help with 1 blade cutting higher

got a fastrak sd that's several years old

a few weeks ago it was leaving uneven grass

assumed a bent blade & i had spares so swapped all blades but still uneven

thought i'd take deck off to examine & noticed the front left a-arm that attaches the deck to the body was broken, it was a clan break at the weld so i re-welded & put it back figuring that had to be the issue but still uneven

tires has equal pressure so got out the service manual to level the deck. after 2 hrs of no success i googled for a video & ran across a newer service manual where i noticed an extra step. my manual was missing step-9 but after leveling there was still uneven grass

i compared the blades tips & the center & right blade (standing in front of the mower) were perfectly aligned but the left blade was ~3/8" higher than the center on both sides of the blade

took the spindle off & spun it to verify no wobble. it looked good but i went ahead & ordered a replacement

inspected the deck while the spindle was off & it was flat & level

new spindle arrived today & i just installed it but that blade is still 3/8" higher. currently using 2 washers to bring left blade down to the height of the center blade

what am i missing here ?

Hard to say. Your obviously missing the answer.

I would first go back to the broken piece you welded and I would measure everything around it and compare to the opposite side. It seems odd that your weld did not fix the problem but I suspect it is something related to it. I would measure from the spindle bolt down to the ground on every spindle, an then back up to the deck.

I would also place a level across your deck just to make sure it is still square so to speak. There is no logical reason reason for the difference but by measuring everything, the problem should reveal itself.

Sorry your having difficulties. Sounds like me trying to figure something out. I suspect others with more experience will chime in, possibly with an obvious answer.

Set the deck level on some blocks and remove all spindles.
Measure the depth from the spindle mounting holes to the ground.
Good chance you will find the center has risen a bit.
Solution is big hammer & block of hardwwood.
If it is a 1/4 " thick steel deck then add heat.
Or make some 3/8" spacers to put under the other two spindles to raise them.

A regular problem with pressed decks

OTOH a lot of the older decks had spacers under the blades so if the blade is held in with a bolt, no worries.
If a nut just make sre you have enough threads to hold the blade securily

Was anybody else operating that machine that could have hit something and caused the broken hanger? It seems awful weird that one day it's cutting fine and the next day one spindle is three eighths of an inch off. I'd be suspicious that the deck took a hit and maybe has a little bit of a problem now. If some paint starts suspiciously peeling off your deck in funny places that would pretty much confirm it. I know at least one manufacturer that makes half diameter spindle width washers for the top of the deck so that after people have hit things they can change the tilt of the spindle.
Regardless of all the who knows what happened... if two washers between the blade and spindle brought it back in alignment with no vibration that's what I would do and wouldn't look back.

something slam underneath the deck and possibly bent the flat upper deck metal upward?

thank you all for the feedback

the deck above the spindle with issue was bent upwards at 1 of the 4 mounting holes

heated with oxygen torch & beat with 10lb sledge hammer 6 whacks, should of stopped at 3 as it bent easier than i thought

took a few iterations of back and forth to beat the deck where it needed to be & then the blades were finally lined up

you can see the raised section where the rust is surrounded by the red line in this image

That should do it. :thumbsup: Somebody had to hit something.

no doubt something was hit & hard to do that damage

but i'm the only driver, aside from my 4yr old who drives from my lap, been driving since he was 2

would have thought a hit that hard would be more memorable

the deck is suspended on 4 corners by chains so there's lots of play in its movement

no worries though, it's cutting properly again

thanks again for the input

jakespeed said:

thank you all for the feedback

the deck above the spindle with issue was bent upwards at 1 of the 4 mounting holes

heated with oxygen torch & beat with 10lb sledge hammer 6 whacks, should of stopped at 3 as it bent easier than i thought

took a few iterations of back and forth to beat the deck where it needed to be & then the blades were finally lined up

you can see the raised section where the rust is surrounded by the red line in this image

View attachment 29496

Click to expand...

Hitting it with a bigger hammer usually fixes it quick. :thumbsup::laughing: