1951 Ford 8N Flywheel Cracks

[grange37]

Hi everyone,

I have a 1951 Ford 8N with 4,500 hours. After the solenoid shorted out causing the starter to slam into the flywheel with a hard clunk, I removed the starter to replace it and view the condition of the flywheel. I found that the flywheel has visible cracks along where the ring gear attaches.

I only use this tractor a handful of times a year for joyrides and occasionally for pulling a trailer. I do not know if these cracks are new or if they have been here for years. Is it possible that the cracks are a result of the started slamming into the flywheel?

My main question is whether the tractor can be safely operated like this, or if it need to be split and have flywheel replaced? Unfortunately I'm 300 miles away from the tractor and wont be able to get any more photos or diagnose further. Not sure how deep or far the cracks extend, or whether they're isolated to this one area.

Any advice or second opinions are greatly appreciated! Thanks!

 

[used red MN]

I found that the flywheel has visible cracks along where the ring gear attaches.

Hello grange, welcome to YT! I’m not a Ford guy so maybe this is a legit common problem on those tractors. To me it looks like what you are showing may be oil and dirt on the surface mimicking the appearance of cracking. Did you attempt to wipe the area to see if they would simply wipe away?
Looking closer, this crack (photos) on the chamfer might convince the rest of the crop is real. If it is cracking I don’t think you’re responsible for the normal cause of cracking in a flywheel like this. If you were that paint you see in photo 1 would not be present because if you slipped the clutch enough to create enough heat to cause those cracks that paint would be burned away.

 

[grange37]

Thank you for the reply! It very well could be just dirt and oil. I did not attempt wiping the area and only noticed the "cracks" after I had left and looked closer at the photos. What makes me think they might be real is how they are clean lines and branch off both horizontally and vertically. In theory if they were real structural cracks, do you think it would it be unsafe to run the tractor in this condition?

 

[Hobo,NC]

"unsafe to run the tractor in this condition"

It’s the norm to see heat cracks where the disc runs on the flywheel. Your cracks I dunno I will say cameras have gotten good I spec in the past we did not see those cracks.

 

[Kirk-NJ]

If it were me I’d split it for closer inspection. Got some laying around if you’re close to NJ and need one. You can have it if I have the correct one. Your ‘51 should be side dizzy unless engine has been swapped

 

[Eman85]

Clean it

 

[Farmalldude45]

Hi everyone,

I have a 1951 Ford 8N with 4,500 hours. After the solenoid shorted out causing the starter to slam into the flywheel with a hard clunk, I removed the starter to replace it and view the condition of the flywheel. I found that the flywheel has visible cracks along where the ring gear attaches.

I only use this tractor a handful of times a year for joyrides and occasionally for pulling a trailer. I do not know if these cracks are new or if they have been here for years. Is it possible that the cracks are a result of the started slamming into the flywheel?

My main question is whether the tractor can be safely operated like this, or if it need to be split and have flywheel replaced? Unfortunately I'm 300 miles away from the tractor and wont be able to get any more photos or diagnose further. Not sure how deep or far the cracks extend, or whether they're isolated to this one area.

Any advice or second opinions are greatlyI appreciated! Thanks!

Where is the seam between ring gear and flywheel? That looks suspiciously like it could be the seam, but I have no explanation for the irregular, ragged look. Good luck with it.

 

[Jim L WA]

What I don't understand is, why would a shorted solenoid cause the starter to slam into the flywheel any harder than when the starter button energizes the solenoid?

Oh, I guess it happened while the tractor was running?

 

[Duner Wi]

Here is photo of my 9N flywheel for comparison.