gr8corvette

It has been one of those days. As soon as I started on the 65 coupe, several things in the house broke.
Anyway, I bought a spacer to replace the fan clutch. From everything I have read, it is a pretty simple install. Just remove four bolts to remove the current fan clutch from the engine. Then remove the fan blades from the fan clutch by removing four bolts, then put the fan on the spacer and put the spacer on the engine with the four bolts.
Sounds simple, but the simple things are always hard for me!
I got the four bolts off. Three of them were only a little more than hand tight, but the fourth bolt on the bottom was just as irritable as I am now. I finally got all four bolts off in only 30 minutes (not counting the times I was interrupted to go fix things in the house). I thought the fan clutch would slide right off, but it is holding solid to the water pump (or whatever that thing is).
What do I do to remove the fan clutch? Is there a fifth screw somewhere? Could age have wielded the fan clutch to the engine? I pulled pretty hard but I was afraid to take a hammer to it. I figured if I hit it too hard, the water pump might be damaged.
HELP!

JohnZ

The water pump shaft has a 5/8" diameter pilot that protrudes through the water pump pulley and fits inside a 5/8" diameter hole in the back of the fan clutch, to precisely center the fan clutch to the water pump shaft. The pilot is probably "stuck" (hi-tech word) in the hole in the fan clutch; be patient and work it loose with a rubber mallet or small dead-blow hammer, and it'll come apart.

Make sure the hole in the back of the new spacer is a tight fit on the water pump pilot shaft so it's properly centered; 1971-up water pumps had a 3/4" pilot shaft and their fan clutches/spacers had a matching 3/4" hole for the pilot. You do NOT want to install a spacer with a 3/4" hole on a 5/8" shaft.

GUSTO14

Allan, take a rubber mallet to it and gently tap it as you rotate the assembly. The water pump shaft does slide into the back of the clutch unit and can be stubborn. You are wise to approach it carefully.

By the way, if you do get the fan to bolt to the spacer and the water pump, that thing is gonna howl as the engine rev's. The fan was not designed to spin any where close to engine speed and it's gonna use some healthy power to keep up with it. Typically folks will substitute a flex fan for that reason.

Good luck... GUSTO

SWC Tim

Protect your radiator with towels or something, so as you knock it loose it doesn't damage the radiator.
Tim

gr8corvette

Wise is not a word people generally use to discribe me!

I did not get the flex fan yet. If this works, I plan on getting the flex fan later. From the description of the effort to take this on and off, I wanted to see the the effect. If it cools the engine a little more, I will get the flex fan. If not, I will put the fan clutch back on. I do not plan on hitting above the 4000 RPM mark prior to getting the flex fan due to the stories I have read about the stock fan flying apart.

LouieM

BTW when it comes time to put things back together, it can be a pain to bolt things up to the water pump. Instead of bolts, screw studs (bolts with their heads cut off) into the four water pump holes so that you can hang the fan on to them. Then replace the studs one by one with your bolts and voila everything is back together with minimum of cursing.

KC66

Just so you know the spacer for a clutch fan and a flex fan is different. I use a spacer on my clutch fan with no problems.

KC

gr8corvette

??? This is the first I heard that. Does that mean I bought the wrong spacer? None of the spacer ads mentioned this, so how do I know which to buy, or even which I already bought?

MikeM

You know by comparing the bolt hole spacing between the water pump and the clutch holes in the fan blade.

I've never seen a spacer that adapts a clutch fan, fan blade, straight to the water pump. That doesn't mean they don't exist.

midyearvette

oh yeah mikem they do exist and i have removed them from several cars in the past because some of the fans designed for the fan clutch only have a max. rpm rating of 4000 rpm....something to think about
as far as the op not going over 4000 in his original post, good luck with that!........

KC66

Look at LIC online part #24-30R, there is a picture. The difference is the water pump bolt pattern is smaller than the bolt pattern of the fan that bolts to the clutch. You will see what I mean when you unbolt the fan fron the clutch. If the spacer you got is just a cylinder shape with elongated holes on the end, it for a flex fan. They make those in different thickness also 1/2", 1" and 2". If replacing a clutch fan you need a 2" for a flex fan. Sorry I dont know how to link the LIC part to the thread. KC

MikeM

:d:d

larrywalk

Having done something like this in the past when I was stationed at MCAS Yuma with a triple black '65 without A/C - don't do it. I converted a fan clutch hub to direct drive with a couple of through bolts in holes that I had drilled - it howled like a banshee and really didn't help the cooling problem!

If you do decide to proceed with this approach, you will need to use a flex fan to even fit on the adapter/spacer, and then, it still won't work very well with improving the cooling. Instead, just buy a new stock fan clutch hub like I did (go to a 7-blade stock fan if you only have a 5-blade), get a good stock replacement aluminum radiator, and seal up all the gaps which let hot air back-flow (recirculate) into the radiator.

Also, check your timing and ensure that you're using full manifold vacuum advance to the distributor and have a full advance curve.

toddalin

The operation of one will not be indicative of the operation of the other due to entirely different designs.

gr8corvette

I am finally finished putting the spacer on. What a PIA! Those who said they can do it in ten minutes must need to replace their watch batteries.
I finally figured out how to get the clutch fan off. I tried prying it off, but could not get a screw driver in between the fan clutch and the water pump wheel. After a lot of cursing, I finally managed to get a putty knife in there with a lot of pounding from a rubber mallet. Then I put the screw driver between the putty knife and the water pump and pounded on the screw driver until the fan clutch started to move. I went all the way around the clutch doing this so I would not bend anything. The fan clutch finally came off, but I will need a new putty knife.
The fan came off the fan clutch easily and I put the fan on the spacer easily. That part was not a problem. Then I went to put the the spacer on the water pump. This was another PIA. The spacer does not slide onto the water pump pip and I could not force it on by pressing. I figured as I tighten down the screws, the spacer would go on the pip. Turns out the bolts that came with the spacer were too short to do that. I tired the original screws, but they would not work with the way the spacer was designed. So, I put the spacer on crooked to get the screw hole closer to the water pump, put a bolt and lock washer on the spacer, and the bolt was still too short. So I took the lock washer off and put the bolt back in and got the threads to catch. Did this with the holes on either side and ended with the last bolt, turning each of them a little and moving to the next one, so that it would press down evenly. I finally got it all the way on and then removed the first screw so I could reinstall it with the lock washer. That did not work as this little extra thickness made the bolt too short. I had to take the lock washer with two pliers and bend it so the ends met, rather than being slightly offset. I reinstalled the bolts one at a time and was finished!
Now for the test drive. I started the car, I did not hear the roar that many people talked about, but I did hear a ticking sound (best i can describe it). I think I leaned on the AC fan belt cause it is now a little loose and I think that is the source of the sound.
Anyway, I got in the car and drove slow (20 to 25 MPH). The engine never went above 190 with the AC on. Almost success! Next I went to a parking lot and let it sit with the engine idling. It went up very slowly, but it did go up. When it got to 220, I put it back in drive and the temperature went back down to 190 while driving with the AC on at 20 to 25 MPH.
So, the conclusion is that the spacer pulls more air through the radiator at slow speeds than the fan clutch, but not enough to keep it cool while idling at a stop. Therefore, the answer to my problems is not a spacer.
Next I am going to try a larger puller fan (I already tried a 10 inch pusher that made absolutely no difference, even with the clutch fan still connected). Now I know everyone on another thread told me to just go directly to a DeWitts radiator. I will probably end up doing that. However, in the mean time, I am incrementing the trouble shooting bit by bit. Yes, I know this is taking more time and probably a lot more money than if I just bought the DeWitts radiator and fan to begin with, but this way I am having "fun" learning about my '65 Coupe. Fun is defined as sweating your @$$ off, peeling the skin off your knuckles, and cursing a lot! For someone that sits at a desk all week, this really is fun.

Frankie the Fink

If you bent the ends of the lock washers even they are no longer lock washers

gr8corvette

I couldn't get them on other wise.
I have always wondered about that. It is one of the curiosities of nature. When you tighten them unmodified, they end up even and function as lock washers. However, if you even the ends before tightening, then they are not lock washers. When installed, they are exactly the same either way.

Another curiosity of nature is how eating a five ounce cheese cake can make you gain several pounds. This just defies the laws of nature!

MikeM

Using a rubber mallet was your first mistake! If you want to move something that is stuck, learn how to use a steel hammer.

toms silver 60

Alan, you could have saved all this trouble by telling Frankie you had some of that yellow Mexican " beer " and he would have rushed over there....Just keep family sheltered inside the house if he wore his speedo. When he got done with that, he could adjust your 61 wipers...
Go ahead and get the flex fan whether you use ethanol contaminated fuel or not....

6T7L71CPE