JD 40 Fan Belt Replacement

saxnbees · Sunday at 11:20 PM

I am not sure what you are suggesting. The problem is that I cannot turn the nut. It is frozen to the shaft on which the fan assembly is mounted. It is likely 40-50 years if not longer since the nut was turned and has rusted to the shaft. Unfortunately, everything is pretty tight so there is not much room to apply penetrating oil. There is also almost no threads exposed to apply oil to.

I am getting closer to your previous suggestion where I would try to replace the belts without removing the nut. Then I would need to adjust the belt tension with a pry bar and come up with a way to hold it in position since the nut cannot be tightened either.

Fuddyduddy1952 · Monday at 12:09 AM

Maybe this will help(?).
Years ago I needed to replace the clutch fan on my F150. The nut was 1 5/16" from memory (large). I tried everything. Then remembered I had an air chisel. It was right hand thread so I put chisel on nut flat right at edge as shown. Bad drawing but you get idea.
It was easy, apparently the vibration spun it off and as it turned put it on the next flat as it turned.

saxnbees · Monday at 11:56 AM

Good idea if I can get the chisel in there. Do you remember whether there was any damage to the nut? I have done similar with a screw driver and hammer in the past.

I think the trick is that there is a lot of instantaneous power released every time the hammer hits....more than you apply with a wrench.

Thanks for the suggestion.

Fuddyduddy1952 · Tuesday at 10:22 AM

I used a chisel that needed sharpening and no damage to the nut. In my case the new clutch fan came with new nut anyway.
It worked well for me.

saxnbees · Tuesday at 10:34 AM

Thanks for the feedback. I am at the point where I am going to try replacing the belts over the fan without removing the nut. But that may not be possible for the generator belt as it is much smaller than the fan belt. When I bought the belts, I never thought this would be such a difficult task!

beenthere · Tuesday at 10:37 AM

Fuddyduddy1952

I'm thinking this '50's model 40 doesn't have a clutch fan and new parts are not available. Finding a new nut to fit the threads might also be a real problem. Risk of breaking the cast frame that holds that fan axle in place may be found in a parts house, and might be worth a search before risking breaking something.
I'd be trying continued use of a good penetrating oil (something like kroil or a new one I've found to be the best available, is "blue creeper" from Logrite)

saxnbees · Tuesday at 3:20 PM

Update. Decided to just try and remove the belts from over the fan. That was a success. However, there is one tight spot that has become a problem in installing the new belts. There is a spring loaded shaft that is pushed into a couple of detents on the crankshaft for crank starting the engine by hand. The old belt fit through the gap between the start shaft and crank pulley because the belt was worn so thin on top. However, the new belt is much wider and does not want to go through the gap.

Any ideas out there? Can the spring loaded starter be removed easily....or pulled back somehow?

saxnbees · Tuesday at 3:36 PM

I think I just figured out the starter issue. Apparently this type of hand starter only exists on the tricycle model of the JD 40. There is a spring clip that holds the starter in position. Pop that off and the starter can apparently be pulled back out of the way or maybe removed. I may not be able to put it back once it is off because it is tight in there....but when will I start it by hand anyway? I have no clue where the hand crank is....

beenthere · Tuesday at 6:35 PM

Hand crank assembly from jd parts, and hope you are zeroing in on the right solution.

https://partscatalog.deere.com/jdrc/sidebyside/equipment/2803/referrer/navigation/pgId/1853358

Fuddyduddy1952 · Tuesday at 7:11 PM

beenthere said:
Fuddyduddy1952
I'm thinking this '50's model 40 doesn't have a clutch fan and new parts are not available. Finding a new nut to fit the threads might also be a real problem. Risk of breaking the cast frame that holds that fan axle in place may be found in a parts house, and might be worth a search before risking breaking something.
I'd be trying continued use of a good penetrating oil (something like kroil or a new one I've found to be the best available, is "blue creeper" from Logrite)

I agree Kroil or good penetrating oil. In my case with air chisel it was super easy after hours of trying everything imaginable. I wasn't using lots of pressure either and just the vibration and that angle was enough. Once started is all that's needed.
Like everything, use your own judgement.