Author Topic: Crankshaft shimming  (Read 3161 times)

Online RichardL

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Re: Crankshaft shimming
« Reply #75 on: 18.01. 2021 20:24 »
Musky,

I recall your showing that before. You might have mentioned that it could work on the upper lip with the rollers removed. I could basically see that, but the radius of the grabber seems wrong. Definitely would not work grabbing beneath the lower lip, because the shims are in the way. If I ordered it now from Oz I suppose I would have it in about a month for some tremendous shipping cost. Haven't looked for it on eBay yet.

Richard L.
Plan on signing up for the world-wide 2020 DISTINGUISHED GENTLEMAN'S RIDEon September 27, 2020. This year it's a solo or pillion ride in dapper attire. Watch website at https://www.gentlemansride.com for details.


Offline muskrat

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Re: Crankshaft shimming
« Reply #76 on: 18.01. 2021 22:13 »
G'day Richard.
It will work as you described and also with the rollers in but clamped with a hose clamp. It won't go between the bearing and crank web.
Surely there would be a place over there that has them. Harbor Freight comes to mind. https://tinyurl.com/yyh87j79
Cheers
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Online RichardL

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Re: Crankshaft shimming
« Reply #77 on: 19.01. 2021 00:00 »
Musky,

That's pretty funny. Harbor freight is literally about eight minutes from me. From you, I'm thinking about $1,000 and 16 hours on a plane. You weren't planning on going back, were you?

Richard L.
Plan on signing up for the world-wide 2020 DISTINGUISHED GENTLEMAN'S RIDEon September 27, 2020. This year it's a solo or pillion ride in dapper attire. Watch website at https://www.gentlemansride.com for details.


Online groily

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Re: Crankshaft shimming
« Reply #78 on: 19.01. 2021 11:00 »
One of these would save time and aggravation.
https://tinyurl.com/y47jeann

+1 for that or similar. Quite a bit of choice out there, Google is our friend. Something made of decent stuff takes a lot of the pain out of these jobs.
Going on price alone can lead to disappointment though, as the knife edges can deform (under even moderate loads)  or worst case bust off. DAHIK!
Even expensive ones do have a bit of a 'service life' it seems: theirs is a shitty job sometimes. My own SKF one is showing signs and has had to be 'dressed' (which doesn't do it any good)  . . . and that cost me an arm and a leg  . . .
Bill

Online RichardL

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Re: Crankshaft shimming
« Reply #79 on: 19.01. 2021 11:44 »
One of these would save time and aggravation.
https://tinyurl.com/y47jeann

+1 for that or similar.

Ohhh, I've got your "similar" right here (he said, gesturing below his belt).  *smile* ;) Planning on a video for the amusement of seeing me bumble, fumble and ultimately succeed with my puller.

Turns out this just became a busy work week, so moving much more slowly than I wished.

Richard L.

EDIT: I'm not rewriting the above, because it's accidentally pretty funny, having left out the word "bearing" before the word "puller."
Plan on signing up for the world-wide 2020 DISTINGUISHED GENTLEMAN'S RIDEon September 27, 2020. This year it's a solo or pillion ride in dapper attire. Watch website at https://www.gentlemansride.com for details.


Online RDfella

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Re: Crankshaft shimming
« Reply #80 on: 19.01. 2021 11:56 »
The easy way is to just prize it off with a screwdriver. Of course, if the bearing is a tight fit on the crank, then aggravation ensues. Blame the guy who fitted the bearing, as it only needs to be a gentle push fit on the shaft. There is no engineering argument for having a press fit, except maybe the manufacturer keeping tolerances wide to save on cost / rejects.
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Online RichardL

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Re: Crankshaft shimming
« Reply #81 on: 19.01. 2021 12:20 »
The easy way is to just prize it off with a screwdriver.

Not accustomed to you being sarcastic, RD. ;)

Richard L.
Plan on signing up for the world-wide 2020 DISTINGUISHED GENTLEMAN'S RIDEon September 27, 2020. This year it's a solo or pillion ride in dapper attire. Watch website at https://www.gentlemansride.com for details.


Online Greybeard

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Re: Crankshaft shimming
« Reply #82 on: 19.01. 2021 14:03 »
The easy way is to just prize it off with a screwdriver.
Or wood chisel?

Online RDfella

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Re: Crankshaft shimming
« Reply #83 on: 19.01. 2021 14:09 »
Not a question of sarcasm, Richard, more of exasperation. This subject has been discussed many times, yet people still struggle with that bearing when there is no need. If the bearing is tight (not all are) then destroy it if necessary to get it off, but then ease the crankshaft with emery tape until the new bearing is a sliding fit. End of problem. As stated, there is no engineering reason for the bearing to be tight other than keeping manufacturing costs down by having wide tolerances. Worry about the bearing not being tight? On Ford Zetec engines the pulley which drives the cam belt, waterpump, alternator, PAS etc is not keyed to the crankshaft nor is it on a taper - it's not even a tight fit. If you tilted the engine sideways without the retaining bolt in place, the pulley would fall off. It is retained (and, unlike a bearing, needs to contend with considerable torque) simply by the friction created by the retaining bolt. The cam sprockets are the same - and they're plastic to boot!
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Online RichardL

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Re: Crankshaft shimming
« Reply #84 on: 19.01. 2021 14:56 »
Don't want to argue too hard with RD, but am I the only one here that believes the main bearing inner race is intended as an interference fit?

Richard L.
Plan on signing up for the world-wide 2020 DISTINGUISHED GENTLEMAN'S RIDEon September 27, 2020. This year it's a solo or pillion ride in dapper attire. Watch website at https://www.gentlemansride.com for details.


Offline Seabee

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Re: Crankshaft shimming
« Reply #85 on: 19.01. 2021 16:10 »
Richard,

The short answer is yes. The only worry I might have in easing the crank surface to get a sliding fit, is the possibility of fretting between the inner race and crank. As RD stated, in most cases it's probably not a concern. Especially if the cush nut stays torqued. That said, I seem to be the guy referenced out side of "in most cases"...............
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Offline muskrat

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Re: Crankshaft shimming
« Reply #86 on: 19.01. 2021 19:56 »
G'day Fellas.
The proper bearing is a C3 fit requiring both crush on the outer and a light interference fit on the shaft to give it the correct clearance of the rollers. A loose (sliding) fit on the shaft will give the rollers just that little bit more clearance and allow the shaft to rock. I know were only talking minuscule amounts but at 50 times a second @ 3000rpm  *eek*.
The other consideration is if the cush nut loosens the bearing should stay put but if it does move it would be gradual. If the bearing is loose it won't take long to flop around like a prick in a shirt sleeve.
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Australia
Muskys Plunger A7

Online RDfella

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Re: Crankshaft shimming
« Reply #87 on: 19.01. 2021 21:06 »
Musky is right - but how many people buy a C3 bearing - or, indeed, do their suppliers even know what that is? Moral is, when using a bearing with interference fit, use a bearing with more clearance, when no or little interference, use a standard bearing. And do that cush drive nut up tight! Personally, I don't belive in this 65ft/lbs stuff. Unless you've got the cylinders off and jamming the crankshaft from turning, how do you achieve that? Restraining the engine sprocket means the cush drive is pushing against the nut you're tightening, making the actual torque applied anyone's guess. A 3/4" thread should be anything up to 400lbs/ft depending on the steel used, so I consider 65 extremely conservative.
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Online trevinoz

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Re: Crankshaft shimming
« Reply #88 on: 19.01. 2021 21:10 »
I ease the shaft for a nice fit and set the end play. When all is good, I use a drop of Loctite on the bearing.
I am sure that my bearings are standard.
Works for me.

Online berger

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Re: Crankshaft shimming
« Reply #89 on: 19.01. 2021 22:03 »
I made mine a gentle tap on fit and used Stanley knife blades to start it on removal then thicker knife edges  keeping them dead opposite , the secret is keeping it square to the shaft and trying not to damage the shim/shims like I did the first time *problem* *bash*