I've wondered if it could be in the mis-alignment of belts with the Vintage Air added by prior owner getting worse over time. Any tips for possible mis-alignment of trans, or torque converter, or maybe driveshaft or belts? Just looking for some possibilities that could be explored without major surgery. Otherwise, the car is solid, and drives and handles very well. Any suggestions appreciated!

Hank

[Dick Steinkamp]

quote:Originally posted by Rekabeduts

Here's the dilema: My 64 Stude V-8 has developed the "shakes" when the car is idling in drive, but it is smooth in park or neutral, and vibration is not noticible when going over a few miles per hour.

Could it be something as simple as your idle speed is set too low?

[Dwain G.]

Sorry, but it certainly does sound like an engine problem. An ignition scope should find the problem quickly. Lacking that, momentarily remove one spark plug wire at a time and listen/feel for a change in the idling. Eventually you will probably remove a wire that has no effect at all on the idle. That will indicate the problem cylinder, then you'll need to find out why it isn't firing correctly. Very well could be a vacuum leak. Spray some carb cleaner around all the manifold gasket surfaces and see if the engine smoothes out. Does this car have power brakes? What has been done to the engine lately? A valve adjustment?


Dwain G.

[bigaadams]

IF it shakes when in drive..that would suggest that there is a shift in the engine/transmission allowing it to contact the chassis at some point. Would take a close look at transmission mount..linkage etc...with new mounts on the engine check them for proper fit and such.

[64V-K7]

When you put it drive, a load is introduced. To accomodate the load, the timing changes, which could be affected by a vacuum leak, bad plug/wire or carb adjustment

[skyway]

...and of course there is always the flex plate to consider?

[studeclunker]

I have one that does the same thing. You've replaced the torque converter, have you cleaned the screen and changed the oil in the transmission? It would behoove you to look there. The TC and the tranny both share the same fluid. Therefore, if the TC went to pieces, it could have shared some of it's debris with the tranny. The problem could be solved with just a cleaning.


Lotsa Larks!
K.I.S.S. Keep It Simple Studebaker!
Ron Smith
Where the heck is Lewiston, CA?

[Rekabeduts]

Thanks Dick,

I have set the idle at a higher speed, which helps, but its still there when in drive but sitting still. It could be the engine as noted below, but the odd thing is the engine itself don't appear to be jumping around. I still suspect it has to do with the transmission.

Hank

quote:Originally posted by Dick Steinkamp

quote:Originally posted by Rekabeduts

Here's the dilema: My 64 Stude V-8 has developed the "shakes" when the car is idling in drive, but it is smooth in park or neutral, and vibration is not noticible when going over a few miles per hour.

Could it be something as simple as your idle speed is set too low?

[Rekabeduts]

Thanks, I wonder if the tranny is shifting enough to hit the crossmember when put into drive. Will be tricky to check out but will suggest that to the mechanic.

quote:Originally posted by bigaadams

IF it shakes when in drive..that would suggest that there is a shift in the engine/transmission allowing it to contact the chassis at some point. Would take a close look at transmission mount..linkage etc...with new mounts on the engine check them for proper fit and such.

[Rekabeduts]

Could be. He did most of what has been suggested but didn't ask about that one.

Hank

quote:Originally posted by skyway

...and of course there is always the flex plate to consider?

[Rekabeduts]

Thanks for the suggestion. I assume he had to put new trans fluid back in after the tranny was dropped to remove the Torque converter, but maybe not. Seems reasonable that some parts could be stuck in the screen too.

quote:Originally posted by studeclunker

I have one that does the same thing. You've replaced the torque converter, have you cleaned the screen and changed the oil in the transmission? It would behoove you to look there. The TC and the tranny both share the same fluid. Therefore, if the TC went to pieces, it could have shared some of it's debris with the tranny. The problem could be solved with just a cleaning.


Lotsa Larks!
K.I.S.S. Keep It Simple Studebaker!
Ron Smith
Where the heck is Lewiston, CA?

[DEEPNHOCK]

Did you try to check your plug wire routing?
Stude's are infamous for an inductive misfire with the 5-7 wires (IIRC).. (You can check that for free, too)
Remember...It's a simple machine with simple solutions...Don't overcomplicate it all.
Jeff[8D]



DEEPNHOCK at Gmail.com
Brooklet, Georgia
'37 Coupe Express (never ending project)
'37 Coupe Express Trailer (project)
'61 Hawk (project)
http://community.webshots.com/user/deepnhock

[Rekabeduts]

Hi Jeff,

Thanks for the good advice....it seems like it should be simple. Have a great weekend at The Villages car show this weekend. Looks like you'll have cool but nice weather.

Hank

quote:Originally posted by DEEPNHOCK

Did you try to check your plug wire routing?
Stude's are infamous for an inductive misfire with the 5-7 wires (IIRC).. (You can check that for free, too)
Remember...It's a simple machine with simple solutions...Don't overcomplicate it all.
Jeff[8D]



DEEPNHOCK at Gmail.com
Brooklet, Georgia
'37 Coupe Express (never ending project)
'37 Coupe Express Trailer (project)
'61 Hawk (project)
http://community.webshots.com/user/deepnhock

[nels]

Check to make sure the spacer is between the crossmember and the driver's side transmission mount.

[dave smith]

I don't remember if studes have offset mounting of flexplate to converter or not. if not sometimes reindexing converter to flexplate
will solve this problem