Briggs 3HP with excessive crank endplay

[creia]

1977 Briggs 3HP, "Koolbore", horizontal shaft
M - 80202 T- 0547-01 C- 77052501
I knew it was going to be alot by the "clink-clink" sound I heard when I moved the crank back and forth. Today I actually measured it. It turns out to be .023"

Briggs manual states that crank endplay should be .002-.008" for this engine.
My Questions:
Just how big a deal is excessive crank endplay? (Especially this much)?
What would happen (damage?) if I did nothing and just ran it this way?

I have the Briggs Shim-endplay # 220624 part on order and coming this week. My understanding is that you install it, then add additional crankcase cover gaskets as/if needed to achieve the desired .002-.008", is that correct? Has anybody had experience doing this and can pass along some words of wisdom to this garage hack ? I notice that the shim has a lip around the hole on one side- does that side go against the crank gear?
As always, thank you.
Michael

[bgsengine]

1977 Briggs 3HP, "Koolbore", horizontal shaft
M - 80202 T- 0547-01 C- 77052501
I knew it was going to be alot by the "clink-clink" sound I heard when I moved the crank back and forth. Today I actually measured it. It turns out to be .023"

Briggs manual states that crank endplay should be .002-.008" for this engine.
My Questions:
Just how big a deal is excessive crank endplay? (Especially this much)?

Depends on the application it is being used in really... But either way that would be pretty nasty , especially if the crank was being side loaded (clutches, high belt tensions, water pumps, generators, and so on - more so because that much end play would screw with the attached equipment alignment..)

What would happen (damage?) if I did nothing and just ran it this way?

aside from the aforementioned line-up issues throwing belt or chain, pulleys rubbing in guards, stuff like that) you're also going to have balance issues and side stress on the rod, plus additional peening and rapid wear on the thrust faces of the block and side cover. - If it absolutely must run, I might let it go out the door with the advisory that it needs to be back ASAP for short block or repair/replacement as I would not guarantee it does not grenade internally at ANY TIME.

I have the Briggs Shim-endplay # 220624 part on order and coming this week. My understanding is that you install it, then add additional crankcase cover gaskets as/if needed to achieve the desired .002-.008", is that correct?

Correct , however depending on thickness of shim, you may not need any additional gaskets - The trick to it is, you install side cover *WITHOUT* gasket and just tap it down in place, install 2 bolts either side of crank in a line and torque them VERY LIGHTLY (no more than 5 inch lbs, you can't even FEEL that much torque - just a tad over finger tight, not even enough to compress a split lock washer) then tap lightly on everything towards the flywheel side and then loosen bolts (even finger tight can flex the cover) and measure any gap in the side cover to block - If your gap is less than .013" then you should not need extra gaskets, if it is greater, you'd have to figure how much shimming gaskets you need, and if the gap is less than .0015" then you will need to figure out how much more shimming to add to the crank to get a gap between .005" to .013" before the gasket. Then you can assemble with gasket and be fairly sure you'll have correct end play after all is said and done.

Has anybody had experience doing this and can pass along some words of wisdom to this garage hack ?

Oh OK, I already posted my procedure just above..

I notice that the shim has a lip around the hole on one side- does that side go against the crank gear?

Nope- You want the shiny smooth face of the shim against the crank gear (which should also be nice and smooth), so the lip side would go to the cover (Lip should help align shim with bearing journals so the shim won't wear into the crank) - Helps to tack it in place on the crank cover with a dab of grease.

As always, thank you.
Michael

Hope that helps.

[creia]

Thank you very much Brian.
I will report back with results after I install the Briggs end play shim.
Michael

[Arkie]

Just some general info about what I do about small engine crank end play
I most generally measure the end play on small engine crankshafts before I remove the side cover.
I've made a steel plate that I can bolt to the side of aluminum engines so as the dial indicator magnet will attach good.
I've seen some spec'd at .005-.030 and the ones that I can take to minimum W/o the sump gasket I use Yamaha bond 4 and no gasket. Briggs has different thickness of gaskets but most generally the thin one starts out at .023 area.
I've had to shim a few even w/o the sump or side plate gasket. I have metal hole punches and make my own steel shims.
I've heard some Briggs engines with excessive crank end play have a slight knock due to such.

[creia]

Update:
Success!
The Briggs endplay shim came today. After I installed it on the crank (I see NOW what you meant about the direction to mount it Brian!), I found that if I used the standard .015" sidecover gasket and added a .009 sidecover gasket my crank endplay ended up a .005" which is right at the middle of the Briggs accepted range.
Michael

[bgsengine]

Excellent! Glad you got it resolved.