Ideas for vibration problem in 59A

Old Henry

Old Henry

Well-known member
Just picked up Old Henry from the garage that's spent the last month trying to fix my engine. It started very quickly and ran smoothly up to about 45-50 MPH, probably about 2,000 RPM's, when a bad vibration came and only got worse the faster I went. (Sometimes there is a certain RPM with a vibration that goes away once you get past it but this didn't.) I went back to the garage about it and here's what they'd done: As reported in my previous thread about this problem, (here: http://www.fordbarn.com/forum/showthread.php?t=147626) the bearings were worn out and needed to be replaced but the crankshaft that was in the engine (that had been put in by my previous builder to replace the original that had a loose pulley on the front) had already been machined to the point that no bearings were available if it was machined any more. But, my original crankshaft, that I still had, had not been machined at all so had plenty of surface to machine to fit new bearings. So, that's what was done.

I hesitated to suggest anything to the mechanic because he seemed experienced so I didn't. I didn't find out until after the job was done that mine was his first flathead and he was having to look up everything to do and consult with Mac VanPelt all along the way.

So, when I went back to talk to them about the vibration, he admitted that he had experienced that when he test drove it but didn't say anything about it because he thought maybe it was normal.

So, now we talk about what the problem is and what to do about it. The only idea anyone comes up with is to balance the crankshaft which, of course, requires removing and disassembling the engine. On my dime, of course. Why they didn't have it balanced when it was at the machine shop they couldn't really say other than "We didn't think it needed it." or "You didn't ask us to balance it". Duh. I thought I ended up paying a whole lot of money for their knowledge about these things. Now I find out that I didn't really get what I paid for.

Any other ideas of what would cause the vibration and what to do about it?

Thanks to all for your help.

P.S. I don't need any snide or derogatory remarks about me or the mechanic. I need helpful suggestions to pass on to him now that I know I've got to educate him more than I had supposed.
 
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That's not good. Do you recall if during one of the prior rebuilds the crank and flywheel were balanced as a unit? Your replacement crank might have thrown that off. Are the weights of the piston and rod assemblies matched. That could be a factor. Were any of the clutch components changed as part of this rebuild?
 
If the vibration occurs at three different road speeds in 1st, 2nd and 3rd gear, in other words at a certain engine speed range it is the engine. if only at a certain road speed, but is not affected if you are in (lets say) 2nd or 3rd, then it is not the engine. The only thing I can think of that it may possibly be, if not engine/clutch/flywheel related, would be due to the tires flat-spotting. This would correct itself as it gets used more. But, the reality is, it is probably engine related and can only be fixed by a balancing job.

Hope this helps.

Mart.
 
If the vibration occurs at the same RPM in neutral, first, second, and high gears and after loosening or removing the fan belt I think you have a balance issue with the clutch or the engine rotating parts.

EDIT: Mart types faster than I.
 
The vibration begins at a certain RPM regardless of gear or even stopped in neutral so it's definitely the engine.
 
Hi Henry, try to post all the parts (and numbers if you have them) that you know were replaced inside the engine.

The mere fact of replacing your original crank with the one removed, even though it's been cut, should not have a major effect on the balance condition! This is assuming most parts are close to original? Even changing all 8 pistons with nominally different weights usually won't cause any vibration!

If it is in the engine area the chances of the flywheel and clutch ***'y being the culprit sound pretty good. The flywheel/pressure plate on these "Flatties" should NOT be mounted on the crank when balancing the rotator, it isn't necessary! It should all be independently run up. I have no problem balancing the flywheel/pressure plate ***'y as a unit, BUT, it must be indexed as it was when mounted on the balancer.

Thanks, Gary in N.Y.

P.S. These builds SHOULD be balanced when changing components to ensure there are no issues like you are having here! We even recommend balancing these ***'y's on a basic rebuild! Some customers feel it isn't really necessary! Only the "balancer" really knows for sure though!
 
You had said the original crank had a loose pulley and that the crank had to be replaced.
If they used this crank this time, what was done to resolve this problem? Could this be your vibration?
 
GOSFAST said:
Hi Henry, try to post all the parts (and numbers if you have them) that you know were replaced inside the engine.
Click to expand...

Other than the standard gaskets, the only working parts replaced were new bearings and the original crankshaft machined 10 under and installed. No change of pistons nor rods.
 
46Merc said:
You had said the original crank had a loose pulley and that the crank had to be replaced.
If they used this crank this time, what was done to resolve this problem? Could this be your vibration?
Click to expand...

The loose pulley was just the slot in the pulley where the key goes worn. Moved the key and pulley from the latest crankshaft to the old original and it was just fine.
 
Old Henry said:
The loose pulley was just the slot in the pulley where the key goes worn. Moved the key and pulley from the latest crankshaft to the old original and it was just fine.
Click to expand...

Then why did your first rebuild mechanic want you to change crankshafts? Did he give you a reason?

Lonnie
 
My suggestion would be to NOT just balance the crank. If it is coming apart you need to have the whole assembly balanced. That includes weighing the pistons along with the rings and pins. The rods need to be weighted both ends and the bearings. All of these components are then brought to a similar weight. Weights are then placed on the crank to simulate these components. The crank is then balanced, then the flywheel and the index to the crank marked. Then the pressure plate and clutch which are also indexed.
 
Binx said:
Then why did your first rebuild mechanic want you to change crankshafts? Did he give you a reason?

Lonnie
Click to expand...

That was the only reason he gave - because the pulley was loose. If there was any other reason he didn't tell me. I was having no trouble with that crank before that rebuild.

How can one know whether a crank has a problem and what it is and whether it can be fixed and used?
 
I have a 59a and has a rap thru 1-2-3rd.
I'm new to the floating bearing and was talking to a machine shop about the rods.
He said he would file the cap and hone to size. That's maybe and old trick but I would have good rods to begin with and no filing.
You could have a mix of rods, different lengths,you could try another pulley.
I found a crank and rods from and engine with cracked block and parts were removed.
Hope to swap and fix my engine. I did replace it with 53 8rt and who knows may just sit in garage. You will find out when you check parts.
 
Does the vibration decrease with the clutch in and the trans in gear? I am thinking it may be the disk. A bad pilot bearing will let the disk get off center. I had one disk that the springs had worn and it caused a bad vibration. I also had a bad vibration and it was the fan. Try removing the belt. Hope you get it fixed easily. Andy
 
Andy said:
Does the vibration decrease with the clutch in and the trans in gear? I am thinking it may be the disk. A bad pilot bearing will let the disk get off center. I had one disk that the springs had worn and it caused a bad vibration. I also had a bad vibration and it was the fan. Try removing the belt. Hope you get it fixed easily. Andy
Click to expand...

When I push in the clutch while driving and let the engine slow down the vibration is gone.
 
I'm trying to get my head around what Andy said, but I think I understand it, he is saying to have the car standing still, in gear, and rev the engine with the clutch released (pedal down). the flywheel and pressure plate will be spinning, but the driven plate will not.

If the vibes go away, the problem is with the driven plate or possibly the pilot bearing.

If the vibes persist, it does nothing more than rule out those parts as the cause of the problem.

Worth a shot, as the effort to do it is minimal. (although to be honest, while I would love for the problem to be relatively simple like this, I fear the motor will need yet another tear down to get the balance into spec.)

Maybe a good serviceable flywheel that has never been skimmed would improve the situation?

Mart.
 
The vibration begins at a specific engine RPM regardless of whether the car is in gear, out of gear (in neutral), clutch in, clutch out, 1st gear, 2nd gear, or 3rd gear. When the engine is not spinning at or above that RPM there is no vibration regardless of whether the car is in gear, out of gear (in neutral), clutch in, clutch out, 1st gear, 2nd gear, or 3rd gear.
 
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