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Old 04-08-2020, 08:50 PM   #1
flan30
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Default crank pulley issue

My father inlaw recently purchased a 1929 tudor in non running condition. I rebuilt the carb and when I was setting the clearance between the rotor and distributor cap I was using the fan blade to spin the engine around and as usual there was some resistance in doing so do to compression in the cylinders and all of a sudden the fan blade started free wheeling. looking down at the crank pulley I could see it spinning but not the crank shaft. I removed the crank shaft pulley bolt and it appears to have a sleeve over the crank shaft and the pulley rides on the sleeve and does not appear to have a key way. It looks like the sleeve sits just slightly past the pulley which would prevent the crank bolt from tightening up against the pulley. Is this some sort of accessory that might be missing a washer. I don't see any of the vendors offering anything like this in the catalogs maybe some one has run into this before or should I just put a stock pulley on the car. thnks Jim
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Old 04-08-2020, 09:46 PM   #2
Joe K
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Default Re: crank pulley issue

The crank pulley is "located" to a spot on the crankshaft by a "slot" which matches the single key which holds the crank small timing gear. This slot and key keep the pulley from turning by itself.

If the whole crank pulley including it's sleeve is turning then there is chance that the crank pulley "ratchet nut" (the one which the starter crank ratchets into) may have backed off and the whole crank pulley has moved forward. The slot thusly loses engagement with the key and allows the crank pulley to turn relative to the crank.

The solution (and a check) involves removing the ratchet nut, removing the crank pulley, examining for the key and slot to be sure they are not damaged, and then reassemble keeping the pulley slot aligned to the gear key, and tightening the ratchet nut down.

You will find that the crank pulley sleeve has a short "taper" at its innermost end: this taper is by design and allows one to remove the crank pulley and a way for the sleeve to "re-compress" the rope packing on timing cover and oil pan as you push it back into place.

If you have a one piece crank pulley you will have to pull the radiator to do this. You MAY have to un-do the front motor mount either below the frame, or at the two horns. If you have to do this be sure to loosen the four bolts holding the motor into the rear mounts. Then you can use a board and a jack and lift the front of the engine only to get clearance to remove the crank pulley.

A two piece crank pulley you probably remove the radiator for convenience (and prevent bashing in the fins on the back side) but the two piece pulley/sleeve (two parts) can be removed without elevating the motor.

Hope this helps.

Joe K
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Last edited by Joe K; 04-08-2020 at 09:59 PM.
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Old 04-08-2020, 09:53 PM   #3
Joe K
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Default Re: crank pulley issue

There are three varieties of crank shaft pulley.

Original Type: The pulley rim is spoked, and the hub is made solid with the spokes/rim. Held in engagement with the crank gear key by the ratchet nut.

Replacement No. 1: The pulley rim is spoked, but the hub is separate from the spokes/rim and driven by a square "dog tooth." And held in engagement both crank gear key and dog tooth by the ratchet nut.

Replacement No. 2: The pulley rim is spokes, or possibly solid, but the hub is separate from the pulley sheeve, but "screwed" into place. The threads on these tend to rust in place making disassembly difficult. The ratchet nut is not needed for thread engagement but like Original is necessary to keep parts engaged with the crank gear key.

Again, hope this helps.

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Old 04-08-2020, 10:54 PM   #4
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Default Re: crank pulley issue

In addition to what Joe K says above, if you need to raise the front of the motor, it is best to remove the blots from the rear engine mounts. Failure to do so is likely to result in a cracked flywheel housing.
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Old 04-09-2020, 06:56 PM   #5
flan30
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Default Re: crank pulley issue

Thank you Joe K. and synchro909 for your input its probably going to be a few days before I can get back to you, the weathers kind of nasty so I'll wait until it warms up a bit to before I start working on it again. But it appears to be a two piece design, pulley separate from the hub.
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Old 04-09-2020, 08:01 PM   #6
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Default Re: crank pulley issue

Quote:
But it appears to be a two piece design, pulley separate from the hub.
If that the case removal of the pulley portion comes with removing the ratchet nut. Getting the sleeve backed out of the front of the motor will be the next challenge.

May be a job for Vise-Grips. Or possibly water pump pliers. Worst case remove the bolts and raise up the timing gear cover (this can be done with the generator attached) enough to loosen the rope seal - or get a screwdriver behind the sleeve to pry forward. Rust is not your friend. PB Blaster is.

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Old 04-12-2020, 08:46 PM   #7
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Default Re: crank pulley issue

ok I was able to spend some time on the 29 today and raised the front of the engine as instructed and was surprised as to what I found the pulley actually threads onto the hub. When I first looked at it you could see that the pulley moved left to right free of the hub but when I tried to slide it off of the hub the hub moved with it. I spun the pulley counter clockwise and the pulley stopped yanked it back clockwise and kept spinning it and said son of a gun its threaded. Now I'm new to working on model A's but my father in law has owned his owned his 28 for fifty years and he's never seen one set up like this one. Any way looking at the way its designed with a left hand thread its not going to come off. I put a little blue Loctite on the threads when I put it back together and the ratchet nut just holds the hub onto or up against the crank timing gear and I double checked the ratchet nut is slightly larger than the pulley so even if it did loosen up again it can't get past the ratchet nut. Joe K you did mention that they made three types of crank pulleys is this one of them or is this some aftermarket set up.


Thank you again for your help.
Jim
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Old 04-12-2020, 09:07 PM   #8
Bob C
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Default Re: crank pulley issue

This is probably what you have. https://www.mikes-afordable.com/product/A6312A.html
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Old 04-12-2020, 10:03 PM   #9
flan30
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Default Re: crank pulley issue

Yes that pulley looks a little different but the overall design is the same. Thanks Bob C
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Old 04-12-2020, 10:26 PM   #10
Chuck Sea/Tac
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Default Re: crank pulley issue

You really should not use the fan blade to turn the engine over. Use a crank, a special wrench venders sell , or a socket with the extension through the crank hole.
You can also use the starter to bump it.
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Old 04-13-2020, 10:34 AM   #11
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Default Re: crank pulley issue

Gang, when the 2-piece pulley came out (or at least when I became aware of it), it was ballyhooed as being a huge improvement for replacement. It seems to me you guys are saying the two-piece design actually presents its own issues for removal. Am I reading this wrong?
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Old 04-13-2020, 06:11 PM   #12
Joe K
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Default Re: crank pulley issue

Quote:
Originally Posted by ericr View Post
Gang, when the 2-piece pulley came out (or at least when I became aware of it), it was ballyhooed as being a huge improvement for replacement. It seems to me you guys are saying the two-piece design actually presents its own issues for removal. Am I reading this wrong?
The two piece pulley with the "dog clutch" style joint MOSTLY can be removed without raising the engine. Some engines can be "down front" due to wear, compressing of the springs, conversion to rubber donut, "float-a-motor", or front end damage.

The two piece pulley with the threads SHOULD be able to be removed without raising the engine - except the two parts tend to rust together and resist separation. So, a nice idea which was kind of self defeating in actuality.

I have had a two piece dog clutch style "turn" and separate. This what happens apparently when you get your arm tied up in the starting crank and thereby inadvertently "undo" the ratchet nut - besides hurting yourself. With the ratchet nut undone a bit, the dog clutch style can "slip," and you may not even know it.

So even the convenience of this two piece pulley has a downside.

Loctite helps...use blue for this.

The slipped ratchet nut MAY be the reason I didn't break my arm. Just a nasty bruise.

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Old 04-13-2020, 06:17 PM   #13
Jack Shaft
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Default Re: crank pulley issue

Crankshaft harmonic imbalance fractures crank pulleys.Harmonic balancer fixes the root cause of the failure.
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Old 04-14-2020, 10:14 PM   #14
flan30
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Default Re: crank pulley issue

I won't say I see anything wrong with this type of pulley set up now that I've taken it apart and looked things over, but when I first looked at it I was under the impression that model A's had a one piece pulley and this one definitely had a two piece set up in it. Like I said I'm new to working on model A's so I reached out to those with more experience, now that I know what's in the car i'll know what not to do the next time. I greatly appreciate the knowledge and wisdom I'm receiving from all of you.


thanks Jim
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Old 04-15-2020, 12:54 PM   #15
30 Closed Cab PU
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Default Re: crank pulley issue

Quote:
Originally Posted by flan30 View Post
I won't say I see anything wrong with this type of pulley set up now that I've taken it apart and looked things over, but when I first looked at it I was under the impression that model A's had a one piece pulley and this one definitely had a two piece set up in it. Like I said I'm new to working on model A's so I reached out to those with more experience, now that I know what's in the car i'll know what not to do the next time. I greatly appreciate the knowledge and wisdom I'm receiving from all of you.


thanks Jim


I have the 2 piece, have not had issues. But as a part of maintenance inspect it frequently to make sure it is OK - so far (3 years) no issues.


If they loosen, then things go south. Or if the assembly does not properly seat together, and against the crank properly.
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