Fan movement, a problem?

[L head fan]

I have an 18.5 inch 4 blade fan (generator mounted type) on my fresh rebuilt 8BA. Fan blade will "shuck" in and out on the shaft with approx. 2-3 lb applied force. (moves approx. .030 axially)...Is this typical, or if not, whats the fix? I sure don't want to put it thru the new $400+ radiator when I break it in!
Thanks for all responses!

[ken ct]

Dont understand where it could move,gen mounted fans are the blades are rivited to the hub stub,how can it move. its bolted to the fan pully??? ken ct.

[bbrocksr]

Originally Posted by ken ct

Dont understand where it could move,gen mounted fans are the blades are rivited to the hub stub,how can it move. its bolted to the fan pully??? ken ct.

Endplay in the generator front bearing.
Bill

[ford1]

generator armature shaft moving in and out is also my guess, there should be a washer on the shaft that takes up the end play when the front of gen is bolted up, i would fix that problem

[flatheadfan]

Some of you may have read this before on another form but it also fits here so.......

I have seen this several times. Usually, after a backwoods rebuild job. The source of the problem is the front bearing and its' associated shims. The bearing rides on a shaft that should be "staked"(ie: centered punched) under the bearing. This prevents bearing movement on the shaft.

The second culprit are the washers in front of the bearing and behind it that act as shims and dust seals. Things are a little crowded but there are two felt washers and four thin washers, Two with a large holes and two with smaller holes. Everything is held in place with a snap ring. However, the sequencing is important. If any of the washers are left out or the snap ring is missing or things are mis-assembled you will have shaft movement with observable fan movement.

Is it a dangerous situation? I don't think it is or lets say, I haven't seen any problems. When running, the belt usually keeps things in somewhat of an alignment. However, shaft wear is greatly accelerated and will chew-up the brushes quickly.

But first, before I started to tear down things I would check the mechanical condition of the pulley assembly is its' attachment to the generator.

Hope this helps.

Tom

[L head fan]

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Sorry- my bad description causing some confusion...Fan assy actually separate from generator.
Fan assy consists of fan with hub/pulley rotating on solidly mounted shaft. This assy is attached to the generator mount, and has up/dn adjustment.
Also, the hub looks like it may have oil lube plug.
THANKS!

[G.M.]

That's the 47 type fan. Also has bearings. .030 is slightly less than 1/32". You need some clearance. A .020 shim washer would give you .010 clearance?? G.M.

[G.M.]

When the engine is running at a faster speed above idle the water pump shaft and pulleys on 32 to 48 stock pumps move forward from centrifical force and stay forward until idle speed when the seal spring pushes them back. I don't know the effect of the fan blade whether the shaft in that type fan wants to move from centrifical motion or the action of the air on the blades? Take a look and see what happens. In any event I don't think the shaft is going to have constant movement in and out when running. It may move one way or the other as the speed is increased and stay there check it out. G.M.

[L head fan]

Thanks everyone for the input. I'll have another look at it!
Dennis

[columbiA]

If fan wobbles on 32-38 generators,there is a threaded collar that adjusts the tapered roller brg on front of gen.