Crank pulley wobble

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hglouis

hglouis

10 Year 15 Year
Joined
Mar 12, 2009
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Location
Charleston, SC
Hi list,

So the crank pulley (if im not calling it the correct name, it's the one that drives the belt that drives the water pump and alternator) has had a good wobble in it since I got the truck 8 months ago. No knocking or sounds, just wobbles quite a bit and vibrates the belt. Drives great.

Is the best way to go about this to:

A) Remove the radiator to get to the nut and check first to see if its just loose
B) Tighten the nut without removing the radiator (how?)
C) Panic that my crank is shot
D) Your suggestion:


Thanks for the help and any diagnostic advice.


Hunter

PS The gas in the oil fiasco months ago worked out great if you followed that thread. A few oil changes and its holding pressure now.
 
Best would be to remove the pulley and figure out if the crank keyway or pulley seating surface, or if the pulley has been damaged...
 
If you don't remove the balancer and check the condition of the condition, you could be missing out on something....
 
Unusual datapoint: A customer called recently, wanted to know if it was normal for the balancer to have 1/4" of obvious runout.

Umm, heck no.

He said he didn't recall the wobble, but after he got the balancer back from powdercoat and reinstalled it had this very obvious wobble.

Wait, you stuck the rubber balancer in a 500* powdercoat oven?

Yes, it looks great!

You need a new balancer, mang

The moral of the story: don't put rubber parts in the oven.
 
There's just SOMETHING about the way you make a point Jim!

Part PBS, part HBO!;p

On a more serious note, I'm with the others on pulling the thing off to check the crank. And if it's your daily driver, it wouldn't hurt to have a timing cover seal and a second harmonic balancer on hand, as well as the locktab for the locknut.

Come to think of it, it wouldn't hurt to have the key for the crank on hand too! Went down this road with Dom Smith a couple of years ago.

Best

Mark A.
 
grant5127 said:
If you don't remove the balancer and check the condition of the condition, you could be missing out on something....
Click to expand...

Yogi Berra couldn't have said it better himself...:lol:
 
I was only pokking pun in my last post but.........

Think of it this way, that "Pulley" as you call it is really a "HARMONIC BALANCER"

Every time the cylinders fire, torque is imparted to the crankshaft. The crankshaft deflects under this torque, which sets up vibrations when the torque is released. At certain engine speeds the torques imparted by the cylinders are in synch with the vibrations in the crankshaft, which results in a phenomenon called resonance. This resonance causes stress beyond what the crankshaft can withstand, resulting in crankshaft failure.
To prevent this vibration, a harmonic balancer is attached to the front part of the crankshaft. The damper is composed of two elements: a mass and an energy dissipating element. The mass resists the acceleration of the vibration and the energy dissipating (rubber) element absorbs the vibrations.
Additionally the energy transferred from the piston to the crankshaft can induce as much as 2 degrees of twist in the crankshaft, which has many follow-on effects on all engine elements that require adequate timing such as valve opening, cam timing, ignition timing etc.:eek:............

So with that being said, do you really want that thing sitting out there on the end of your "WIGGLE STICK" wobbling around? :meh:


 
Another part in that area that should not be powder coated is the timing cover. The seal housing is actually soldered into the cover and if baked the solder melts and runs out. Ask me how I know....
 
grant5127 said:
I was only pokking pun in my last post but.........

Think of it this way, that "Pulley" as you call it is really a "HARMONIC BALANCER"

Every time the cylinders fire, torque is imparted to the crankshaft. The crankshaft deflects under this torque, which sets up vibrations when the torque is released. At certain engine speeds the torques imparted by the cylinders are in synch with the vibrations in the crankshaft, which results in a phenomenon called resonance. This resonance causes stress beyond what the crankshaft can withstand, resulting in crankshaft failure.
To prevent this vibration, a harmonic balancer is attached to the front part of the crankshaft. The damper is composed of two elements: a mass and an energy dissipating element. The mass resists the acceleration of the vibration and the energy dissipating (rubber) element absorbs the vibrations.
Additionally the energy transferred from the piston to the crankshaft can induce as much as 2 degrees of twist in the crankshaft, which has many follow-on effects on all engine elements that require adequate timing such as valve opening, cam timing, ignition timing etc.:eek:............

So with that being said, do you really want that thing sitting out there on the end of your "WIGGLE STICK" wobbling around? :meh:
Click to expand...

All those years of getting an education in Inguneerun and there is still no way I could have said that better. To ad another ask me how I know to this.......You know that timing gear that mounts to the the end of the camshaft. No Siree, never preheat that for fitment. Really, really, really bad idea! :rolleyes: And this was a camshaft shop! That rubber isolation ring makes quite the stink, or so I hear.
 
The harmonic balancer is often machined with the crank. There could be some other issues if you put on a different one. I have always considered the harmonic balancer a part of the crank so if I use a different crank, the harmonic balancer goes with it or a rebalance is in order.
 
Last edited:
FJforty said:
The harmonic balancer is often machined with the crank. There could be some other issues if you put on a different one. I have always considered the harmonic balancer a part of the crank so if I use a different crank, the harmonic balancer goes with it or a rebalance is in order.
Click to expand...



Not the case for these F/2F tractor engines....



:meh:
 
My balancer was bad and wobbled for years. New key didn't fix it, tried that twice. It probably did this for 25k miles that I know of, maybe longer. Last year when the machine shop was getting ready to do the balancing on my 2F he asked for the flywheel and balancer. He took one look at the balancer and handed it right back to me and told me to throw it away.
 
I've seen this issue happen on a friends cruiser. Was caused most likely from the PS belt being to tight and a really bad engine rebuild in the past.

Once the crank pulley was off he could see it had been eating the crank. He had two options. Weld the pulley on or take the motor out and source a new crank.

He pulled the motor. Once the engine was opened up it was a can of worms. Ended up replacing the whole motor.

If it is the crank I'd replace the timing cover gaskets and crank seal and then weld the crank pulley on knowing one day your going to have to source a new crank, pulley and most likely a new timing cover.
 
Trollhole said:
I've seen this issue happen on a friends cruiser. Was caused most likely from the PS belt being to tight and a really bad engine rebuild in the past.

Once the crank pulley was off he could see it had been eating the crank. He had two options. Weld the pulley on or take the motor out and source a new crank.

He pulled the motor. Once the engine was opened up it was a can of worms. Ended up replacing the whole motor.

If it is the crank I'd replace the timing cover gaskets and crank seal and then weld the crank pulley on knowing one day your going to have to source a new crank, pulley and most likely a new timing cover.
Click to expand...

Awwww, you called me a 'friend'! :crybaby: <---- tears of joy

Yes, that was me. Little knock when I was turning the wheel at a stand still and Trollhole and DanKunz pointed to the problem. Little problem became a big problem - but at least I didn't find out the hard way with a motor disintegrating in the middle of nowhere.
 
So to get started on this, do I have to pull the radiator and bibb to get at what I need to get at?

Do you have to use a puller?

Can I sneak a half inch ratchet with a big socket on it (i think i read its a 1"15/16 or something) down between the radiator and the nut?

Thanks!
Hunter
 
Does anyone know where to buy a good crankshaft pulley, claw nut, key, lock plate, etc. for a 2F (1978 40)?

New or otherwise - I've been looking at the same chewed-up one on eBay for a year. I think SOR had a new one (after-market-big $) for a while, but now ...?

Thanks :)
 
Just threw one of those away.

Try the classified, oughta be somebody parting a F/2F w/ 2-groove balancer.

The 3-groove balancer is definitely still available from the dealer.
 
FJ40Jim said:
Just threw one of those away.

Try the classified, oughta be somebody parting a F/2F w/ 2-groove balancer.

The 3-groove balancer is definitely still available from the dealer.
Click to expand...

Thanks Jim - dumb question - is the 3-groove just for newer - air, whatever - or can a newer 3-groove be used as a replacement for the 2 (belt spacing, balance, etc.)?
 
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