Can't tighten fan belt on 27 Roadster

[Old Redneck]

The adjustment to tighten up the fan belt the center nut does not lock the fan belt. I have two 27 and the other waterneck has a bolt on the lower part to tighten to stop the belt comming loose. But the other waterneck does not have this? All it has is the center nut 11/16 to tighten up but that doesn't stop the belt from comming loose.How do I stop the center from turning comming loose? There no bolt on the bottom that tighten up that stop from turning. I hope you understand what I am trying to say. There must be several different water necks?

[Jack Innes]

The later type of fan bracket is adjusted by loostening the nut that holds the bearing & rotating the eccentric. The earlier one, pre Jan. 1926 had a worm screw & lock nut. It sounds like you have one of each.

[Old Redneck]

Correct the one that does not have the bolt and nut to tighten on the bottom How in the world do you tighten it uo so the belt does not come loose? I tries lock washers larg ones and small ones. I am lost on this. It got to be simple but?

[Doug Money]

There is a protrusion alongside the side of the nut. Loosen the nut and pry between the protrusion and nut to "twist the eccentric" that Jack mentioned. This tightens the fan belt. When the belt is adjusted, retighten the nut to hold the adjustment.

[tmodelman]

This is the later style of the two '26 Improved Car fans at the water outlet, note the bolt has two flats at the end, hold this threaded bolt firm, then loosen the lock nut. Then rotate the lug on the eccentric to loosen or tighten the fan belt. The threaded bolt that holds the pulley tight to the fan bracket is then locked in place with the lock nut.

[Old Redneck]

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I tighten as you say but the center is not tight.I tried lock washers with no luck?

[Old Redneck]

That the way in the picture mine is On the center shaft where the nut goes what beside the nut?

[Old Redneck]

I just put a large flat washer then the nut and tighten up the nut? Will see if that works. There got to be a better way.

[redmodelt]

Could be you have the wrong shaft.
http://www.modeltford.com/item/3966B.aspx
http://www.modeltford.com/item/3966C.aspx

[Doug Money]

Recheck my picture above to see what we are referencing.

[Old Redneck]

From looking at the picture above mine looks correct.But when I tighten the nut up the cylinder still turns and loosen the belt.

[Jack Innes]

Are you missing the correct washer as shown on the left in this picture? Is it right side out - there is a flange. Or are the threads too short on the shaft? - a spacer would fix that.

[Old Redneck]

What the washer look like you lost me there.

[tmodelman]

Here is a sketch of the late Improved Car fan assembly showing all the parts.

The center bolt (threads that stick out the backside) is the axle for the fan pulley. If that is loose (fan pulley wobbles, could be bolt is loose or fan bushing is worn). The fan axle bolt has a large flat end that is inside the fan hub, you have to take off the fan blade assembly to hold that bolt as you tighten the bolt with the flats, using a small wrench on the other end of the bolt after you loosen the lock nut.

Now to make the fan belt tight, you must rotate the cylinder in the bracket, that cylinder is an eccentric cam, it will move the whole assembly up or down as you rotate it, with the fan belt in place. Use the lug on that cylinder to move it. Sometimes rust is holding the cylinder, there is a small hole port to add oil. Or add penetrating oil, or you may have to remove the whole thing and fix what is wrong.

[Jack Innes]

Originally Posted by Redneck

What the washer look like you lost me there.

This special washer goes between the fan shaft & the front of the water outlet casting. The step in the fan shaft pushes on this piece & the nut pushes forward on the "cam" with the outlet casting in between.

There could be an accumulation of rust or dirt between the two preventing things from tightening up.

Have you had these parts all apart? As Tmodelman suggested, it would be wise to take it apart & clean everything up.

[yachtsmanbill]

While on this subject Im gonna add a tinkerin' tip... When the lug is at the 12 oclock position, the belt is at its' loosest. Bringing that lug down either side will move the eccentric into a tighter position which is fine, BUT, move it down on the passenger side to keep the belt from rubbing on the timer. Hmmm
When I did mine I found the eccentric and the washer alignment pin to be missing. If memory serves me correctly, I used a 1/4" spilt pin in the eccentric so that both pieces turn in unison.
Theres a double flat on the back end of the shaft as a hold back to loosen/tighten the main nut. If the correct shaft is used, the nut is loosened, the eccentric turned as needed, then re-tightened with the shaft pulling up against a shoulder. The wrong shaft will pull the assembly up tight and it wont let the fan turn.
Take that thing apart and clean it and lube it with some grease so that the cam spins freely in your hand. Make sure the starboard side oil hole is clear as well and ad a drop of oil when you oil the front end. Some people use a grease fitting under the fan, but Hank used a 1/8 npt screw plug which was removed and filled with oil. The fan always blew oil all over the inside of the hood... ws

[Old Redneck]

When I tightenthe nut the center turns and tighten the belt fine noe when I run the T down the road for a few miles the belt is loose again and the nut is also . I tighten up again and the same happens. Loose again.

[John Otis]

And also make sure you have the correct belt.

[redmodelt]

Maybe it's just plain worn out.