Author Topic: Fan not centered in shroud and can't figure it out - 82 GMC  (Read 3148 times)

Offline kngslb

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Hi All,

I have been struggling trying to figure out a fan issue on my 82 GMC C10 shortbox.

The truck was a basket case when I got it and have been restoring it. It has been taken apart over the years by previous owners as is typical of these old trucks.

The truck came from the factory with a 4.1 six cylinder with AC. It now as a 350 out of a 76 GM truck and no AC..

I am having trouble with the fan not being centered (top to bottom) in the shroud.

I have put an aftermarket transmission mount in it and new frame stands for the motor mounts.

I have a brand new fan shroud which matches exactly to an older fan shroud I picked up from a 80's Chevy truck. 

The radiator rubber mounts (top and bottom) are new as well.

I went to the junkyard yesterday and found a Chevy truck to look at the motor mounts and they looked the same as mine.

The core support bushings look newer and look to be correct.

I put a new long water pump on it when I rebuilt the motor.

I have a 19" fan for it but I will need to put a 17" on for a fan to fit which does not seem correct.

Any ideas if this should have a 18" or 19" fan?

The center of the fan looks to be about 2" too low.

I am calling the transmission crossmember company tomorrow to verify I have it installed the right way but today I took the transmission rubber mount completely out (which dropped the tranny down a couple inches at least) and it made the fan fit issue a little better but it still hits the bottom of the shroud.

Any ideas as I have beyond frustrated trying to figure this out? I have rebuilt other trucks and my Chevelle and have not run into a puzzle like this. Everything looks correct but clearly something is not due to the fan hitting.

Any help would be greatly appreciated.

Offline Irish_Alley

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Re: Fan not centered in shroud and can't figure it out - 82 GMC
« Reply #1 on: June 11, 2017, 06:29:44 pm »
different size motors (6 vs 8 ) will have different fan shrouds. was the old fan shroud centered before?
« Last Edit: June 12, 2017, 10:03:20 pm by Irish_Alley »
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Offline Stewart G Griffin

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Re: Fan not centered in shroud and can't figure it out - 82 GMC
« Reply #2 on: June 12, 2017, 08:15:19 pm »
The stock fan off my 305 is about 20"

And the stock 3 blade fan from the 4.3 is 19".

i want to say radiator/radiator core support bushings, but you say they are new.   Then i would look at the trans mount.  It may be the wrong one.

If the truck does not overheat with a smaller fan, then i wouldn't worry about it.   You could always go with an electric fan.