Fan Belt Won’t Fit

[CatGuy]

My ‘26 Roadster came with a water pump. It also has a rough and falling apart belt that is 1-1/8x36. We figured out how to adjust the fan assembly to get the old one off, but the new one is just a bit too small. Anyone else have this? What is the first, second, last pulley to put the belt on?

[Scott_Conger]

If it doesn't fit, it doesn't fit. There is no further adjustment except at the fan. Order another longer one and ask the supplier if they will take the other one back unless it's marked up.

[DanTreace]

To adjust, loosen the eccentric by slightly loosening the lock nut and with a wrench holding the fan shaft flats, then rotate to eccentric, using the lug, to drop the upper pulley down.

Slip the new belt over the fan, then fit the new belt to the crank pulley first, you have to remove the ratchet on the crank handle to fit a new belt, very hard to snake it past that ratchet.

Next, fit the new belt over the water pump pulley, with the new belt now loose over the fan pulley.

Finally, adjust the fan pulley eccentric to pull the belt snug, not too tight. You should be able to pull the belt over the pulleys with about a 2-3 lbs. pull holding the belt between thumb and fingers.

IMG_3820 (500x375).jpg (86.92 KiB) Viewed 4855 times

[CatGuy]

To adjust, loosen the eccentric by slightly loosening the lock nut and with a wrench holding the fan shaft flats, then rotate to eccentric, using the lug, to drop the upper pulley down.

Slip the new belt over the fan, then fit the new belt to the crank pulley first, you have to remove the ratchet on the crank handle to fit a new belt, very hard to snake it past that ratchet.

Next, fit the new belt over the water pump pulley, with the new belt now loose over the fan pulley.

Finally, adjust the fan pulley eccentric to pull the belt snug, not too tight. You should be able to pull the belt over the pulleys with about a 2-3 lbs. pull holding the belt between thumb and fingers.
Mine doesn’t have that set up.


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IMG_3820 (500x375).jpg

[MichaelPawelek]

I used to be able to snake a belt in the ratchet to pulley gap but my arthritis no longer makes it possible so to easily remove the ratchet off of the hand crank I have removed the small bolt and nut and replaced them with this handy accessory clip on all my Model T’s.

[Ron Patterson]

Be aware 1926 Model T's had two different types of fan belt adjustment eccentrics.
Make sure you know which type you have before you start wrenching?

[CatGuy]

We measured around the pulleys and it came to 36-1/2”. Do they make belts that big?

[Moxie26]

Loosen the fan pulley eccentric and turn to measure for a lesser diameter fan belt for your application, leaving room at that eccentric to compensate for fan belt stretch and wear in use.

[Oldav8tor]

Do you have a photo of the original fan belt installed or a routing diagram? That sounds awfully long to me.

[CatGuy]

[CatGuy]

That didn’t work….

[Scott_Conger]

Lang's offers a 36" belt
it sounds like there is perhaps an exceptionally large pulley on the water pump. You may find that you can either make the Lang's belt fit, or change the pulley to a slightly smaller one. This will increase the pump speed which may or may not help cooling (if you even need the pump...my experience is that at least 1/2 of all pumps can be safely removed and cooling remains the same...and 1/2 will overheat and really do need the pumps...an entirely different thread for a different time perhaps)

[John kuehn]

Use a cloth tape measure such as one that’s used for clothing or a dressmaker and measure around the pulleys to get the length. You might could use a string also. This way there is no guessing and you can the correct length pretty close. Right now your guessing.

[CatGuy]

The belt I bought came from Lang’s. I can try to post other pictures tomorrow. Does anyone have pictures and measurements of the water pump pulley? The belt that came off is 1-1/8x36 and maybe 1/4” longer when stretched out beside the other. Also, I did measure with a dressmaker cloth tape.

[Norman Kling]

The water pump is not a Ford part. The belt originally went from the crankshaft pulley to the fan pulley, so the water pump is after market equipment. You need to order a belt just a bit longer than the one you have or perhaps Langs has a listing for a 26-27 with water pump. It would probably take the longest belt they have. There are also flat belts available at the local auto parts stores, which might fit even if they don't look exactly like the Ford belts.
Norm

[TRDxB2]

The belt I bought came from Lang’s. I can try to post other pictures tomorrow. Does anyone have pictures and measurements of the water pump pulley? The belt that came off is 1-1/8x36 and maybe 1/4” longer when stretched out beside the other. Also, I did measure with a dressmaker cloth tape.

Found a picture but no measurements. Would help to se pictures of your pump and he pulleys on the engine someone may have that combination

[DHort]

Cut the old belt and measure it. See how far it has stretched. Is it still 36 inches or 36+ inches?

[Eric Sole]

If you turn the excentric clockwise, viewed from engine side, the belt moves slightly away from the timer and it's wires. This gives a little more margin for wire movement as spark is adjusted.

[Mark Gregush]

Ran into same problem with friends 1926 with water pump. Didn't want to go one of the modern flat belts so I made one.

[Alan Long]

After reading all of the chat about changing a Fan Belt I’m adding it to my the list of
“Reasons why not to have a water pump” (it’s a long list!)
Alan In Western Australia

[DanTreace]

The belt I bought came from Lang’s. I can try to post other pictures tomorrow. Does anyone have pictures and measurements of the water pump pulley? The belt that came off is 1-1/8x36 and maybe 1/4” longer when stretched out beside the other. Also, I did measure with a dressmaker cloth tape.

One last thing to try to adjust is that water pump, sometimes the small bolt that tensions the water pump away from the block can also push the pump shaft and pulley outboard.

The bolt has a hex lock nut, loosen and see if you can pull the pump slightly back toward the block, to shorten the pump pulley distance from the fan pulley enough to fit the new belt.

[CatGuy]

Here's some pictures that I couldn't post this weekend. The water pump pulley is 7-1/4" in diameter.

[Mark Nunn]

Your fan pulley adjuster bolt is missing. See Rom Patterson's post for the bolt location. It is unlikely that you will be successful without the adjuster. It has a worm gear on it to turn the eccentric. I may still have an extra bolt if you need one but I replaced it due to wear. The good news is that your fan pulley mount is not broken, which is common.

[speedytinc]

Your fan pulley adjuster bolt is missing. See Rom Patterson's post for the bolt location. It is unlikely that you will be successful without the adjuster. It has a worm gear on it to turn the eccentric. I may still have an extra bolt if you need one but I replaced it due to wear. The good news is that your fan pulley mount is not broken, which is common.

IF it still has the correct gear cut eccentric & if the teeth are in tact where they contact the bolt.
AS is, there is nothing to lock the eccentric to maintain belt tension.

[CatGuy]

Your fan pulley adjuster bolt is missing. See Rom Patterson's post for the bolt location. It is unlikely that you will be successful without the adjuster. It has a worm gear on it to turn the eccentric. I may still have an extra bolt if you need one but I replaced it due to wear. The good news is that your fan pulley mount is not broken, which is common.

Oh, you mean the larger bolt that runs horizontal? Yes, I have that. It's just not in the picture.

[TRDxB2]

You have an early 1926 Water Outlet. The long bolt is used to rotate the concentric hub (like a worm gear). Later 1926 concentric hubs were smooth. You need to be careful in tightening the long bolt as making it to tight might cause one of the jaws of the water outlet to break.

cconcentric.png (245.99 KiB) Viewed 4528 times

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The fan shaft bolt holding the fan pulley also should look like this ( green box)

[CatGuy]

The plot thickens..... When I got this the shaft bolt doesn't go all the way through like yours. The belt was still snug. I suppose this will require removing the radiator?

[Mark Gregush]

You would just take off the water outlet and upper hose, you don't have to remove the radiator.

[Norman Kling]

From looking at your pictures, there is one thing which might help. First put the fan pulley back in place and adjust to the lowest and closest to the left of the car. Then install the belt to the fan pulley and water pump pulley. If you have the original crankshaft pulley without the lip, you might be able to slip it over that pulley.
Norm

[CatGuy]

From looking at your pictures, there is one thing which might help. First put the fan pulley back in place and adjust to the lowest and closest to the left of the car. Then install the belt to the fan pulley and water pump pulley. If you have the original crankshaft pulley without the lip, you might be able to slip it over that pulley.
Norm

You're saying that the shaft fan bolt should be towards the left rather than the middle like mine is?

[CatGuy]

So, I think I'm figuring this out.....maybe. We spent a lot of time turning the nut that goes on the fan shaft thinking that is how the tension is adjusted. Apparently that's not it? I'm starting to think that the function of that is to lock the tension. True? Then the lower, horizontal, bigger bolt is actually what adjusts the tension?

[TRDxB2]

So, I think I'm figuring this out.....maybe. We spent a lot of time turning the nut that goes on the fan shaft thinking that is how the tension is adjusted. Apparently that's not it? I'm starting to think that the function of that is to lock the tension. True? Then the lower, horizontal, bigger bolt is actually what adjusts the tension?

Correct! The nut on the fan shaft is just to hold the that pulley onto the concentric hub. The long bolt is to set the tension

[Eric Sole]

If you turn the excentric clockwise, viewed from engine side, the belt moves slightly away from the timer and it's wires. This gives a little more margin for wire movement as spark is adjusted.

I didn't realize that you had an early 26 water outlet when I wrote my comment. The threaded adjuster on that type automatically takes into account which way is best to rotate the excentric!

[CatGuy]

If you turn the excentric clockwise, viewed from engine side, the belt moves slightly away from the timer and it's wires. This gives a little more margin for wire movement as spark is adjusted.

I didn't realize that you had an early 26 water outlet when I wrote my comment. The threaded adjuster on that type automatically takes into account which way is best to rotate the excentric!

I didn't know, either. The car is legally registered as a '26, the frame is a '27 and the engine is a '28. That is, from what the numbers tell me......

[Dennis_Brown]

If you cannot find the correct belt, go to your local NApa store and see if they have a serpentine belt that matches width and length. Put it on with the smooth side against the pulleys, they are designed to run with pressure against the smooth side.

[CatGuy]

I got it on. It took a brake tool to pry it on over the pulley, sort of like putting a tire on a bike rim. It feels tighter than I think it should be, but I can still turn the fan without the belt moving.

[YellowTRacer]

No one is going my direction, not too unusual though. 2 cures. Make your own belt from an old leather waist belt (holds up your pants!) using 3 strands of bailing wire to hold it together. That process got me from Kansas to Missouri and back to California and a few more years of regular driving many years ago when my fan belt disintegrated on one of our trips. The other process is to buy the largest diameter belt that's available, in advance and grab your model T jack and lay the jack down on a table. drop the belt over it and jack it out so that the top and bottom of the jack is starting to stretch the belt. Every couple of day's or so pull the handle down for more pressure and eventually the belt will expand large enough to fit. Don't forget, that fan only has bushings and if the belt is too tight, they wont last. The belt only has to be tight enough to turn that water pump pully and no tighter.

Ed akla #4