fan question

[clutch]

hey guys, i was wondering about my fan. its one of them stock ones, you know with the clutch unit on the front of it. the shaft looks fine, spins straight and all. but the clutch it self wobbles.(on the shaft) ive heard they are filled with fluid. and if defective, how much hotter would say a auto store flex fan run me?

[thesnoman]

If it wobles, replace clutch soon. As far as flex fan, it will actually run cooler but a bit noisier too because it will always be engaged so to speak.

[clutch]

really? thats cool. also, do you need the spacer? or if clearance isnt a issue, does it matter?

[clutch]

also, what do you think about 18 or 19 inchers (fans) and what about the shroud? i can take it off, but its a new peice........

[Pelican]

You will need both the spacer and the shroud. The shroud allows the fan to draw air through the entire radiator, not just the part the fan sits behind while the spacer properly positions the fan in the shroud.

[thesnoman]

He should have a shroud now and will be able to reuse it. install a spacer that puts the flex fan in the same relative position as the old clutch fan.

[BWhite]

I still have the fan with new fan clutch , shroud , and 2 yr old full core radiator from the C20 454 Suburban I I once had . Any help ?

[76chevyman]

I bought a flex fan for my 76 chevy no clucth it was stock 4 blade fan and i went to a flex 6bladed fan and it ran hotter then the stock 4 blade. I will be coverting this to a clucth fan. But from my experiance with flex fans it didnt cool it down any. and yes it had a shroud and it was on the right way. I dont think its worth the extra money for a flex fan i would just replace the clucth and keep it stock. just my 2 cents.

Rich:burnout

[wyldman]

Skip the flex fan,or most of the aftermarket crap for that matter,it's not worth it.

Get a new (or used) fan clutch,and keep the stock setup.If you really don't want the clutch fan,then find a good used GM that doesn't use a clutch,and bolt it on.Most OEM fans will outcool a flex fan easily due to the better blade design.If the flex fans were that good,the manufacturers would have been using them long ago.

[thesnoman]

Flex fans are made of all different capacities. They actually were used in some OEM applications 20 to 30 years ago and the clutch fan was adopted not because it moved more air but because it was quiter overall and saved a bit of fuel. In a severe cooling environment, the proper flex fan would outperform a clutch fan by a wide margin. I have one on the wall here that came new on a 1 ton Ford van in the 70's. I have used it once or twice and it moves a very large amout of air and has 6 stainless steel flex paddles. I never cared much for the fiberglass ones.

[clutch]

ok. im thinking forget the aftermarket stuff. im gonna just get another clutch. hey B white, thanks but i got a new rad. new shroud , already, just need that clutch.

[75gmck25]

I've checked prices for the HD fan clutch for my '75 GMC and it was about $55 for the Imperial/Hayden brand from Autozone.

Bruce

[campi]

I also have a question about clutch fans, i have 80 k 30 temp always runs low up to first mark on guage no # when i first start truck in very cold weather fan starts runing with clutch fan should it do this cause its takes a long time to heat up seems fan is always runing is the clutch bad??? Thanks Campi !!!!!

[wyldman]

The fan clutch does have some residual drag,which will cause it to spin some,especially when cold.If you rev the engine up,you should NOT see the fan speed increase much,until the fan clutch kicks in.

You can also grab or spin the fan,with the engine off,and it should have very little resistance.If it is stiff,the clutch is bad.

It should not run cold though,even if the clutch is engaged all the time.Maybe a bad thermostat ? or gauge ?

[campi]

Thanks Chris the fan is stiff when engine is off also fan turns at same rate of speed al the time changed themostat and guage still runs cold so its probaly the clutch , also while plowing itgets warm enough to defrost windows but realy not warm enough to to suit me i know the older trucks do not get toasty like the new ones maybe i should take heater core out and have it checked?? do you think if i put a new fan clutch in the engine temp will be better?? rad is fine had it checked out ! what do you think? you solved problems for me before always on the money!! thanks I would like to solve this before it gets cold ! AS always thanks again Campi !!!!!!!

[wyldman]

If the thermostat is operating correctly,it should not run cold even if the clutch is siezed on.Are you sure the gauge is accurate ?? Maybe hook up a cheap gauge,or use an infrared temp gun to verify the operating temp.Are you using a 195 degree t-stat ? If you use a colder one,it won't run very hot.

The heater core could be plugged too,or the blend door is incorrectly adjusted.That would cause low heat output even if the engine is at the correct temperature.

[campi]

Thanks chris i will change the thermostat also going to change to a mechanical guage as soon as i get my truck back is getting painted now! also what is a blend door and were is it located need to ck it out i want to be able to plow in a sweat shirt insted of heavy coats the heat has been this way since i got the truck in 96 Its a80 chevy 1 ton is it posible to have really good heat in that yr truck??? ps its insulaled well all new door and window seals!! Thanks again Campi !!!!!

[wyldman]

Drop the glovebox,and follow the temp control cable to where it attaches to the blend door arm.Actuate the door,and see which way it moves from cold to hot.You can then disconnect the cable and move the door by hand to see if it travels any further,and if you get any more heat.While your in there,adjust the cable so the door is in sync with the temp lever.

[thesnoman]

Originally posted by campi
I also have a question about clutch fans, i have 80 k 30 temp always runs low up to first mark on guage no # when i first start truck in very cold weather fan starts runing with clutch fan should it do this cause its takes a long time to heat up seems fan is always runing is the clutch bad??? Thanks Campi !!!!!

Most fans will run for a bit (15 to 45 secs or so) on a cold start until drive fliud is redistributed back to reservoir. If it keeps running through out warmup then it needs to be replaces. On real cold day it may take up to a minute or 2 at a idle for fan to decouple.