Cracked 520H Seat Spring Pics

[WheelHorseVH 95]

Hey guys, I know this has been a somewhat known issue but I just found out I have a cracked spring on my 520H seat. Toro wants something obscene for them. I thought about putting a 2” compression spring between the big ends, anyone ever try that? Anyone have any ideas or a spare in good condition that you would sell for a reasonable price? If so please dm me, its kind of a critical part right now.
 

On a side note, my extremely limited understanding of metallurgy aside, I think this type of cracking on a thick metal “spring” is because something went wrong in one of the annealing processes and the pieces stayed brittle instead of malleable with memory. Or they simply undersized the metal even though it’s fairly thick. Or I perhaps I got oversized and need to listen to my wife and eat more salads. Either way, I’m going to stick to blaming bad metallurgy.

[mrc 727]

i must have one of those. let me check

[Ed Kennell 35,912]

I think I sold my last pair at the big show last year.     A-Z Tractor supply will have used seat springs.

[lynnmor 6,814]

When purchasing springs, be sure to check the hole center to center measurement, all models are not the same.  I did weld one of those springs to keep me going and it held up for quite some time till I found a replacement.

 

Those springs break because of metal fatigue and that poorly placed hole next to the bend is a stress point.  Your idea of adding a coil spring can only help but the ride will stiffen.

[ri702bill 7,373]

Good idea on the coil spring. You need to capture at least one end to keep in from walking out of position. Not much free travel there though before the coils bind (touch).

Did one on the 854 and it is adjustable....

 

 

[grinchsr 599]

If MRC does not have a spring I have a set down in Shelton.

[peter lena 8,098]

@WheelHorseVH  been doing this for years , / related  seat frame /  seat issues . typically , look at  what's there , duplicate it ? pick up a used part on line /  vendor . or  substitute ?  coil spring rubber  mount / stud , will often fit right into the existing  w/h fender pan mount . used industrial , sifter  pan spring  / mount , for my  set up . typically look at a problem , with how can I make this better ? purists can easily  find duplicates on line . like to improve on that . make it bombproof . look at coil seat spring  pictures , also improved my seat frame , mounting , for more room . pete    

 

[WheelHorseVH 95]

@lynnmor  I wish I had learned to weld in the past year like I wanted to do. I have a Craftsman welder but literally nothing else, so I will try to find someone to do it for me. @ri702bill I like that. I was thinking of exactly what you described, springs that are captured on one side by a bolt, preferably the top, and free to bounce on the other end, preferably the bottom. I like your setup though I was thinking of a fatter, beefier spring for the rear bolt.

 

@mrc @grinchsr, please DM me if you happen to find a spare set. Appreciate you guys looking.

 

By the way…all of this started because I wanted to replace my low back replacement seat with a high back seat with armrests, closer to OEM. Now let me tell you, my current seat is made by a company called Milsco and that seat is way the hell stronger than the metal springs on which it rides. What I did was look up a Milsco seat on Amazon and order it because the shipping was cheaper than other online dealers. Guess what happened? I got a knockoff delivered to me in a box that was so beat up that the mailman had to come knock and ask if I wanted it taken away immediately or inspect/return for myself. I obviously kept it.
 

When I opened it, it wasn’t a Milsco seat at all. Compared the material and design to my current Milsco and it was nowhere close. Thinner material, no alignment punch holes, and most of all no branding stamp like mine has. Surprise, surprise, right? They tell you in the one page Xerox instructions that came in the box to cut into the seat to insert the speed nuts to install armrests. No freakin thanks. I started the return tonight and will send it back. You might think that I learned my lesson from the Deestone Ags but I swear this time I have. 

 

 

[mrc 727]

i see where lynnmor says to check the hole spacing as not all are the same.  what are your dimensions?  i know i have some of those. just have to find them.

i could weld yours if you come up.

 

i have a gold horse head emblem too

 

regards

mike

[8ntruck 6,410]

If you have one of those springs that is not cracked, you could extend its life by polishing a small radius on the top edge of the bolt hole.  The polish operation is important, as grinding marks or file marks are also places that encourage fatigue cracks to start.

 

The square edge on the bolt hole is a stress consentration point - a 'break here' feature.  Polishing a small radius will remove the 'break here' feature and should increase the fatigue life of the seat spring.

[Lee1977 6,253]

On 4/24/2024 at 2:59 AM, lynnmor said:

When purchasing springs, be sure to check the hole center to center measurement, all models are not the same.  I did weld one of those springs to keep me going and it held up for quite some time till I found a replacement.

 

Those springs break because of metal fatigue and that poorly placed hole next to the bend is a stress point.  Your idea of adding a coil spring can only help but the ride will stiffen.

The center to center distance on 520 seat springs is 8". Older models are 7" center to center