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How to remove cooling fan hub from engine.

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TR3MINI Avatar
TR3MINI Jim Sipos
Englewood, Ohio, USA   USA
I am trying to install an electric cooling fan and need to remove the cooling fan hub extension to make room for the new fan. But I cannot figure out exactly how the fan hub comes off. From looking at the cut-away drawings of the engine in the service manual it appears to me as though the hub and fan belt drive pulley are attached via a large bolt through to the crankshaft. If this is true how can you keep the engine from turning over while trying to loosen that bolt?

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CJD john durant
Southlake, Texas, USA   USA
That is how it is held. You can put the car in 4th and lock the handbrake, or use an impact wrench to remove the long bolt. Once the bolt is removed, the hub is normally a press fit on the crank, so a puller will be needed.



John
Southlake, TX

'55 TR2



Edited 1 time(s). Last edit at 2017-09-19 02:30 PM by CJD.

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TR3MINI Jim Sipos
Englewood, Ohio, USA   USA
Thanks loads! I should be able to do that. Just wasn't sure how it was fastened.

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Jacad Avatar
Jacad Gold Member Barry Shefner
Montreal, QC, Canada   CAN
1959 Triumph TR3A "Loose Wheels"
1976 Triumph TR6 "The Tweetster"
Jim,

You could also leave everything the way it is and add the fan on the other side of the radiator so that it pushes air rather than pulling it. If you do go the hub removal route, you will have to shorten the long crank bolt by approximately the length of the hub and add new threads.

BTW, you can also put a pipe wrench on the hub to stop the crank from turning so that you can loosen the bolt



Barry
59 TR3A 0TS57675LO - "Loose Wheels"
76 TR6 CF54266U - "The Tweetster"
Website: Triumph TR2-TR3-TR4 www.trtriumph.com/ (sorry for not keeping it current for the past couple of years)



Edited 2 time(s). Last edit at 2017-09-19 05:34 PM by Jacad.

mcoomey Avatar
mcoomey Silver Member Michael Coomey
Paxton, MA, USA   USA
Jim,

Here's my setup to pull the hub. Once I got the crank bolt removed I made up a threaded shaft with a dimple on the end to center the puller and it came off without any trouble.



Michael Coomey
Paxton, MA

'57 TR3


Attachments:
tr3_hub_pull_1.jpg    39.5 KB
tr3_hub_pull_1.jpg

tr3_hub_pull_2.jpg    43.2 KB
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TR3driver Randall Y
Confusion, Los Angeles, USA   USA
In reply to # 1486432 by Jacad If you do go the hub removal route, you will have to shorten the long crank bolt by approximately the length of the hub and add new threads.
Or you can buy a ready-made bolt. 5/8 NF IIRC

However, you also need a filler piece to go under the head of the bolt (either way), so the bolt clamps the remaining hub firmly. I tried using a big flat washer, which worked once, but on the second engine it pulled up against the end of the crank instead of the hub. Worked at first, but let the hub wiggle just enough to eventually make a mess. Someone sells a very nicely machined piece, but I can't remember the name offhand.

I'm afraid it doesn't show very well, but I made this one from a cast iron pipe cap.




Randall
56 TR3 TS13571L daily driver
71 Stag LE1473L awaiting engine rebuild
7? Stag awaiting gearbox rebuild

Jacad Avatar
Jacad Gold Member Barry Shefner
Montreal, QC, Canada   CAN
1959 Triumph TR3A "Loose Wheels"
1976 Triumph TR6 "The Tweetster"
This is likely the fan eliminator kit that Randall mentioned http://www.pattonmachine.com/Fan-Eliminator-Kit.htm



Barry
59 TR3A 0TS57675LO - "Loose Wheels"
76 TR6 CF54266U - "The Tweetster"
Website: Triumph TR2-TR3-TR4 www.trtriumph.com/ (sorry for not keeping it current for the past couple of years)

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TR3driver Randall Y
Confusion, Los Angeles, USA   USA
In reply to # 1486523 by Jacad This is likely the fan eliminator kit that Randall mentioned http://www.pattonmachine.com/Fan-Eliminator-Kit.htm

That's it. Thanks, Barry!



Randall
56 TR3 TS13571L daily driver
71 Stag LE1473L awaiting engine rebuild
7? Stag awaiting gearbox rebuild

TR3MINI Avatar
TR3MINI Jim Sipos
Englewood, Ohio, USA   USA
Thanks to all who replied. All replys were very helpful. You guys are great.

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TR3driver Randall Y
Confusion, Los Angeles, USA   USA
I should probably add a bit of TR lore here. The theory has been advanced that the original metal fan riding on it's rubber bushings acts as a harmonic vibration damper and reduces stress in the crankshaft. The crankshaft has several resonant frequencies (an old-timers test for a crack is to hang the shaft up and ring it like a bell), and operation at certain rpms can excite those frequencies until the extra stress is enough to work harden and start a crack.

Now I've never paid much credence to this theory, and I've covered hundreds of thousands of miles (with various engines and TR3s) without a damper or original fan. That is, up until a few months ago. I'd been noticing a faint noise kind of like a rod knock, but only at lower rpm and only when the engine wasn't fully warm. I assumed it was a sign I needed to replace the rod bearings, and kept driving (gently). But a few days later (still driving gently), the sound suddenly got much louder and the oil pressure took a sharp drop. Flat bed home, drop the oil pan, turns out the front crank web is broken! The break was hard to see at first, in fact the first thing I found was some strange damage around the #1 rod & crank journal. But when I pried the crank fore and aft a bit, I could see that dark line open up and most of the front web didn't move with the rest of the crank.

Life intervened and I don't have it out yet (so no photos). And of course I can't prove that the crack had anything to do with running without a fan. Maybe it's just coincidence, and my crank just happened to have a casting flaw that didn't show up for 50 years! I don't even know for certain that it is the original crank, I bought the car as a "barn find" about 10 years ago.

So, draw your own conclusions. But for sure, my new crank is going to have a damper on the end!



Randall
56 TR3 TS13571L daily driver
71 Stag LE1473L awaiting engine rebuild
7? Stag awaiting gearbox rebuild

CJD john durant
Southlake, Texas, USA   USA
To add, steel cranks (like our TR cranks) are much more prone to resonant frequencies compared to cast cranks. Rap a cast crank it it makes a dull thud, as the internal carbon and flaws act as internal dampers. Hit a steel crank and it will ring like a bell...showing it will maintain a resonant frequency much better, and that is not a good thing.

If you drag race exclusively, you pass through the resonant frequencies to fast for them to be a factor, so a damper is not needed.

Engines that cruise at the same RPM for long periods (basically the definition of a street motor) are much more likely to spend long periods at the crank's resonant frequency.

Aircraft operating manuals actually list RPM's which are NOT to be used for cruise, showing crank fatigue from resonance is both real and something to be respected.



John
Southlake, TX

'55 TR2

lejjr Avatar
lejjr Lysle Johnston
Eastport, Michigan, USA   USA
Use a breaker bar with the correct Hex Let the bar down to the floor (parallel to the radiator) and then hit the starter; bolt will be undone instantly.

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