520H drive kicks off after 1min of mowing

[Hayden 2]

Hello, 

 

I recently purchased a 520H and have started having problems with it. My dad and I took the mower deck off, cleaned it sharpened the blades and re installed and the tractor has worked well for about 5 mows. When mowing a ditch I realized my mower deck arm (not sure of the correct terminology) popped out of the slot and I wasn't able to pick it up anymore. Got it put back in, and went to go mow with it the next time. The grass was still slightly wet and it was a bit tall and I had a hell of a time because the mower drive kept kicking off. Had to hold the handle forward with my foot to finish the yard because we needed it mowed that day. The belt looked a bit loose to my untrained eye so I tightened it until there was no more adjustment but didn't seem to make a difference in the drive not kicking off.

 

Im going to search the forums more extensively but if it sounds like something obvious I would very much appreciate some help.

Thank you! 

[Ed Kennell 38,175]

You may try increasing the pressure in the PTO clutch.   You do this by removing the hairpin clip from the trunnion on the threaded rod that engages the PTO.

Then rotate the trunnion one turn clockwise as you face the end of the rod and re assemble the trunnion and clip. This increased pressure on the PTO lever may help it to stay engaged.

 

The other issue with the deck lift pin coming out of the slot could be a problem with the rear end of that lift bar being bent or loose in the bushings that support it in the tractor frame.  You would need to get under the tractor and determine if the end of the lift bar can be moved.  There should be very little side to side movement.  If the deck is not engaged in the mid attach-o-matic, correctly, this could cause the lift bar pin to exit the slot.   The VEE slot in the rod must be engaged with the large rod.

 

Go to our manuals section and download the operating manual for your tractor.     

 

to the 

[Lee1977 6,659]

If some one had the lift chain too short the hydro lift can bend or brake the lift rod. The deck should have a hole in the pin that lifts for a pin to keep it in place. There is a bushing and

c-clip on the lift side of the lift rod to hold it in the frame if it came out of the frame.

Sound like your belt is streched. There is one more thing that will cause the PTO to not to work. If the c-clip on the out side of the PTO pulley comes out you will not be able to adjust the PTO.  

Edited May 12 by Lee1977

[Handy Don 12,232]

2 hours ago, Ed Kennell said:

Go to our manuals section and download the operating manual for your tractor. 

Also your mower deck manual, @Hayden. 

The above comments are all on track, (especially the “V” tab on the deck frame rod that locks into the mid-hitch on the tractor not being engaged with the hitch lock rod).

 

BUT if that isn’t the cause, please also consider that some part of the lift frame on the mower deck is bent and misalignment is contributing to both the belt slack and the lift arm pin slipping out of the deck frame.

[Hayden 2]

 

 

[Hayden 2]

Found a few things out. Where the lift bar mounts it looks like the bushings are completely gone. The aft mounts on the mower deck are very worn even when the nuts are tight (one wasnt).

Not sure what that extra bar mounts to. Would like to get that figured out before I do anything. I looked through the manuals section and about like every other 80s manual I have dealt with its hard to find. of the 13+ pages of manuals over 50% are wiring diagrams and I didn't see anything akin to "85-90 wheel horse 520H operating manual". 

 

It would make sense to me that multiple bushings being gone and things being loose enough would cause the belt to not be as tight as needed causing the PTO to shut off. I imagine that is what the problem is. Would also be curious if we somehow had the chain too short as Lee suggested. Not sure what length it should be at!

 

Thanks everyone for there help and continued. help

 

[lynnmor 7,306]

Download the deck manual.  You will find some information in both the tractor and deck manuals.  Start by following the deck installation instructions.

[Ed Kennell 38,175]

OK Hayden,  thanks for the excellent vid, that helps a lot.

 

The worn or lack of bushings in the rear support rod of the lift bar is certainly part of the problem that is allowing the deck to drop.

The other thing that jumps out at me is the deep grooves worn in the deck carriage rod that hooks into the attach-a-matic.

That can also allow the deck to twist sideways and cause the lift pin to pull out of the slot.

The loose bar that you found may have been used in place of the chain at one time.  Or it may have been used for a snow plow lift.

The looseness in the rock shaft should not be a factor as it is connected to the deck with a flexable chain. 

That chain length should be adjusted so the rubber bumpers on the deck support frame just make contact with the foot rest boards when the lift is totally up. 

The unused vertical bar on the rock shaft is only used to raise a snow blower or tiller.

 

My conclusion is;

1. install new bushings in the lift bar support rod

2. your deck carriage is beyond repair  and should be replaced.    these are usually easy to find as the deck shells usually wear out first.

 

[Ed Kennell 38,175]

On 5/16/2024 at 6:02 PM, Hayden said:

things being loose enough would cause the belt to not be as tight as needed causing the PTO to shut off.

The tension of the belt is not a factor in the PTO disengaging.   A loose belt may slip in the rotating PTO but will not cause it to disengage.  It is a very easy procedure the increase the pressure on the PTO clutch plate.   Just pull the clip and rotate the trunnion one turn CCW.     It may help.   If the bushings in the PTO engagement lever are worn out, they may need to be replaced.

Edited May 23 by Ed Kennell

[Ed Kennell 38,175]

After watching you vid a few more times, I noticed a couple more problems.

1. the blade trunnion belt should be on the bottom sheave of the double pulley.  The PTO belt goes on the top sheave.

2. That long bent bolt is a problem if it allowed a gap between the chain and the lift bar.  That would put a twisting force on the lift bar that may have contributed to the wear on the bushings that support the lift bar.     I like to use a clevis to connect the chain to the bar to minimize the twisting.

3. I now see your deck does not have the rubber bumpers that should contact the underside of the foot rests.  Again, I would look for a new carriage assembly.  I probably have one that would fit, but the shipping would be terrible.

[gwest_ca-(File Mod) 11,045]

Have a model number and serial number for the tractor? It is 1990 or newer.

 

[NA73 70]

Hayden, any updates?

[Hayden 2]

Yes, I tightened up the carriage I saw was loose, went and got a new belt, and tightened the PTO clutch a few turns and the mower is working good now. Im going to look for some bushings for the lift rod mount points, I think that is the reason the lift rod fell out initially it has a lot of play. The new belt was pretty tight with the mule all the way in, and tightened up great with just a few turns. I think the old belt being very loose caused my problem but am still going to fix the lift rod mount.

 

Thanks for all the help!