How to remove only the fan clutch on 620 1979 L20

[Fily]

Trying to install an e fan , remove fan , shroud and still fan clutch is on the way !!! Fan clutch came in one piece ( water pump, pulley and clutch) I can’t  find just water pump and pulley !!! Can I just cut the clutch with recip saw???

[]2eDeYe]

Yes. 

 

A cleaner solution is an early 240z water pump, added benefit of moving more volume as well. 

[datzenmike]

Just stay away from the pressed on pulley. I sliced my clutch off in pieces untill only the bearing was left. Sticks out about 1/2 - 3/4". If that isn't enough slice the bearing races off and use a grinder to trim further.

 

Here is with the bearing left on,  as there was more than enough room.

[distributorguy]

I grabbed the spare water pump off my '74 1800.  Easy.  

[datzenmike]

All I had were clutch fans. Most were from Z series trucks with the lager pump cavity and larger impellers...

 

Most L series...

 

 

Later larger displacement Z series and maybe L series with air con?...

 

 

 

[Fily]

Tanks !! I ended up putting the fan on the front of the radiator but seems like pushing air isn’t much effective than pulling!!! 

[datzenmike]

 I have one of each on my rad. Couldn't get two side by side so they overlap 3-4"

[JumboFett]

On 8/18/2019 at 12:36 PM, ]2eDeYe said:

Yes. 

 

A cleaner solution is an early 240z water pump, added benefit of moving more volume as well. 

What early year 240z, specifically? 70-71?

Any other water pumps compatible with the L20B?

I’m thinking about doing two 8” PermaCool fans, so I’m gonna need that extra space. 🙏

[datzenmike]

 

L16/18 and L20B pump

 

Z22 and Z24 (possibly Z20E) Note the deeper pump cavity and the taller impeller.

 

 

 

 

Early small pumps have the smaller clutch fan and blades (left) Larger capacity pumps have the larger clutch and fan (15") on the right. Some have 8 bladed. Check diameter of fan blade it may not fit the earlier stock shroud.

 

I have never heard that Z car pumps are larger. Could be. I have heard that Z car alternators are mounted farther forward so the fan pulley may not match L 4 cylinders???

[JumboFett]

2 hours ago, datzenmike said:

 

L16/18 and L20B pump

 

Z22 and Z24 (possibly Z20E) Note the deeper pump cavity and the taller impeller.

 

 

 

 

Early small pumps have the smaller clutch fan and blades (left) Larger capacity pumps have the larger clutch and fan (15") on the right. Some have 8 bladed. Check diameter of fan blade it may not fit the earlier stock shroud.

 

I have never heard that Z car pumps are larger. Could be. I have heard that Z car alternators are mounted farther forward so the fan pulley may not match L 4 cylinders???

Thanks, Mike!

Will I have to chop the fan clutch off any of those pumps too, or did the Z-block pumps allow for separation?

Right now I have an 8-blade fan / AC pump, so I’m not keen on destroying it if I have a substitute. 

[datzenmike]

Fan clutches are pressed onto the water pump and can't be removed. I have a larger volume Z24 water pump that I trimmed the clutch off of on my 710 and use two Subaru fans. I trimmed one once too close to the pulley and it popped off in use. Leave at least 1/8" or just cut down to the bearing.

 

 

 

 

 

[JumboFett]

6 hours ago, datzenmike said:

Fan clutches are pressed onto the water pump and can't be removed. I have a larger volume Z24 water pump that I trimmed the clutch off of on my 710 and use two Subaru fans. I trimmed one once too close to the pulley and it popped off in use. Leave at least 1/8" or just cut down to the bearing.

 

 

 

 

 

Nice! It looks like a really clean cut. What tool did you use for the job? A reciprocating saw with a deburring polish?

[datzenmike]

 

 

 

Unbolt it and score it across with a cutting wheel and just keep cutting and prying the pieces apart.

[]2eDeYe]

22 hours ago, JumboFett said:

What early year 240z, specifically? 70-71?

Any other water pumps compatible with the L20B?

I’m thinking about doing two 8” PermaCool fans, so I’m gonna need that extra space. 🙏

 

Wow time warp haha

 

Basically any of the early ones without the fan clutch. 

 

[JumboFett]

On 9/23/2022 at 7:22 PM, datzenmike said:

 

 

 

Unbolt it and score it across with a cutting wheel and just keep cutting and prying the pieces apart.

And then once it’s open it can be taken off the shaft, like carefully with a hammer or a press?

[datzenmike]

I just used a cut off wheel and kept trimming the soft aluminum away around the steel bearing. If careful, you can trim the bearing away also and cut the shaft shorter. I stopped at the bearing because i had the clearance I needed.

[JumboFett]

3 hours ago, datzenmike said:

I just used a cut off wheel and kept trimming the soft aluminum away around the steel bearing. If careful, you can trim the bearing away also and cut the shaft shorter. I stopped at the bearing because i had the clearance I needed.

I guess I’ll see more of what you know when I get to work and get inside that fan clutch. Thank you for all your guidance. 

[datzenmike]

I think the aluminum clutch part closest the pulley is pressed onto the bearing, then the inner wheel pressed onto the pump shaft, then the silicone oil and last the front cover is bolted on.

 

 

I scored the inner wheel and just snapped it in two. If that is the pump shaft in the center maybe a gear puller could be fitted. A smaller gear puller might pull the bearing off.

 

 

Not much room for a puller between the pulley and the back of the bearing. Here I've trimmed away the bearing but for the inner most race.