# LT 1000 Vibration



## Noodler4631 (Nov 2, 2014)

I own a Craftsman LT1000 tractor (917.273381) 17.5 HP B&S, 42", Hydro Trans which I purchased new from Sears in 2004. The mower has worked fine (although the tranny is whiney) until 2 weeks ago, I started mowing, everything seemed fine, and after about 100 yards it started vibrating. Before I could disengage the blades and turn the tractor off - a loud BANG - the engine let go. 
I removed the engine and gave it to a co-worker who likes to "tinker" with such things and he informed me that the connecting rod and the casting that holds the main bearing had shattered into a dozen or so pieces.
I replaced the engine with a direct fit 19.5 HP B&S from Small Engine Warehouse, replaced both Drive Belt and Mower Belt (Sears Parts Direct) dropped the tranny and replaced the fluid in both the axle and pump even though they are supposedly "non-servicable".
The new engine started right up, runs strong and smooth, the tranny is almost silent now, is more responsive and the tractor seems faster, especially in reverse. When I engage the blades I now have a vibration, not as violent as the vibration before the old engine blew, but still noticable. I have been lucky enough to never have hit anything while mowing and am still using the same blades. Any help as to whats going on would be appreciated.
Thanks, Mike


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## jhngardner367 (Apr 5, 2011)

First,balance the blades,and while they are off,check the deck mandrels for excessive play.
Also,check the pulleys for being loose,bent,etc,and the belts for condition.Watch them,while they run,if possible.


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## Noodler4631 (Nov 2, 2014)

Thanks for the reply. I just checked the deck for level left to right and it is good then checked front to back and front is 1/4" lower than back as per manual. I checked blade height, left blade is spot on, right blade is within 1/16" (from blade to floor each blade end). I started mower in neutral with weight on the seat and released brake ... drive belt has minimal, for lack of a better term "flop" when running. I engaged the mower and the mower belt seems fine also (both of these belts are brand new). Shut tractor off, removed deck and checked all pulleys, spindles and blade mandrels, all look good, feel tight with no play. I also removed drive belt and checked all pulleys under the mower, again, all looks and feels well with no play in pulleys. Removed blades and checked balance, that too is fine.
I then installed old belts (drive & mower) reinstalled deck and started tractor ... same vibration when mower is engaged, also the old drive belt has the same amount of "flop" as the new belt.
As a last resort I'm going to get a new set of blades even though the old ones are balanced, I'll try anything at this point. Has me stumped and I refuse to take it to a mower shop ... that's not gonna' happen. Thanks again.
Mike


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## jhngardner367 (Apr 5, 2011)

Well.it all sounds good.
The only other thing I can think of that would cause a vibration,is if the PTO clutch has a worn bearing.


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## wjjones (May 28, 2010)

Are you using a cone balancer, or some other way to check balance? You would be surprised at how liitle it takes to throw a blade off balance.


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