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Discussion Topic:
Blades breaking off two fans
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40headaches |
05-08-2016 @ 3:36 PM
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Member
Posts: 36
Joined: Oct 2015
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I have fan blades breaking off my radiator fans. Two seperate times. Less than 50 miles driven between repairs of the first time. Both blades were in good condition. Both times they broke off coming from 1st to second gear. I need some big time help in figuring this out. Motor is a 1940 V8 85. Bought the car in Sept 2014. Always had a hard rumble accelerating from 0 to 45 about a week after purchase. I replaced entire exhaust system and it cut the noise level by 40%. It does not hurt between my ears anymore. But It is still there. It purrs going 50 to 60. And the rumble is gone if I accerlate after 45mph. but still there below 45. Are these two issues connected? Time is of the essence on these issues.
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42wagon |
05-08-2016 @ 4:46 PM
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Senior
Posts: 585
Joined: Oct 2009
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Those fans are not prone to breakage under normal circumstances. I'm going to guess that there is some sort of vibration in the engine as evidenced by the rumble that you describe. That vibration is causing the fan to move back and forth and eventually metal fatigue causes the blade to break off. My guess would be a bad thrust bearing and or bad crankshaft bearings. Maybe the engine mounts are loose and the whole engine is moving back and forth. Let us know what you find.
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40headaches |
05-08-2016 @ 5:30 PM
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Member
Posts: 36
Joined: Oct 2015
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So what would be the ft lb mark for the water pump mount nuts? Cause I just broke one of my water pump mounts, yep snapped it! Tightened a bit too much I'd say. Does anyone know if a '49 water pump fits a '40 motor?
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TomO |
05-09-2016 @ 7:12 AM
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Senior
Posts: 7256
Joined: Oct 2009
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A 49 water pump will not fit a 40 motor. Reproduction water pumps are available from most vendors or you may be able to buy a rebuilt pump from Skip Haney. Stay away from used pumps as they will very likely leak, either coolant or oil or both. If you need a core, I will give you a pair just for the shipping costs. http://www.fordcollector.com/water_pumps.htm The motor mounts should be tightened just enough to slightly compress the rubber cushion. Your fan may have had a bent blade. The bent blade will cause a vibration and eventually break. It would help if you could post photos of the broken fans. The 39-41 Ford fans are heavy duty items that seldom fail. You can only post one photo per reply on this Forum. Very large photos will not post either.
Tom
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40headaches |
05-09-2016 @ 9:29 AM
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Member
Posts: 36
Joined: Oct 2015
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The shinny black one is the victim from Sunday.
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40headaches |
05-09-2016 @ 9:30 AM
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Member
Posts: 36
Joined: Oct 2015
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up close of Sunday's fan housing
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40headaches |
05-09-2016 @ 9:33 AM
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Member
Posts: 36
Joined: Oct 2015
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up close of the blade. Now I see a dark area where it looks like it was seperating from the layers. My current intentions is to take both fans, blades, and pully to a machine shop and see if they are willing to help figure out what happened. Before I start removing the transmission and or engine from the car.
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TomO |
05-09-2016 @ 11:15 AM
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Senior
Posts: 7256
Joined: Oct 2009
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Thanks for the up close photos. Both of them show that the fan was cracked and probably bent. The rust is the tell tale. You will likely see a similar signs of rust on the other fan. Strip the next fan down to bare metal and use a crack detection oil or magnaflux to check the fan. Next spin it up on a lathe to check the balance. I would do this even if the seller says the fan is NOS and make sure that you can return a defective fan.
Tom
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40headaches |
05-10-2016 @ 12:23 PM
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Member
Posts: 36
Joined: Oct 2015
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Test drove the car w/ out the fan on, just a different hub. Did not go 100' when the rumble was heard in 2nd gear. I also felt a vibration in both clutch and gas pedals while sitting still and revving it up and staying at a moderate rpm. So I intend to remove the trans and go after the pressure plate area. I will inspect everything I get into. Thank you for the feedback. O and I am still have major starting issues. It sat for an hour after test drive and would turn over and over. But hey, why worry, no sense in starting it if I can't drive it. You can read that post story from the past.
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TomO |
05-10-2016 @ 4:05 PM
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Senior
Posts: 7256
Joined: Oct 2009
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It would be better to try to isolate the area where the rumble and vibration is coming from. I would pull the throttle out until I heard the rumble. Then short one plug at a time to see if it is a high speed miss. If all of the plugs are firing OK, then use a stethoscope or a long screwdriver to isolate the rumble. Check the generator, water pumps, exhaust manifolds and the bell housing.
Tom
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