Can I use a 1950 Desoto Damper on a 1951 Dodge?

[48ragtop]

I've been sorting out a 1951 Dodge Roadster I bought a couple of years ago. It has a standard 3 speed in it.  One of the last things to sort is a vibration in the engine that comes in at certain Rpms and then goes away as they increase, until the frequency comes back around at a higher RPM.  The car had extensive Restoration work and was completely apart at which point it was sold and finished by someone else.  I believe the vibration is the engine is unbalanced.  It currently has no damper on it. 

I know they were randomly put on Dodges in this era so it may have never had one.  I would like to add one.  I currently have a lower pulley with no holes for one.  I do have access to a complete damper with hub and pulley from a 1950 Desoto with Fluid Drive.  Can this be used?  According to the 1953 parts book,  the hubs all have the same number so it looks like it will physically bolt on,  but will the pulleys line up and will the weight be properly aligned to give me the counterbalance that an original damper for the car (shows as a different number) will?

 

I did check the motor mounts before getting this far and they are all good.  I even disconnected the rears and put a little up pressure with the jack to make sure they weren't touching and still had the vibration.  So pretty sure it's the engine being unbalanced. 

 

[Dodgeb4ya]

Could be the FD coupling too.

I have replaced two of them because of vibration.

I have also seen rebuilt FH engines that had been rebuilt with mid throttle annoying vibrations.

Both with replaced connecting rods.

[Adam H P15 D30]

This ^^^^^  My 49 has no damper and is smooth as silk.  Probably the pressure plate or fluid drive unit.  If the engine is that far off balance, you have more problems than a damper could fix.

[48ragtop]

Well seems like a damper will help. Can't hurt.  Infact it seems the way Dodge applied them,  they stuck them on cars that came off the line with a problem,  almost as an afterthought fix, otherwise they would have all had them and would have been a unit that doesn't slip over the big nut and would have been all one piece.  It's hard to describe how bad it is.  It's not going to shake your fillings out,  but it is noticeable,  especially to someone who is in tune to picking stuff like that up.  Now the Ujoint I replaced was ridiculous. 

 

So does anyone know if it will work? 

 

[48ragtop]

It's a 3 speed manual transmission.

[Sniper]

18 minutes ago, 48ragtop said:

So does anyone know if it will work? 

 

If you are asking does it work as in will it fit the crank, yes.

 

If you are asking will it fix the problem, most likely no.

 

 

[48ragtop]

Well they put them on for a reason so not all must have been vibration free without one.  The factory rarely adds parts that aren't needed.  I have no idea if it ever had one or if this was even the original engine to the car.  Being it was all apart anything is possible and even probable after all I have fixed so far. 

 

Is it indexed any chance differently between a desoto and a dodge,  thus the reason the different numbers?  If it counterbalances it the wrong way it will aggravate the problem not alleviate it. 

[Dodgeb4ya]

I had a D41 3 passenger coupe.

Never had a damper.

The original engine was very smooth running.

[kencombs]

The crankshaft dampener is not intended to cure out of balance vibration as they are all neutral balanced.  No counter weighting or out of balance to counteract internal balance errors.  The are intended to dampen torsional twisting induced by the long crankshaft twisting slightly with piston power strokes.

 

Their inertia overcomes that twisting tendency.

 

They seemed to be used mostly on trucks subject to high loads or cars that were expected to be ultra smooth.

[DJ194950]

Have you removed the inspection cover under the bell housing and checked to see if the flywheel nuts/bolts  to crank  are tight!

 

Mine somehow got loose on a standard  clutch/3 speed trans that started to vibrate some after a short time after rebuilt engine and trans,  retightened good and problem never returned-Maybe I did that part when I was feeling somewhat weak? Me thinks a fluid drive setup maybe even more touchy to slightly loose bolts to crank?

 

DJ

Edited May 21, 2021 by DJ194950
add which bolts-tighten