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Broken fan shaft bolt destroyed my radiator
Posted: Sun Aug 30, 2020 8:01 am
by joe.wal
Disaster struck my 1916 T yesterday.
I wanted to locate a small leak at the radiator outlet to the lower hose and had the T running in front of the garage and playing a bit around by moving ahead and back in the driveway.
Then a loud chirp followed by a crashing sound occured.
As this was while backing up my feet - in a panic - did what they are used to do during 40 years of driving: hitting the middle pedal to brake ...

and of course we backed up more into the garage.
Still in panic mode my feet did the second reflex and hit the left paddle to press the clutch - and ahead it went ...
At least I came back to my mind and could stop and switch off the engine - luckily nothing was hit in the front and back.
After silencing the engine there was the sound of splattering water.
First thought was that the fan bracket went loose again as it did some years ago when I did not fasten it tight enough after changing the belt.
At that time only some fins were bent and it was not a big issue to straighten and repaint those.
Yesterday after opening the hood I saw the fan bent forward and stuck in the radiator.
The fan shaft bolt has broken (the whole construction not original 1916 but obviously an aftermarket style for 1920ff) and the fan destroyed some cores of the (also obviously aftermarket) radiator.
Now I know also what was the chirping sound I heard since some hundred miles - as the fan could always be turned by hand without too much effort I would never have suspected a problem in the fan hub cartridge - well now it is too late and I have a real problem.
Next week I will use my vacation (which was also meant to give the T some more miles this year) to take the radiator off the car and bring it to a radiator shop to see if they can repair the few cores that have been hit.
I still hope to pay only $$$ for a repair instead of $$$$$$$$$$$$$ for a new radiator (when freight to Germany , customs and taxes will add to a horrendous sum).
Maybe the vendor of my T here in Germany will have a radiator at hand to sell - I will contact him next week also.
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Aug 30, 2020 8:25 am
by Jerry VanOoteghem
While it's ugly, it should not be that hard to repair the leak.
It looks as if the bolt was cracked for a while, then finally "let go".
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Aug 30, 2020 8:50 am
by Bill Anziani
I had that happen to me as I was about to take the car for a ride. She started right up, then I heard this horrible noise, sounding like metal scraping against each other. Stopped the engine and took a look. The fan was lying up against the radiator, the bolt had broken where the threads meet the smooth part of the shaft. Thankfully, this happened right in the garage, and not while driving around.
It did not cut into the core, but made substantial damage to the fins
Took it up to a few radiator shops, and the cost of repairing was around $100 less than purchasing a new radiator
I purchased a new one instead of waiting for the repairs
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Aug 30, 2020 9:47 am
by Dan Hatch
What happened is the fan shaft broke after the fan hit the radiator.
Look at your bolt holding the fan bracket to engine. Looks like no split pin the stop it from rotating.
This is most important to install. Cost a friend a 15 brass radiator.
Everyone needs to check this on their car. Dan
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Aug 30, 2020 10:25 am
by RajoRacer
The "fan" bolt doesn't appear to be of an original design as the correct grease cup is the retainer for the through bolt - something looks odd about your set-up.
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Aug 30, 2020 10:27 am
by RajoRacer
I re-read your statement and you did elude to the fact it wasn't an original design - my apologies for the interjection !
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Aug 30, 2020 10:53 am
by RustyFords
Yikes. What a mess.
I think Lang’s has some of those fan shaft bolts available in NOS. At least that’s what I remember from ordering mine a few years ago.
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Aug 30, 2020 11:16 am
by Pep C Strebeck
Dan Hatch wrote: ↑Sun Aug 30, 2020 9:47 am
Look at your bolt holding the fan bracket to engine. Looks like no split pin the stop it from rotating.
Not just no cotter pin, no nut either. In the third photo there are 2 lockwashers between the fan arm and the timing gear cover, the bolt is too "short" in that configuration for a nut and cotter pin.
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Aug 30, 2020 11:34 am
by RajoRacer
Early fan arms did not use a nut - just a cotter pin.
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Aug 30, 2020 11:39 am
by Susanne
Let us know how it goes at the radiator shop... I was going to have a local shop do ours but decided against it as they may be good at modern stuff, but not so much on older stuff....
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Aug 30, 2020 11:42 am
by Dan Hatch
I maybe mistaken, but I think none of that type used a nut. Need to check service bulletins and or Ford service manuals.
That was so when adjusting belt you would loosen the bolt a little, adjust belt, then tighten bolt back without having to remove the pin or a nut. Dan
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Aug 30, 2020 12:55 pm
by jab35
This drawing of a 1911 fan assembly appears to show the same fan, hub and shaft as the one in your pic. The nut or the female grease cup fitting served as a locknut to secure the shaft. The support bracket and belt tightening arrangement on you 16 is obviously different, the failed part and method of securing to bracket appears to me to be identical to the drawing. Good luck with repairs, stay safe, jb
app.php/gallery/image/1211
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Aug 30, 2020 4:36 pm
by John kuehn
The radiator looks like it won’t take a lot to repair. The fins can be straightened easily enough. Looks like the damaged tubes can be pinched off, soldered and it will be OK. The bolt didn’t go all the way through the core and that’s a good thing. The repair won’t show from the outside.
Re: Broken fan shaft bolt destroyed my radiator
Posted: Mon Aug 31, 2020 6:09 am
by joe.wal
Thank you so far for all the sympathies and hints.
Earliest on Thursday I will have a chance to get back to work on the T and will post any progress then later.
I also do not mind about the fins and am still hoping that really only blocking / soldering the cores will do the job.
What I do not fully understand are the remarks about a missing cotter pin / bolt.
Where exactly should that be ?
Referring to the fan assembly drawing posted by jb I can say that the fan arm is still tight and did not move - my picture might give the impression from the angle I took the photo but this part was not involved (and I bought the T 5 years ago with this setting).
Rgds Joerg
Re: Broken fan shaft bolt destroyed my radiator
Posted: Mon Aug 31, 2020 6:49 am
by Dan Hatch
You need to remove the lock washers that are there. They do not belong there.
Read Par 127 in Ford Service manual. It tells how to assemble and adjust fan to engine.
Dan
Re: Broken fan shaft bolt destroyed my radiator
Posted: Mon Aug 31, 2020 1:14 pm
by jab35
My guess is those lock washers were used to move the fan closer to the radiator and/or to improve fan belt tracking. jb
Re: Broken fan shaft bolt destroyed my radiator
Posted: Mon Aug 31, 2020 7:43 pm
by Wayne Sheldon
That looks fairly close to the correct fan setup for a 1916. The major difference is that the '15 and I think most '16s had a brass fan hub
The 1917 through '19 hub is nearly the same except that it is made mostly of steel. Your fan is correct for a '17, and a perfect fit for a '16 and earlier (to 1910). The hub bolt, I can't see enough of it to tell if it was a right one or not. It does appear to have been cracked for some time.
The radiator damage is not serious. Any good radiator shop or hobbyist with soldering expertise and tools should be able to fix it in about an hour.
So, I am basically repeating what others have said.
Re: Broken fan shaft bolt destroyed my radiator
Posted: Mon Aug 31, 2020 8:28 pm
by Allan
I agree with James. The washers between the front cover and the fan arm are likely to have been installed to get the fan belt tracking correctly. That has meant that the cotter pin hole has been occluded, not a good situation.
The fan, arm and shaft look about right for a 1916 model. Refitting it requires that the arm be twisted/bent so that the fan shaft is parallel with the crankshaft to solve the belt tracking problem. That will allow the fan arm mounting bolt to accept a cotter pin. A new fan shaft should be fitted and bolted up tight against its shoulder. If this jams the fan, the bushing faces need to be worked on to free it up. Then the locknut becomes a real locknut, not just a locator for a shaft not fitted all the way in. That shaft should be tight against its shoulder and the arm. In the original set-up with the female thread greaser, that greaser is the locknut. As such, it is not capable of locking the shaft tight if the shoulder on the shaft is not engaged.
Hope this helps.
Allan from down under.
Update: Broken fan shaft bolt destroyed my radiator
Posted: Fri Sep 04, 2020 6:07 am
by joe.wal
Yesterday I took the radiator off and delivered it to the radiator shop.
They detected that the radiator has seen some repair already in the past (obviously the core was soldered where it meets the upper tank).
Estimated time for the repair by them is abt. 4 hours but they took the order only as a 'trial repair without guarantee'.
Well, in about two weeks I will see the result.
Removing the nut on the drivers side nearly took one hour as the plate holding the bolt within the frame was turning and gave no resistance. Now I know why the replacements are longer ... At least after some fails I found the trick and tool to block it while loosening the top screw.
I also now saw what you meant with the missing cotter pin at the bottom of the fan bracket - thanks again for the hint.
Next thing now is ordering the new fan shaft.
Looking at my fan hub cartridge I noticed that I cannot turn the inside bushings - is that correct or is it supposed to turn freely when i hold the cartridge tight ? Do I also need a new one because some bearing is locked ? Or is the whole fan pulley meant to turn on the shaft ?
The number on my assembly (I read it as 16031) is also something that does not match to available parts e.g. at Lang's.
Is it Model T at all ?
Re: Broken fan shaft bolt destroyed my radiator
Posted: Fri Sep 04, 2020 8:21 am
by Jerry VanOoteghem
The whole pulley, along with the bushings pressed into it, are supposed to spin on the shaft.
Re: Broken fan shaft bolt destroyed my radiator
Posted: Fri Sep 04, 2020 10:01 am
by Dan Hatch
Does fan have the old bushing or the new bearing modification?
Re: Broken fan shaft bolt destroyed my radiator
Posted: Fri Sep 04, 2020 10:02 am
by Jerry VanOoteghem
Dan Hatch wrote: ↑Fri Sep 04, 2020 10:01 am
Does fan have the old bushing or the new bearing modification?
That's an important question to answer and could change my advice above!
Re: Broken fan shaft bolt destroyed my radiator
Posted: Fri Sep 04, 2020 2:22 pm
by TRDxB2
The bearing pulley is for 1921-1927 he said his is a 1916 and the picture isn't of a bearing pulley. But the picture of the broken shaft appears to be drilled out - was that done for an oiler? Is it the correct shaft?
Re: Broken fan shaft bolt destroyed my radiator
Posted: Fri Sep 04, 2020 9:44 pm
by Allan
Frank, the early fans had no plugged oiler hole at the front of the pulley. They are lubricated by a greaser from behind. The shaft is drilled at the threaded end to allow passage of grease from the greaser into the centre of the shaft. That greaser has the same cap as others on a T, but the screw in part has a female fine thread to allow it to screw onto the fan shaft. It becomes the locknut, BUT, as it is just pressed metal, it is rather thin and will not take a lot of tension. For this reason, the shaft has to be fitted up tight to the shoulder. Then the greaser has its best chance of locking the shaft.
Too often, fans are assembled by winding the shafts into the arms until there is load on the fan, and then backed off a little. This means the shaft has not been tightened up against its shoulder to the arm, and then the locknut is tightened and expected to hold the shaft in that position. WRONG!
If the fan binds before the shaft is tensioned up to the shoulder, the bushing faces need to be worked on to free the fan. Once the fan can be tightened against the shoulder, and it runs freely, then the locknut becomes just a locknut. This applies even with modern ball bearing replacements.
Allan from down under.
Re: Broken fan shaft bolt destroyed my radiator
Posted: Fri Sep 04, 2020 10:42 pm
by jab35
Frank: Take a look at the Vowellart Image link in my Aug 30 post above.
Over tightening the fan belt might have contributed to the failure shown in the original post. The modern rubber belts do not stretch as easily as the original leather belts, and if over tightened they do not relax/stretch like leather so the (over)load persists and the bolt eventually suffers a fatigue failure. The hollow bolt further increases susceptibility of the shaft to fatigue failure at the mounting arm, compared to the later solid shaft design where oil was introduced through the fan hub. Academic at this point, I know, hope the radiator is repairable.
jb
Re: Broken fan shaft bolt destroyed my radiator
Posted: Fri Sep 11, 2020 11:57 am
by joe.wal
Small update again: took out the the front bushing and it is extremely worn. So I believe the problem was existing some years already (as some of you supposed correctly). Strange that I did never see traces of brass below the fan - probably blown away by the rotating crankshaft pulley.
tension of the belt was not too tight - it took not too much force to turn the fan by hand (engine not running of course

) and I installed it after buying the car - since then only 700 miles of driving.
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Sep 13, 2020 6:34 am
by joe.wal
... and regarding the fan adjustment bracket found this on the 'Rip van Winkle" 1916 Tourer: shims and no cotter pin

- DSC_0367-1 part.jpg (45.15 KiB) Viewed 12030 times
credits to
www.dragoneclassic.com/the-rip-van-wink ... el-t-ford/
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Sep 13, 2020 7:12 am
by Kerry
Well in reading that I would say maybe a rip-van-winkle but not "The Rip-van-Winkle", shows signs of some things well used and some replacements over the last 100+ years. 100% original is a little off.
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Sep 13, 2020 7:19 am
by joe.wal
Well after reading now the topic posted recently the real Rip van Winkle seems to be a 1917 - so just pretend that I never wrote the above ...

Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Sep 13, 2020 10:26 am
by DanTreace
Here's a photo of early 1917 with the shroud used to increase air flow, only used a few months, Ford idea didn't work as the radiator didn't cool well without air passing under the top tank that is full of the return hot coolant.
Any way a good shot of the iron rivet pulley and the grease retaining shaft, with its cup, the cup is threaded onto the retaining shaft, to lock the fan pulley in place. Doesn't show the fan arm mount and its bolt, but that bolt is threaded into the front plate, and has a hole to place a large cotter jammed with one leg against the front plate to keep that large bolt from backing out and letting the fan rattle or move forward to the radiator core
Later version fan that uses heavy oil placed inside the alum pulley housing, the zerk is incorrect as should be a plug for the oil , but shows the large cotter holding the fan mount bolt from backing out.

- Igh0706.jpg (125.08 KiB) Viewed 11981 times
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Sep 13, 2020 7:59 pm
by Allan
That is an interesting top outlet on that 1917 radiator. I have never seen anything like it. If it is brass, the later tinned steel offering was a step backwards.
Allan from down under.
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Sep 20, 2020 7:32 am
by joe.wal
So after a soldering job for abt. $ 70,- my radiator is back.
Now I am to order new parts for the fan shaft.
With yours and the help from Steven of Lang's I do know now what to order.
Alternatively I am thinking about experimenting with a plastic fan (which would do less harm in case of any failure of the 'system').
I am still waiting for an anwer of Steve for that below - anyone of you has this part available and can post the dimensions please ?
Then I would try to find out whether a part like this would fit to that cartridge:

- Mercedes.jpg (12.96 KiB) Viewed 11848 times

- Opel.jpg (28.64 KiB) Viewed 11848 times
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Sep 20, 2020 8:11 am
by Jonah D'Avella
Joe, I have an extra fan pulley assembly, probably original.
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Sep 20, 2020 8:36 am
by Jonah D'Avella
Here is a picture.
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Sep 20, 2020 8:07 pm
by Allan
Jeorge, why do you want to change from that which you have? All the parts you need are available. They work well. They look correct rather than out of place. This particular wheel does not require reinventing.
Allan from down under.
Re: Broken fan shaft bolt destroyed my radiator
Posted: Tue Sep 22, 2020 6:57 am
by joe.wal
@ Jonah: thanks a lot but I am afraid the freight rate to Germany might be on the high side for that experiment
@ Allan: you are right, I will reinstall the existing assembly but am just looking for an alternative to not hear again that horrible sound of a steel fan crashing into the Radiator ...
Meanwhile Steven Lang also sent me the dimension I asked for (2.15" distance between bolt holes)
Re: Broken fan shaft bolt destroyed my radiator
Posted: Tue Sep 22, 2020 8:11 am
by Kaiser
Joerg, a plastic fan whirling around at speed will do the same harm to a radiator. so keep the original

Update Oct 31st: Broken fan shaft bolt destroyed my radiator
Posted: Sat Oct 31, 2020 1:43 pm
by joe.wal
Finally I was able to proceed with the repair now (and I gave up on the idea of experimenting with a plastic fan).
Indeed it went not too well ...
After 4 weeks the package from Lang's arrived this week (3 days transit from the USA to Frankfurt and 3 weeks delay by the German customs).
Freight and custom fees just doubled the value of the parts I ordered.
Having unpacked I had to find out that the fan shaft bolt did not fit into the new bushings (neither did the old broken one) - 0,02 mm the bushings diameter was to small.
After several tries of filing and grinding and two hours later I had won the fight against the brass bushing and the shaft did fit.
Obviously the manufacturers of the bushings are no fans of correct measuring ...
At least I could start to install the new parts and got it together quickly.
What troubled my mind already since weeks was 'how can the thing work with the shaft and the lock nut (now the one with the greasing cup) being tightened ?'
And indeed the fan could not be turned by the belt after tightening everything.
My only idea was to untighten the fan shaft a bit and now the fan is turning.
I made a small video of how it is now - please be so kind to give me a feedback if the whole thing is supposed to be like that or if I must fear that the fan will get loose again after some miles of driving.
https://youtu.be/EaJZDlI7X_o
Next the radiator was reinstalled and filled with anti freeze mixture.
After the first 5 liters I heard the sound of dripping water.
Obviously the radiator repair caused some new leaks - this time on the lower outlet where it is soldered to the lower tank.
You see it on the upper right corner of the photo.
I hope to cure it with HYLOMAR which I applied and will try again next week to fill the radiator again.
Last project of the day was to try to remove the rear wheel on the drivers side.
Since I have my T (now for more than 5 years) there was a knocking sound while driving.
First I thought about loose spokes but never found one.
Also when the rear axle is lifted there is no sound when turning the wheel.
Some day I read about someone who detected some bolts holding the brake plate to be too long and rub against the wheel nuts.
So with my Lang's order came along the wheel puller.
After removing the axle nut, installing the puller and aprox. 50 hard blows from a big hammer nothing happened or moved.
I let it sit under pressure one night but today also no chance of getting the wheel off.
So I fastened the axle nut again and will try the driving method with the nut loosened one turn - if the T will drive sometime in the future again ...
Stay safe and healthy everyone !
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Nov 01, 2020 1:55 am
by Allan
Joerg, when the shaft is tightened and the fan will not turn, it means the bushing faces need to be machined down a little. The shaft is designed so that the step is to thread hard up against the arm. I effect, the arm is a nut. By backing off the shaft you have undone the 'nut' somewhat, and you are now relying on a pressed brass sleeve in the greaser to be the locknut to hold the shaft in place. I would not recommend this.
Allan from down under.
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Nov 01, 2020 4:15 am
by Wayne Sheldon
To add to what Allan B said, the bracket/arm that the fan shaft threads into should have on the front end of the threaded hole, NO threads for about 3 mm. The fan shaft/bolt should have a "no threads" shoulder that should turn (thread) into that no thread area. This is very important! The no thread shoulder into the no thread end of the hole is there to take the major stress of the fan and belt. If the fan is too tight to turn, it is the faces of the fan hub bushings that need to be cut back (dressed down, faced, ?) only enough to free up the fan. Whether the front face or the rear face should be trimmed might make a difference in how it centers the fan forward or back. Sometimes it matters, sometimes it doesn't.
That fitting of the fan is probably what caused your fan shaft to break before. Whoever put it together, instead of carefully fitting the bushings left the fan shaft/bolt too far forward, causing the threaded area of the fan shaft to take the downward pull of the fan belt. the threaded part of the shaft is a easy place for bolts and hollow shafts to begin a crack and break.
Alles gute, mein guter Freund.
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Nov 01, 2020 7:34 am
by joe.wal
O.K. - thank you and 'danke' so far.
So my fault might be that I did not replace the rear bushing (marked red in the drawing below) as it was much thicker than the old one (which ends flat with the fan hub) ?
I was afraid that the fan would be too near to the radiator but I might begin to understand.
The fan shaft is meant to be tightened to the bracket and the distance of the shaft wihout thread should be exactly the length of the inner fan hub
plus rear bushing ?
Sorry for sounding stupid but I am kind of blocked in my ability to imagine the construction ...
Perhaps it is like that (although drawing is for 1920-24) ?
Credits to MTFCA for the drawing (excerpt)
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Nov 01, 2020 10:08 am
by jab35
Joerg: My experience using original Ford 3966 shaft and 3962B hub with 2 modern replacement bronze bushings 3974B was the bushings (after reaming the bore) allowed just enough endplay for the 3983 felt oil seal, and once assembled there is no front to back movement of the fan on the axle. That felt should be lightly compressed in order to retain oil for the bushings. As for the modern hub with ball bearing, if the bearing is press fit in hub but slip fit on shaft bolt, then I assume a spacer(or spacers) is required to keep the fan positioned relative to the radiator and at the same time properly align the fan belt. Best to you, jb
CASE CLOSED: Broken fan shaft bolt destroyed my radiator
Posted: Sat Nov 07, 2020 11:57 am
by joe.wal
At least I understood how the whole assembly is meant to work and found out that the new fan shaft was 0,2 mm to short. For that reason it could not be fastened to the bracket without blocking the roller.
Today I somehow managed to take enough material away from the rear bushing and luckily I could fasten the shaft to the bracket and the roller still rolled - and that without too much space between roller and bracket.
After filling up the radiator with anti freeze mix I did a test run of the engine and it took several minutes until warm water began to move through the connection pipe to the cylinder head.
The radiator itself did not leak during the short test and only a faint 'gurgling' appeared after shutting off the engine.
Still there are some drips from the seam of the lower outlet so Hylomer did not do the trick (or I applied not enough) but this slight dripping does not worry me too much for the moment.
Thanks again for all the valuable hints !
Solved for now (?): Broken fan shaft bolt destroyed my radiator
Posted: Sat Apr 03, 2021 9:22 am
by joe.wal
Hello to all and wishing some peaceful and healthy Easter Holidays !

- FROHE OSTERN.jpg (51.79 KiB) Viewed 10117 times
This week I hopefully have solved the problem with my fan assembly finally.
As the fan got struck after some hundred meters on the test drive last year I now had to remove some material from the rear fan pulley bushing so that the fan shaft now has full contact to the fan bracket and the fan turns freely with the shaft tightened (see marking). Also added 'screw lock medium' to the threads of the fanshaft to secure it in the bracket and also to secure the screw of the grease cap.
During the test run in the garage for some minutes it did not work loose so I hope this will last now for a while.
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sat Apr 03, 2021 12:08 pm
by Dan McEachern
Just a suggestion- do not make the fan belt too tight- just tight enough to rotate the fan. also, with new fan bushings, after running for a few minutes, feel the fan hub to see if it is getting hot. If so, you need more clearance in the bushings.
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sat Apr 03, 2021 1:59 pm
by Burger in Spokane
When I got serious about T ownership, I began to hear talk about
water pumps and fans and Henry's thermosyphon design. I asked
questions, and as I did more work on my T and finally did a full
rebuild, I opted for the no water pump/no fan/new radiator option.
I love the lack of front end clutter/easy access of nothing being up
there, and after 3 years of driving, I have had exactly zero problems
keeping the engine cooled.
The reasons given for water pumps and fans being bad was that they
were not stock, and the result of being a bad idea "fix" for people too
cheap to buy a new radiator, with the end result being fan blades getting
tossed into the radiator. Well, most of this aside, I do not want a fan
pitched through my radiator, and not having a fan there in the first place
sure does reduce the chances of that happening, so I went that route.
Secondly, the successful use of Henry's thermosyphon theory has proven
itself very well on my rig.
New radiator, no fan, good cooling .... sounds like a winning plan to
this semi-greenhorn Model T fool. Rather than debate how to keep a
fan from doing damage, perhaps the question that needs to be asked is
"Why have a fan at all ?".
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sat Apr 03, 2021 7:41 pm
by TWrenn
Frohe Ostern to you Joerg!
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Apr 04, 2021 9:19 am
by joe.wal
Danke Tim !
@ Dan: yes, I was aware of the fan belt not putting stress on the hub - I installed it with not too much tension
@ Brent: at least with the damaged and soldered radiator after some minutes of test run in the garage it did not even gurgle after stopping the engine (and the top tank was hot enough I could not leave my hand on it). I envy you for your courage to drive without a fan - I just would have a bad feeling and I want to believe that the engine itself is cooled a little bit by the increased exchange of air that the fan blows.
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Apr 04, 2021 10:44 am
by TXGOAT2
The fan is only needed during situations where the car is standing still with the engine running for an extended time, such as during a traffic jam or parade or going through a slow drive-through line, and then only in warm weather where there is little or no breeze. An exception might be a TT truck, or a car running slowly on a sandy or muddy road, or a car being used for belt work, such as running cordwood saw, plowing, or driving slowly up Pike's Peak. A fan can reduce the effects of a clogged radiator, poor driver management of spark control, and dragging transmission bands. An ideal fan for a Model T would only function when needed. Belt driven fans are least effective when needed most, and consume considerable power at higher engine speeds, assuming the belt does not slip, which a flat belt on a T fan likely would. A water pump installation would probably increase the chances of the belt slipping on the fan pulley at higher RPM by reducing the amount of belt contact at the fan and crank pulleys.
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Apr 04, 2021 11:07 am
by FordFool
Why are those lock washers still on the fan arm bolt? They should be removed and a pin put thru the bolt. Two times I have seen the bolt with no pin back out and the fan destroy a brass radiator. Just my opinion. Don
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Apr 04, 2021 5:40 pm
by halftracknut
I bought a new pulley and bolt in jan. just to prevent the exact thing to my new $900 radiator on my 26....you have to dress the bolt just a bit to fit the bearings but worth the effort...Well foot in my mouth ...I just finished drilling a cotter pin hole in the new shaft....but I did have a lock washer and nut in place.....THANKS for this subject post......
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Apr 04, 2021 6:53 pm
by Colin Mavins
well it looks like I have some spring work to do before I take the T for a drive, Check the fan blades for cracks and check the fan bolt as all it gets is grease two times a season. I did find 5 complete fan assemblies as spares so I'm good for parts. Cheers Colin
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Apr 04, 2021 8:51 pm
by Allan
Randy, it is the fan arm bolt which goes to the timing cover which needs the cotter pin, to stop it backing out. On a brass radiator car the fan shaft does not have a cotter pin. Instead it has a greaser with a female thread which screws onto the end of the shaft as a locking nut. If your fan shaft has a nut and cotter pin, it is a later version, used when the fan is oiled through a plug in the front of the fan pulley.
Allan from down under.
Re: Broken fan shaft bolt destroyed my radiator
Posted: Mon Apr 05, 2021 3:00 am
by Allan
Joerg, you look to have it sorted, but the issue of the fan arm to timing cover bolt has still not been addressed. I see the wider than usual fan belt you are using, and note that some of its width must be riding off the back of the bottom pulley. This indicates that the fan shaft is down somewhat at the front. the arm needs bending up to correct this. If you then remove the spring washers between the bottom of the arm and the timing cover, before bending the arm to get the belt running correctly, you should be able to fit the cotter pin through the fan arm bolt at the timing cover. That bolt must be captive. The unforgiving nature of modern belts means any out of round/mis-alignment in either pulley will load/unload the arm, making it subject to loosening.
Allan from down under.
Re: Broken fan shaft bolt destroyed my radiator
Posted: Mon Apr 05, 2021 4:58 am
by Virtus
Jorge, I totally agree with Alan that the fan belt is no sitting comfortably as the pulleys appear to be out of alignment. This will probably lead to a premature failing of the belt, and, probably worse still, cause the fan hub to run hot. To check the alignment I would suggest that a straight edge is held against the bottom pulley to ascertain that the top pulley is in line and parallel to the top pulley.
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Jun 27, 2021 7:28 am
by joe.wal
At least the assembly did 'survive' some test runs until now so I assume this issue as finished for now.
Thank you again for all contributions !
Here we go:
https://youtu.be/m6dqPaCiCdw
Re: Broken fan shaft bolt destroyed my radiator
Posted: Sun Jun 27, 2021 11:55 am
by Original Smith
I will never use a reproduction fan shaft. I've got a good supply of originals for my use. I have a '13 with over 55,000 miles, and still has the original fan shaft, and threaded grease cup retainer. This is a critical area, and too many don't pay attention to what is correct for their cars.