35 HP B&S Commercial Vanguard Engine-Need Guidance!

[allfritz123 5]

Thank you for sharing the repair manual (272144) for this motor gwest_ca!  I really appreciate getting this information but I still can't figure out what is going on with my 6134787-0048-E1 35 HP B&S Engine.   The PTO seal in the crankcase cover on the protruding crankshaft started leaking very badly and it looks like some kind of shimstock (best way to describe what I see) came out from internal and has caused the seal to leak as it lodged across it.  It is a very thin copperlike colored material which appears to come from inside the cover somewhere.   I removed the seal and I can find a few more pieces of this very thin metal (shimstock for lack of a better word) and used a pick to pull out some pieces.   I can't see anything in the repair manual or even the parts manual which shows any such shimstock like material being used anywhere.

 

Did they use this to shim out the PTO bearing to make sure it was tight on the shaft?   At first I thought it was a speedy sleeve material but that is the thinnest speedy sleeve I have ever seen.  It definitely has a shape to it as side edges are nicely squared on the broken pieces.  Anyone run into this and what I am dealing with before I remove the cover?  Unfortunately I didn't take a picture yet as my phone battery had died!  

[gwest_ca-(File Mod) 10,496]

Please check your model number

6134787-0048-E1

[kpinnc 10,720]

On 9/15/2022 at 9:28 AM, allfritz123 said:

Did they use this to shim out the PTO bearing to make sure it was tight on the shaft?

 

I can't be certain with the 35hp, but all the "small block" 14-23hp Vanguards use steel shims to set the crankshaft endplay. 

 

If you blew out the PTO seal, I'd check the crankcase breather first. If it's good, look at the valve cover gaskets. The part of the gasket between the bore and pushrod galley is very thin, and can blow out. If that happens, you are venting pure combustion into the crankcase. My first 23hp did this exact thing, and it blew oil all over the place. 

[allfritz123 5]

On 9/15/2022 at 8:58 AM, gwest_ca said:

Please check your model number

6134787-0048-E1

Yes I had a typo moment!  it is 613477-0048-E1.

[allfritz123 5]

5 hours ago, kpinnc said:

 

I can't be certain with the 35hp, but all the "small block" 14-23hp Vanguards use steel shims to set the crankshaft endplay. 

 

If you blew out the PTO seal, I'd check the crankcase breather first. If it's good, look at the valve cover gaskets. The part of the gasket between the bore and pushrod galley is very thin, and can blow out. If that happens, you are venting pure combustion into the crankcase. My first 23hp did this exact thing, and it blew oil all over the place. 

Thanks!  I will look into that.  I wonder if these combustion gases could dislodge that shim material? It certainly is a weird environmental friendly crankcase breather with 2 hoses leading out to atmosphere.    I just find it coincidental to find that shim material across the seal and oil leaking out rapidly.  I don't see anything in parts manual or repair manual referencing shimming out end play or evem selling a shim stock kit.  Not sure if special shims or what would hold it in place to remove end play.  I didn't see anything to indicate how it could be held in place and the edge looked square and in pieces and almost conforming to the shaft circumference.  The pieces I find are measured in thousands in thickness.  I think there still is more beyond the seal and I will have to remove cover in order to pull them out from under the cover edge.  Everything in the engine seems tight.

[RED-Z06 2,118]

Check for crankshaft play...thrust (in/out) and shear play (90⁰ to the case).  You'll feel a very small amount of thrust but you shouldnt feel it shear up and down 

[allfritz123 5]

I did check vertical and horizontal play on the crankshadt and I don't feel anything noticable. I guess I could put a dial indicator onto confirm but it doesn't feel like anything unusual shear or thrust.

[allfritz123 5]

I replaced the crankcase cover (and oil pump) as you can't buy it separate.   The main crankshaft bearing (a thin copper bushing) cant be purchased separate either.   It is mounted in the aluminum cover.  The material I found was this bushing.  I also replaced the seal.  The reason for the failure is an overtightening of the drive belt on the engine.   In a farm application, elevating your grain auger to its extreme height caused the grain auger drive belt to get excessively tight and very quickly took out this bushing while running.

 

The problem was solved and it worked for a number of hours.  It was very cold and I used the engine. I have a different problem and will now have to do a compression check. I had limited power and i was getting oil leaking excessively out of the crankcase breather. I will have to take kinnpc's advice, check compression and check for pushrod galley and bore compression leak.  I am hoping this can be ascertained by running a compression test.  

[kpinnc 10,720]

The 35hp Vanguards have a different design from the 14-23hp, but the latter did have some issues with thin sections of the head gaskets failing. I believe this was corrected in later models. 

 

Given the huge side loads on applications like zero turn mowers (a primary user of big block Vanguards), I'm surprised yours had issues. Though they do use bushings, the crank journals are huge and specifically overbuilt supposedly to support those side loads. 

 

The 14-23hp "small block" twins also had a tendency to have issues with the sump cover gasket. Also corrected on later models.

 

One thing to consider: if the bushing on the PTO side was worn, then the flywheel side has to be as well.