20 HP Briggs Vanguard seized up after rebuild

Arwing64

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I had recently acquired a John Deere Sabre that had a blown 20 HP Briggs and Stratton Vanguard engine. Good engine if it didn't throw the connecting rod out the side of the block.

Anyway, I wanted to attempt rebuilding it from other existing parts I had from other Vanguard engines. I replaced the block, connecting rod, and camshaft. Everything was bolting together nicely until I went to tighten down the oil sump on the engine. When I tightened the bolts, the crankshaft would not spin at all. When the oil sump bolts were loosened a bit, it would spin freely like it normally should. It was as if the crankshaft was rubbing against something in the engine.
One thing I will note is that I did have to replace the oil seal and bearings on the flywheel side. I thought I had it pressed in far enough but I am not quite sure. I used a hydraulic press to achieve this.

All of the other parts are in good condition, but I am puzzled on what I can do to make it so the crank will spin normally. Can anyone help me? I can post pictures if you need them.
 

bertsmobile1

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The end float on a lot of these is set by the thickness of the sump gaskets
 

Tinkerer200

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The end float on a lot of these is set by the thickness of the sump gaskets

Yeah, you have to have a minimum of end play. Don't have a manual at hand to tell you what that is but I can send you one IF you like, address below. Always tap both ends of the crankshaft after assembling and then see if there is any end play. The minimum is about what you can feel by yanking back and forth on crankshaft. You often have to tape each end initially to get any play.

Walt Conner
wconner5 at frontier dot com
 

Arwing64

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As a matter of fact, then the sump is torqued on the engine, it doesn't have any end play whatsoever, probably because it is trying to squeeze the crankshaft ends between the top of the block and the oil sump.

Do you think a thicker gasket on the oil sump would help to mitigate this problem?
 

Tinkerer200

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As a matter of fact, then the sump is torqued on the engine, it doesn't have any end play whatsoever, probably because it is trying to squeeze the crankshaft ends between the top of the block and the oil sump.

Do you think a thicker gasket on the oil sump would help to mitigate this problem?

As Bert told you above this is the way the end play is adjusted. IT MAY be necessary to use two gaskets. Your must have a minimum end play to prevent damaging engine.

Walt Conner
 

Arwing64

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Thanks for the info! I will try adding thicker gaskets and see if it is still locking up. Hopefully this fixes my problem!
I will report back if it works or not.
 

bertsmobile1

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Thanks for the info! I will try adding thicker gaskets and see if it is still locking up. Hopefully this fixes my problem!
I will report back if it works or not.

When you get a full gasket kit they come with 3 sump gaskets of different thicknesses .
Not unheard of to end up with all 3 plus a left over.
If you look at the crank, it has a shoulder top & bottom.
You can measure it ( I use the DRO on the lathe ) then measure the 2 castings to the machined bosses the crank runs between.
While it is apart again also measure the length of the cam and the depth of the cam bushes to the case joint face.
I have seen a cam that was too long also bind up an engine.
 
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