My 74 spent most of the Penna. winter resting, awaiting the first signs of spring. On it's second outing this spring, the fan blade mysteriously starting to hit the shroud on the upper right area of the shroud. My quick remedy (I was out cruising) was to bend one of the blades which temporarly solved the problem.

I checked the fan blade...(not loose). I checked bolts on radiator and shroud...(all tight with no adjustment possible). I checked motor mounts......(tight, not broken or worn).

I am at a total loss how the fan is out of alignment? Has anyone experienced anything like this? The engine runs great with the exception of a whining sound from the tranny until it warms up.

My 74 has a 350 w/air, 4-Speed Manual Transmission with 27,000 origional miles.

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willz 1974 Stringray |img|http://img.villagephotos.com/p/2003-11/498355/HUWYN-willz74.jpg|/img|

Although i am new to this list and at the moment am a novice when it comes to Vette's i have worked on many cars and this can sometimes be caused by the fan coupling, if you grab the fan (when it's not running !) and see if there is any play, try moving it front to back, it may be hard to detect as the belt may hold it still, but see if you can feel any movement.

Gary

Willz- it sounds like your motor mounts are shot. This causes exessive flexing in the motor when you tach it up, mainly in gear.

Good luck.

Alan

I agree with the motor mount diagnosis. In my '76 I also noticed the power steering pump pulley touching the cross member...

Thoroughly check the radiator support itself. They are semi-notorious for rust problems. To expand on an earlier reply, loosen or remove the fan belt(s) to check for end play in the water pump and/or side play in the fan clutch. While the belts are loose, loosen the fan mounting bolts. The flange on the fan clutch may have slot mounts for different motor applications. The fan itself may have simply shifted off-center, thus causing the contact problem with the shroud. Try to re-align the fan, then tighten it down.

John

PS - Get that tranny serviced. $30 at JiffyLube and well worth it.

|UPDATED|4/26/2004 9:26:48 PM (AZT)|/UPDATED|

i can almost guarentee its the left motor mount. I put a new 250 shroud in a '69 chevelle and broke it a month later. Polyurethane mounts are available with "locks" so that if the mount fails, the motor won't jump.

by the way, buy a new fan or leave it bent. do notbend the blades back

Did you have the car up on blocks or jackstands? If the front cowl hangs a little from blocks at the door area, it kind of puts pressure in the core support area, which will in turn cause force on the shroud from the top down.
You may want to loosen the shroud a little, try to re-position. It usually settles back down after taking off of blocks or jackstands.
Anything that causes the front cowl of the car to have downward pressure on it, will result in the shroud mis-aligning a little, and the fan will hit it.

Transmission mount? I suppose if it failed and the tail of the trans shifted to the left side it could cause the fan to rub on the right side as you described.

For my very first clutch job I forgot to tighten the engine mounts back down. The first time I got down on it, the fan ripped the shroud off, starting at the top. What a scary sound that was.

Bill Folse
'70 LS5 Coupe

Thanks for your replies. I now have a lot of different avenues to look for around the fan blade. If I fail to discover the problem myself........ looks like it will be heading for the Chevy dealership for service.

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willz 1974 Stringray |img|http://img.villagephotos.com/p/2003-11/498355/HUWYN-willz74.jpg|/img|

im surprised your chevy dealership will touch your vette..

every time ive needed something done that requires too many tools and decided to try the dealership... they wind up sending me somewhere else.

Hi All,

Just an update on the fan blade mystery. It was a motor mount that went bad which caused the problem. I did have to replace the fan blade also. The shroud was still intact so we left it alone.

Happy cruising again!!!!!!

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willz 1974 Stringray |img|http://img.villagephotos.com/p/2003-11/498355/HUWYN-willz74.jpg|/img|

Good to hear... now go try to break the other one.
A nice strong rev without the tap tap tap is like music to the ears.

Good job.

Alan

I broke a new set with my galaxie once..

both motor mounts, carbuerator linkage, and both hood hinges.

put in a new set and chains to hold it down

be wary of anyone using 5/16" or bigger chain to hold his engine down.

chances are that his car is scarier than yours.

In my mother's 68 Cornet, the left mount broke, the engine lifted, pulled the throttle cable tight, opened it wide open, engine lifted more, right mount broke, trans mount broke, and the engine rotated about 1/3 turn in the engine bay. Shut off the key to stop it, then cleaned my shorts out.

Ken,

And then Christine said GET OUT!!!

And I left.

Actually I disconnected the throttle cable, sat on the fender to lightly control the throttle with the hood open a bit. My buddy steered and we drove it home, very slowly. I put all three mounts in it and had it fixed by the time my folks got home. Teenagers! (Oh that was me) Real world stupid stuff.