Fan reassembly

[Petrah Phyre]

Just performed a clean up of my '26 fan assembly. I used moly bearing grease. Correct or no? My rear cap did not have a felt washer underneath. Is that required? Seems like it should help with grease loss.

[Humblej]

Sean, Ford used oil in the fan. The threaded hole on the fan is for the filler plug, many replace it with a zerk fitting and use grease. Both oil and grease work out of the rear of the fan shaft and make a mess on the inside of the hood. The felt washer is the seal, essential when using oil, but it slows down the grease leaking out too.

[TXGOAT2]

I like moly grease, especially for chassis lubrication, but it might not be best for a brass bushing, since it has sulphur or sulphide in it. (MO2S (?) I'd use red grease and a felt seal. The best solution is the ball bearing hub.

[Mark Gregush]

Stick with oil. Grease just does stick around between the shaft and brass bushings. Some use motor oil, me and others, a heavier lube like 600w or even chainsaw bar lube. I tried grease, my fan let me know it did not like it!

[TXGOAT2]

Ford used oil lubed fan hubs up to about 1950.

[Petrah Phyre]

Thank you for the insight. Looks like it's coming apart again. Good thing I like to turn screws. I will get the felt and switch to oil.

[Humblej]

Order the oil filler plug also.

[Harry Lillo]

I have a question?
If all Model T fan hubs were to be oiled why is there a drilled hole from the back of the hub shaft to a
the center of the shaft?
I was working on my small diameter fan pulley last night and was contemplating how it would be lubricated
with grease. Another parts shaft from my inventory had an interesting grease cup on the rear.
It was a locking nut/ grease cup combination.
Very clearly, this unit was designed to use grease to lubricate the shaft.
Harry Lillo
Calgary

[jab35]

The early versions had a grease cup at the end of the fan axle, later '26-7 for sure had the oil plug. I use chainsaw bar oil, fwiw. jb

[Mark Gregush]

Good question Harry. Could it have to do with where the grease would come out on the shaft or how often that style required greasing? The hole where the grease comes into the housing is in between the bushings on the early style with the grease cup, along with the front not being sealed, so grease can flow better to the front.
The later style redesigned hub, the grease would fill the cavity behind the bushings and would require more turns of a grease cup to get grease to the front bushing, so Ford went with oil, felt seal at the rear and paper gasket on the front in an attempt to keep things lubed and cleaner. (?)
Guess Ford could have kept the grease cup on the shaft like before, but this could have been a cost savings to just use oil and simple plug.

[Humblej]

Harry, this was never an "all model T's" discussion. Original post is in regards to the 26-27 fan. There is an oil filled fan hub on my 1926, and my 1924 too, so it has applicability to more than just the improved Fords, but not all model T's.

[TXGOAT2]

I believe that oil is best for bushings that run at higher speeds. Ideally, a bushing will have some kind of oil reservoir to assure a continouous supply.

[Petrah Phyre]

My hub has a "t-handled" plug in the fill hole with a spring loaded ball for adding lube without removal. I put grease back in because it was what I took out. Though this could just be oil drying out after 20+ years of sitting. I will go with changing out to a heavy weight oil if that's the way Henry wanted it.

[Mark Gregush]

Harry, this was never an "all model T's" discussion. Original post is in regards to the 26-27 fan. There is an oil filled fan hub on my 1926, and my 1924 too, so it has applicability to more than just the improved Fords, but not all model T's.

Larry brings up the early style using grease because that is part of the discussion about what lube to use RE people using grease instead of oil in the later style fan hubs.

[Humblej]

Sean, that T shaped ballbearing plug is an early grease gun fitting. Unscrew that and replace it with a oil fill plug available from the usual vendors.

[Petrah Phyre]

Thanks Jeff, will do.

[Humblej]

Sean, one more thing. There should be a paper gasket between the fan hub and the fan blade, that needs to be an oil leak proof connection. If you or a previous owner ever took the fan blades off that gasket needs to be replaced and I recommend using non hardening #2 gasket sealer there too.

[Petrah Phyre]

There was not a gasket, so I made one. I will order a manufactured one when I order the plug. So many things to do after a 20+ year rest. No compression on a couple of cylinders and looking through the plug holes, it still has the two piece valves. As you know...this will get costly as I keep digging deeper.

[RajoRacer]

I compare MOST Model T's to that of an ordinary (yea, right) plumbing job - might as well do it all or you'll have a leak farther down the line !!!

[jiminbartow]

Yes the felt is necessary to keep dust out and oil in. Grease is not what Ford intended the new 1926 - ‘27 fan to be lubricated with. There is an oil reservoir just behind the fan with a flanged shaft with a hole through the center that directs the oil from the oil reservoir to the pressed in front and rear bushings inside of the housing. If you use grease it will block the shaft inlet hole in the flange inside the reservoir and not allow the oil through the shaft, depriving the two bushings of lubrication. Occasionally check and keep the reservoir filled with oil. Jim Patrick

[TXGOAT2]

I suspect that the oil reservoir is not intended to be filled to the top. I would think that using an oil can to add some oil to the reservoir, then turning the hub to position the fill hole just slightly below the axis centerline and allowing any excess oil to drain into a small container would give the best results. That should allow oil to be available to the bushing when the engine is running, yet not leak out when the engine is stopped. A 10W 30 oil might work best here, since it could flow when cold. Removing the fan belt during the filling procedure would prevent oiling it and would permit checking the bushing for wear. My fan hub has a brass plug in it with an allen wrench socket.

[jiminbartow]

I have always filled mine to the top as much as it will hold. As the shaft turns, if there is any space inside the space between the bushings, the hole inside the center of the shaft, that transports oil between the center shaft oil tube and the bushing space pulls the oil into the space through centrifugal force, thus pulling more oil into the shaft, until there is no more room in the space between the bushings. Jim Patrick

[TXGOAT2]

If it doesn't leak to the point of being a nuisance, that's fine. When the engine is running at speed, the fan tends to move forward on the shaft, which would encourage oil to escape from the space between the bushings back into the reservoir. The hole drilled in the shaft would allow oil to return to the space between the bushings. At low engine speeds, the fan usually tends to move back and forth on the shaft slightly, which promotes oil distribution. A worn hub with significant foraward-backward slack would probably tend to leak excessively.

[halftracknut]

Ok, I will be the bad guy here sorry. Most of the T's I have found have a worn fan shaft and pulley and puke out whatever you lube you put in them..My case is this, I bought a new radiator from brass works and was running what I thought was a good fan setup after reading another post here I checked it out again a no lube and worn shaft and pulley ....so with a new $800 radiator rather than run the risk of major failure I bought a new set up with a sealed bearing and new pulley...also drilled the new shaft and put a cotter key in it....now I sleep good at night.....Merry Christmas....

[TXGOAT2]

I think the sealed hub is the best solution for a car that is driven a lot and for cars that are run at higher speeds. Given the cost of radiators, any hub ought to be checked frequently for indications of wear or lack of lube. The fan itself needs to be in good condition, with all blades at the same pitch, running in the same plane, and in good balance.

[jiminbartow]

I rebuilt mine. New shaft and new pressed in bushings.

[Jevil]

Hi.

Bringing this thread back up again because right now I am trying to reassemble my early '26 fan hub (the one with the clamping bolt on the underside, short version).
I changed the fan blades and seal, cleaned everything up and try to get it back together like in the sketch above with felt seal and dustcap.
But something does not work. Whenever I tighten the nut the shaft does not move anymore in its bushings. The dustcap with the felt seal is pressed against the eccentric and the rear bushing.
The eccentric's hole (where the shaft goes through) looks like that there maybe has been a thread in it - but my shaft runs straight through without screwing.

Should there be a thread for the shaft in the eccentric? This would explain the problem. With a thread the shaft could be screwed into the eccentric until correct belt alignment and the locked with the nut.
Does anybody have picture of correct assembly?

Best regards and thanks in advance,

Jens

[speedytinc]

The eccentric is not threaded for the fan shaft.
The drawing above is correct.
Note that the fan shaft sticks out further than the pulley end bushing. That provides the space for the felt washer.
The felt retaining washer fits tight to the eccentric & fan shaft, locking the shaft.
The bushings could be to thick in the flange or the fan shaft is not correct.

[Jevil]

Strange.
Found an assembly picture here: https://mtfca.com/phpBB3/download/file. ... &mode=view
But for me it's same problem.
If I tighten the nut (3986) hard enough that it doesn't come off I press 3987+3982+3983 against 3974B.
In the end it can't turn anymore. What's the trick here?

[jab35]

Sean: Are both bushings fully seated in the pully? (Bushing flange undersides tight against both ends of pulley) If so, you need to remove some flange material from one or both hub bushings. Part number 3974B in this assembly drawing:

app.php/gallery/image/1124

Does the fan axle support, p/n 3988 fit squarely against the 'step' in the fan axle? If the hole is wallowed out the shaft may be drawn into the washer and that may also cause the symptoms you describe. All the best, jb

[Jevil]

Even more weird: In all those 26/27-images the shaft is declared as 3966B, but in the shops the shaft with the recession for the wrench at the end is 3966C.
The early 26 does not have that support plate. There the dustcap seems to fit against the 'step'. But as it seems for me there's not enough space for the felt washer between bushing and dustcap. It is squeezed way to much. Maybe I will try a washer to make the thicker part of the shaft a bit longer.

[Allan]

Check that the front bushing is not binding on the radius between the bolt shaft and head. You may need to chamfer the bushing hole somewhat.

Allan from down under.

[DanTreace]

Here is the instruction of the 1st style or early '26 fan with the worm like drive eccentric using a special bolt from the Service Bulletins to help.

Have only experience with the later '26 fan and easy wrench adj. smooth eccentric.

1926FanAssemblyEarly-1-A.jpg (86.24 KiB) Viewed 60 times