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: