stripped BX 60" deck blade bolts

[radioman]

My BX24 60 inch mower deck had a couple bolts stripped and spindles threads was ruined. I think i got a little overzealous :ashamed: with the air impact when tightening them since last summer the blades were spinning and not cutting from one of them. I had a bear of a time trying to take them off last weekend when i was about to take blades off to sharpen them. I was able to get the bolts off by reversing/forward many time to get the stripped threads loose enough to back bolt out- but i was nervous about needing a new shaft and rebuild the spindles. Since the dealers were closed over the weekend, i waited till monday to pick up new bolts and yesterday finally worked on it. i had to retap the spindles and if anyone needs to know what tap you need its M12 - 1.25 . got one spindle cleaned easily - but the middle spindle was a bear. took me over an hour to tap it. it must be high speed steel or something as it was really hard to run new thread. used whole quirt can of oil and i was nervous about breaking the tap as it was really twisting as i was turning it when trying to go a tiny 1mm of a turn or so. i had several pieces of metal fragments come out as i air cleaned it out - but it was finally done and i was able to test mow it last night at 9pm jand so far so good

So - lesson learned - if the blades werent holding anymore and not cutting right - its possible the bolts were either worn out or stripped and threads is trashed a little. this time I hand tighten them instead of using impact. Ill still use impact to take them out , but will always hand tighten the bolts.

 

[skipperbrown]

There should be a couple of concave washers you put on the shaft counterpoised after the blade goes on. These act as lock washers to keep the blades/nuts tight and not allow the blades to slip. If you have them, replace them as they are apparently worn out. If you don't have them, get them. These washers are what do the bulk of the holding so you don't have to torque the nuts down to the point of stripping. That must have been a job!

 

[ovrszd]

Good point skipper. That was my question? Should be washers there. The bolt doesn't have to be very tight.

I truly can't remember the last time I sharpened my mower blades. I use these predator blades I get thru JD. They are extremely hard. Replace them when they actually wear thru the serrated lifts and they become ineffective.

Sharpening, if needed, should always be done with something mild like a flapper wheel. A grinding wheel will heat the cutting edge and remove it's temper. Then you get the joyful experience of frequent sharpening.

Glad you got your problem repaired. Much patience was needed I'm sure.

 

[Mowbizz]

Hand that happen to me last year. Just one bolt though. I should check those washers too...this will be my next job between raindrops.
I could not find one of those taps anywhere and finally found that a Grainger store had them and i had to drive 2 hours to get it. Problem solved but not looking forward to this seasons surprises!

 

[Dave M7040]

There should be two stacked spring washers on the wider BX mowers.

The proper term for these washers is "BELLEVILLE WASHERS."

The bolt torque is up to 86 lb ft

Dave M7040

 

[radioman]

There should be two stacked spring washers on the wider BX mowers.

The proper term for these washers is "BELLEVILLE WASHERS."

The bolt torque is up to 86 lb ft

Dave M7040

Mine came with one cupped washers and one none slip washer.good point though... I should replace the cupped washers.. And thanks for proper torque specs. I'm pretty sure that's why I'm having problems last summer. Weak cupped washers plus over tightening. Time to hit online ordering....

 

[Dave M7040]

Mine came with one cupped washers and one none slip washer.good point though... I should replace the cupped washers.. And thanks for proper torque specs. I'm pretty sure that's why I'm having problems last summer. Weak cupped washers plus over tightening. Time to hit online ordering....

Be careful with any mower. Some have reverse thread bolts for the blades.

Re tapping a reverse thread hole is not simple.

Dave M7040

 

[radios1]

you should use tapping fluid, not oil for tapping. many places sell it for threading pipes..

 

[Mowbizz]

Serviced my deck and installed it for the season. No problems with the blade bolts and my bellville washers were in good shape!
Hardest thing was getting a new grease cartridge in my Milwaukee gun...what a pain.
Maybe someone can post the correct way to change the grease cartridges? I must be doing something wrong.
Haha...never mind. Just looked it up on YouTube and I was doing it completely back asswards....didnt know the thing unscrewed from the front...duh.

 

[radioman]

Be careful with any mower. Some have reverse thread bolts for the blades.

Re tapping a reverse thread hole is not simple.

Dave M7040

yeah -- when i went to the store to get the tap - they had a sizing chart with threads and bolts with labels so i checked the threads with mine bolt i brought in-- its a normal thread not reverse so im good there