450/451 snowblower fan spline repair
 

I created this thread to show how I repaired the stripped splines in my 450 snowblower fan. I wasn't about to spend $160 on a new fan when I could respline this one for about $15. I guess if you had to pay a machinest to do the work your cost may be a bit more.

I started by purchasing the correct 13 tooth 7/8" ID splined coupler. See the link below.

http://www.surpluscenter.com/Power-T...413-1-1392.axd

Next, the remaining splines and some extra material need to be bored out of the fan so the new splines can be pressed in and welded in place. I bored the fan hub to 1.0625 ID. That is the difference between the OD of the fan hub at 1.250 and the ID of the splines at .875.

http://i1094.photobucket.com/albums/...ps0a4d2e93.jpg

http://i1094.photobucket.com/albums/...ps580aa4bd.jpg

This is where I'm at now. I will finish with the repair tomorrow morning.

I forgot to mention that I bored the hole 1.250 deep and it cleaned out most all of the splines. This is also the length of the splines on the gearbox shaft. This must also be bored on center so you don't have any vibrations.

Nice job! :beerchug:

Here it is all ready to weld. Turned the coupler down in the lathe for a tight press fit into the fan. I also added a chamfer on the fan hub so I can fill with weld and grind it flush.

http://i1094.photobucket.com/albums/...ps074232ea.jpg

http://i1094.photobucket.com/albums/...ps7275f06d.jpg

Great idea ! It's just so sad that u wont see any of that to show it off. Mayb while u r doing all that work to the fan u could check it for balance, it may have been what started the whole problem. Dave

I think the main cause was that the gearbox shaft was not set deep enough into the fan splines. There is alot of in and out adjustment for the gearbox and you could tell only half the spline depth was engaged. I'm also thinking that the PO engaged the PTO at full throttle and not at idle.

This is the finished fan after welding. Looks good I think. Now I just need to install it in the snowblower and try it out.

http://i1094.photobucket.com/albums/...psfc759430.jpg

Great job!:beerchug:

Nice job on the repair!

"Looks good I think." That is way better than good! That is as good as it get's! Outstanding repair!:beerchug:

Excellent work!

I know this is an old thread, but I have the same situation. I am only able to find the splined coupler with 1 1/2 inch OD. Any thoughts on where I can find the 7/8 13 spline with a lesser OD, or did you buy a larger one and turn it down?

Did you try our Sponsors Patton or Houtz ???

I believe you will need to use the 1.5” OD coupler. This will need to be done by a machine shop. You have to bore the old splines out of the fan and turn the OD of the coupler down to press into the fan ID.

I have take the gear in the chaincase of snowmobile artic cat, same spline
but need grinding outside and the thikness it's smal, may be 3/4 , 7/8 but
it's one possibility , i have repair my 451 with that .
I speak in french apologize for my english !

Looks good. All the more reason I need a mill/lathe :D

spline repair
 

I repaired my splined shaft and it just broke again .It lasted maybe 2 winters. Is the splined shaft you used hardened and where did you get from .. Mine came from surplus center in Lincoln NE ..It surely should last longer ..what did do wrong


thanks