castle nut

SCOTCHERS · Oct 1, 2009

I have a PT 425 and my castle nut on my left rear wheel came off today. I got it in 2002 and run it hard though am surprised this occurred. Non the less, I called Keith at Power trac and asked the size and he told me it was a 3/4" 28 Thread per inch. Can't find it anywhere. Not even online. Every tractor supply, hardware store or Pep Boys or Salvo only have the 3/4" 10 or 16 and don't seem to think there is such a castle nut as suggested by Keith. Anyone know for sure? My PT's down and out and Keith say's he can't get me a part till next Tuesday or Wednesday. Any and all help would be appreciated.

Thanks

John

woodlandfarms · Oct 1, 2009

Have it made? Take a 11"16 down to a machine shop an have them cut it bigger. Temporary but workable...

BobRip · Oct 1, 2009

Count the number of threads per inch on the shaft or take one off the other motor and take it with you. 28 tpi sounds like a lot for a 3/4 inch bolt.

Gravy · Oct 1, 2009

SCOTCHERS said:
I have a PT 425 and my castle nut on my left rear wheel came off today. I got it in 2002 and run it hard though am surprised this occurred. Non the less, I called Keith at Power trac and asked the size and he told me it was a 3/4" 28 Thread per inch. Can't find it anywhere. Not even online. Every tractor supply, hardware store or Pep Boys or Salvo only have the 3/4" 10 or 16 and don't seem to think there is such a castle nut as suggested by Keith. Anyone know for sure? My PT's down and out and Keith say's he can't get me a part till next Tuesday or Wednesday. Any and all help would be appreciated.

Thanks

John

3/4"x28 sounds wrong. 28 pitch goes with 1/4", not 3/4". Even then it's a fine thread. At 3/4x28, the threads would look like hairs wrapped around a broomstick. I've had one of my wheel nuts off and I think I'd remember if it were that weird. I'd bet Keith's parts book has a typo. I'd buy one each of the 3/4"x 10 & 16 and see if either one worked. Don't forget cotter pins and Loctite.

I've got a busy day tomorrow, but if I remember I'll check mine.

Clarke · Oct 2, 2009

Get a thread gauge and check it.

sg

KentT · Oct 2, 2009

Clarke said:
Get a thread gauge and check it.

sg

Or, worst case, take one off another wheel and take it with you on your search...

SCOTCHERS · Oct 2, 2009

Sorry Fellas,

I asked 3-4x's then finally took it to John Deere. They measured it and it came up 1" x20 Thread.

Still it's impossible to find in Maryland.
Keith is having a couple sent but my PT is down and I need her for work.

MossRoad · Oct 2, 2009

That's an awful strange thread.

Call these people.
Welcome to Mid States Bolt Screw
I use them for all my bolt and nut needs. If it is made, they can usually get it.

DCWhitley · Oct 2, 2009

I checked my old Machinery Handbook and there is in fact a 28 tpi in a 3/4" diameter listed in their SAE Special Pitch Table, along with 14, 18, 20, 24 even a 32 tpi. American Standard Course Thread for 3/4" is the 10 tpi, American Standard Fine Thread is 16 tpi. Hope this helps.