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Fan Clutch Bad After 400 miles?

2K views 10 replies 9 participants last post by  StevenC 
#1 ·
Today I was wringing first gear out in the white caprice and somewhere around 5000 rpms i heard bangbangbang! I let off the gas quickly, pulled over, shut car off and popped the hood. I saw that the corners of my fan blades had a some marks on them, really strange, so I grabbed the fan and I could wiggle it back and forth. I'm guessing there's a sealed bearing in the back of the fan clutch because its moving where the shaft thats bolted to the waterpump goes into the back of the fan clutch, it's also very oily at this spot. I found a spot on edge my crank pulley that was nicked by the fan blade, so I know what the bang bang was.

This fan clutch has about 400 miles on it, it's a NAPA part. Have any of you guys had this happen to you or anyone you know because it's a first for me. I'm very lucky it wouldn't have been much longer before it sent my fan flying off. I'm going to get my money back for the part and invest it in a good flex fan.
 
#5 ·
5 grand is nothing for those, that's not what did it. Stock motors have those things on them and they 5 grand too. I've had one on a car for 150+ thousand miles and beat the hell out of the motor regularly. You have a defective part, not an improper usage.

Only lesson leanred is to keep your receipt.

K
 
#6 ·
Well I'm guessing that Ghettos fan sees 5000 rpm more often than the average grocery getter. :thumbup:

If the fan is constantly freewheeling (like when it cold out!) the small bearing that supports the entire assembly (which weighs at least 5 pds offset from the pump itself) is stressed to the max, I've had three come apart on me over the years from abuse. Last one was on my 84 Bronco II and nearly left me stranded on the highway as a result, luckily it was threaded on the pump snout and I could remove it easily and make it home. That vehicle was no high rpm power monster either, but I drove it hard because it was so underpowered and the abuse eventually killed the fan clutch bearing.

If you like, take the fan apart and replace the bearing with one designed for snowmobiles (packed with synthetic grease), it will last a little longer but with all that weight hanging and spinning offset from the pump snout they just don't handle abuse well. For the Bronco I just reused the mounting shaft and welded on a bolt on mounting plate for a stainless flex fan, I found that having less weight hanging off the water pump made them last longer too.

I put on a lot of miles on this truck in this configuration and during winter would remove the fan since the truck didn't need it anyway. I'm sure I'm not the only one who has had poor luck running a clutch fan on heavy duty vehicles.
 
#8 ·
hummm, on all of my vehicles I have a stock GM clutch fan, I have one on my 70 chevelle which sees 6,500 RPM regularly, and I have one on my daily driver that sees 5,000 RPM rpm Daily along with WOT blasts (i got a lead foot). I have not had any problems with one yet in the 6 years have driven them... makes me wonder if I am lucky... and with my new radiator I am thinking of putting a guard up... lol

-Leo-
 
#9 ·
I was driving across West Virgina in the Motor home and the 7 blade clutch fan lost a blade. I was doing about 60 and heard a ting and looked in the rear view mirror. I didnt see anything and watched the guages for several miles. Nothing appeared wrong and I hadnt seen anything in the mirrow so I didnt know what had happened. The first time I came to a stop it was shaking so bad you couldnt see out of the mirrors. I was afraid to shut it down thinking it might not restart. I limped to Ohio at a relatives house. It was shaking real bad but started right up. We went over that thing for 2 days trying to find the cause of the shake. I figured it had lost a piece of the harmonic balancer or something. It had a 400 small block in it. You really couldnt see the fan well from the top as everything is real tight. The way I found it was someone else was runnning it while I was laying under it. When he shut it off the fan came to a stop and the went backwards about 1/2 turn. Thats when I examined the fan real close and saw the missing blade. Its amazing how a 7 blade fan looks like none are missing when it has 6 left.
 
#10 ·
HAve you thought about going to an electric fan set up? You do seem to flog the hell out of your ride on a regular basis. If you went electric you will not need to worry about losing a flex-fan thru your hood and cooling system,same for the fan clutch. I have not seen one go bad like yours has done so I would also say that the part was just defective.Was it a New piece or was it a ReMan part. They do rebuild those things too and you may have got one with a worn shaft and the seal just did not stay mated to it.
 
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