MTD / Briggs engine pulley problems

[KE4AVB]

Glad it was Briggs it replaced as they could have used the Kohler screw which I am thinking is SAE 7/16 which would have been lucky away. I just hopefully straighten out the Briggs here where the installer reused the M10 from Kawasaki engine.

The spacer should have still been used or the upper pulley can get damage. How I know, it because I missed the spacer on a recent MTD belt change and bent it. It also might explain why the screw went AWOL as the installer couldn't fully tighten the screw.

One side note. I don't recommend using the rope trick on OHV engine due the possible valve train damage if a valve is open. As BGS suggested the strap wrench is preferred.

[lefty]

Never thought of that. Makes sense though. Thanks for the tip.

Yeah...the spacer is definitely missing. Using the part number in a web search, I'm able to get a better look at it. Looks like it's got a flange on one side that I assume faces down on the pulley side? With the unflanged end up top near the engine?

[lefty]

The spacer should have still been used or the upper pulley can get damage. How I know, it because I missed the spacer on a recent MTD belt change and bent it. It also might explain why the screw went AWOL as the installer couldn't fully tighten the screw.

I think that's it. The shaft is about 1/2 inch longer than the receiving portion of the pulley. Leaving no tension on the bolt. Must have just wobbled out at one point allowing the pulley to start slipping down. Who knows when it happened.

[Arkie]

Never thought of that. Makes sense though. Thanks for the tip.

Yeah...the spacer is definitely missing. Using the part number in a web search, I'm able to get a better look at it. Looks like it's got a flange on one side that I assume faces down on the pulley side? With the unflanged end up top near the engine?

Just some info from previous experience in that area.
I think you have this spacer configuration you describe above upside down. Look at the upper portion of the crank and you will see a taper that is for the spacer flange to be UP and the non flared side of the spacer to go towards the pulley.

Also if with no spacer the pulley was moving UP/Down by about a inch on the shaft when operating if it has the correct pulley. The same flange spacer was used on a briggs twin. Like KEV says usually what causes such, even though they left out the spacer is the crankshaft bolt was not torqued properly or may not have had the lockwasher and the bolt if torqued was not torqued against the lower OD of the pulley, just the end of the crankshaft. I seem to remember that most MTD's used a thick flat washer, lock washer and the fine threaded heavy grade bolt of about a grade 5 or grade 8 with no shoulder. Do not use a standard grade bolt because it might break off in the crankshaft. (and some of them bolts were different lengths, some had a shoulder and not full threads. I suspect you need the all thread type bolt and might be available at a Auto store or you might get lucky and find all the assembly mounting components with a used pulley on flea bay. (those pulleys are fairly common and used on several models and if you look at your pulley you might even see the MTD part number stamped on your pulley so as to compare with the Model parts list to see if Bubba installed the correct pulley during the swap.
You should be able to get all the part number from your MTD tractor model number because both the Briggs twin and the single cylinder OHV and the L-heads engine would use ALL the same components in that area, because I've interchanged them myself.

I would clean the crankshaft good and probably replace the pulley because the keyway in the pulley has been severely hammered and may have slack when installed onto the crank. Those NEW pulleys are expensive. (approx $60)
You can find several used pulleys on flea bay with careful shopping for around $20 with free shipping , but be careful and make sure you get the correct one, their are some on flea bay that usually have same part number (listed wrong) and are slightly different. If I don't need the pulley or part very soon I do a saved search on flea bay for maybe a bargain future price. (you will get a email heads up notice of a new listings if you select a saved search)

I also use little bit of anti-sieze on the crankshaft to prevent the pulley from seizing in the future. I've seen them pulleys rust to the shaft to where I had to sacrifice the pulley for removal. Not a fun job when that happens.

[KE4AVB]

I think you have this spacer configuration you describe above upside down. Look at the upper portion of the crank and you will see a taper that is for the spacer flange to be UP and the non flared side of the spacer to go towards the pulley.

Correct Arkie, The flare goes to the engine side; otherwise, it will split.

I also use little bit of anti-sieze on the crankshaft to prevent the pulley from seizing in the future. I've seen them pulleys rust to the shaft to where I had to sacrifice the pulley for removal. Not a fun job when that happens.

I wish Cub Cadet would use some anti-seize on the ZTRs engine's transmission pulleys. I have destroy quite a few of them just to get to the engine's oil seal or to remove the engine for internal repairs.

[lefty]

Thanks guys. I think a new pulley is in order because there appears to be some wobble on the old one. Maybe because it spent some time only partially on the shaft. I was concerned about runout on the crank but once I got the pulley off, I can clearly see it's on the pulley. Not to mention, like you said, the key is a little mangled and if I take any material off there will likely be some play.

[lefty]

This is funny....The other day, I asked the owner if he found any hardware in his yard like any bolts, nuts, etc.

He just sent me a picture of something he found about a month ago on the lawn.

[Arkie]

Yep, that is the flared spacer that goes on the engine crankshaft first above the pulley with the flare up.
It was taking a hammering from the pulley moving up and down when the crankshaft pulley retaining bolt was coming loose.

Most likely need two new belts also.

You would think that the owner/operator would have got a heads up that that was not a meteorite.

[38racing]

Got me thinking. I got a used pulley for my neighbour. I can't recall if there was a spacer. I know she doesn't use the mower often but I should check. I had a Murray with the spacer. I misplaced it. Briggs wanted $35. I made one from a $4 bushing.

[lefty]

Got me thinking. I got a used pulley for my neighbour. I can't recall if there was a spacer. I know she doesn't use the mower often but I should check. I had a Murray with the spacer. I misplaced it. Briggs wanted $35. I made one from a $4 bushing.

Did you have to machine anything or was it already kind of close?

You would think that the owner/operator would have got a heads up that that was not a meteorite.

It always amazes me. You hear it all the time. "That's what that bolt was!"
Owner also told me that there was some grinding and burning rubber smell for a while before the belt snapped but didn't think anything of it. I said that might have been a sign that things were not going well.