I just replaced the bushings in my cooling fan assembly in the 27 to eliminate the excessive play. I re-assembled it all and the fan was locked up. I even tried removing the new felt washer and it is a lot better, but to me feels way too tight. What am I missing?
I have it assembled in the following order:
Fanshaft goes through two bushings in hub
It almost looks to me like I am missing a washer somewhere....
Does it spin freely by itself? I had to line ream one awhile back.
Maybe the new bushings are to tight.
Maybe they have to slightly reamed or faced off.
I re-assembled it without the cap that holds the felt washer and it spins nicely.
I did notice that the new bushings have a bit thicker shoulder on them - maybe I just need to take a little bit off the face......
Greg, I think your bushings are a tad too tight. I rebuilt one a few years ago and ended up using a very slightly worn shaft. It worked out great. I figured that when it starts to get a little loose, the new shaft should be about right. Dave
I rolled a piece of sand paper on a dowel just slightly smaller than the bushings and gave it a few turns. It worked fine for me.
I took it apart again and started to really look at the cap that holds the felt washer in place. When I tightened up the nut, this cap was binding on the bushing.
I took it apart again and when I looked at the shaft inside the assembly, , there is a small bit of the shoulder of shaft that sticks out of the bushing (on the threaded side)
The cap is supposed to have a small shoulder that allows everything to tighten up without actually binding up on the bushings. The cap that I have looks almost flat, so I added a thin washer between the cap and shoulder of the shaft (where the felt sits), installed it, including the felt, and it spins nicely. Looks like all this trouble was from that 2 dollar cap - I guess next order I place, this will be on the list....
Did you screw it together too tight? You run the center bolt in all the way till it bumps up then back off just enough to where it spins.Nut then cotter pin in place next.
Like everything else, .002" clearance.
And you need the excess shoulder sticking out of the backside of the hub. Don't plane that away because it keeps the backside of the pulley away from the arm.
You are simple threading it in too much. There is a reason there is a castle nut and the end is drilled. Run it all the way in till it bumps and squeezes the felt and cup washer, then back off just enough to where it spins free, put the nut on and pin it in place.
You are talking about the brass/oilite shoulder on the bushing right?
Mine is the newer fan shaft (27) - no hole in it for a cotter pin.....
I think that I tightened it up too much and distorted the cap the first time I assembled it.
Thanks for the input - you guys are always a great help.
As I recall, there is a shoulder on the fan shaft, which determines how far the fan shaft will screw in. Is it possible you may have a replacement shaft that was made incorrectly, or perhaps the shaft was altered for some other reason? I would recommend trying another fan shaft just to see if that might be the problem. I have a couple of NOS shafts around here, and would be happy to check one for you. I've rebuilt several of these units, and have never had the problem you have mentioned.
The shaft looks to be original and not altered in any way. There is a shoulder on the fan shaft that protrudes a bit out of the assembly - I believe that the center of the cap is supposed to tighten up against this shoulder, allowing the assembly to be tight, and spin freely. When I tighten up the assembly with the cap and felt washer, it binds up tight. If I install a thin washer on the shoulder of the shaft before installing the cap, it tightens up nicely and still spins freely. I have another cap at dads' house that I am going to try....
I even installed the old bushings again and it jams up tight, so I do believe that I am the cause of my own misery on this one.