• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

ZJ fan clutch

S

sumofatguy

NAXJA Forum User
Location
alberta
Hi everybody, I have a 2000 XJ. I was looking to replace my fan clutch since it is shot. I was hoping to upgrade the clutch to the ZJ one, and after searching the forums I'm finding conflicting results as to which clutch would work for me.

I've found 2 different napa part numbers (27230 and 272310) as well as different ZJ models ('97-98 4.0L or V8?) w/o max cooling (which is the same as HD?).

Any help as to which one would provide the best cooling option and bolt right in would be much appreciated. Thanks
 
mine did not fit without heavy modification, i believe it was the max cooling one. i had to put it in the lathe and machine down the cooling fins a bit for it to even get fetween the water pump pulley and radiator. it came on a 1994 zj 4.0l that i got for parts.
 
Not "supposedly" at all. It will not fit. The ZJ HD clutch is too long and the XJ fan will not bolt up without using spacers.

The '310 part number is the way to go. That p/n is for the ZJ Standard Duty fan clutch for the 4.0L.

Be advised though that you will get a ton of fan noise as the fan will now be turning at 80% instead of the stock, much lower coupled speed. I think that stock is 30% but, could be wrong about that number. In any event, you will get more air. And less mileage...

I replaced my ZJ fan clutch with a Ford two speed electric. Works fine and I picked up 2mpg on the highway.
 
I was going to do the Taurus fan mod, but it didn't fit with the wider 3 core rad and I didn't want to move it forward. I know the clutch is shot so I decided to just replace it with the ZJ one.

Is the mileage loss going to be noticeable? I'd assume at highway speeds the fan won't be engaged anyways
 
Also, after talking to napa here in Canada, the 272310 corresponds to part #A5549 if any Canadians are having issues. They said it is from the V8
 
sumofatguy said:
Also, after talking to napa here in Canada, the 272310 corresponds to part #A5549 if any Canadians are having issues. They said it is from the V8
Click to expand...

The V8 fan clutch wont fit. It has a different mounting than for an I6 jeep.
 
sumofatguy said:
I was going to do the Taurus fan mod, but it didn't fit with the wider 3 core rad and I didn't want to move it forward. I know the clutch is shot so I decided to just replace it with the ZJ one.

Is the mileage loss going to be noticeable? I'd assume at highway speeds the fan won't be engaged anyways
Click to expand...


FYI, I run a CSF 3 core and the Ford Fan fits fine when mounted into the stock mechanical fan shroud.

I did not move the radiator at all, just made sure the engine mounts were in good nick.
 
I didn't have to do any mods. Just bought the part number posted above from napa and bolted it all in. You may have to loosen the top mounts for the rad and tilt it forward to get it in though
 
sorry I meant that post to o-guage-steamer but I won't hijack you thread, sending you a PM now O gauge.

On another note tho, how do you like the zj clutch?
 
sumofatguy said:
I didn't have to do any mods. Just bought the part number posted above from napa and bolted it all in. You may have to loosen the top mounts for the rad and tilt it forward to get it in though
Click to expand...


I smell marginal engine mounts here... If everything is in good nick, it will bolt into place without issues.
 
o-gauge-steamer said:
Be advised though that you will get a ton of fan noise as the fan will now be turning at 80% instead of the stock, much lower coupled speed. I think that stock is 30% but, could be wrong about that number. In any event, you will get more air. And less mileage...
Click to expand...

Installed a ZJ fan clutch a few years ago and hated it. The fan noise and power loss was constant, loosing over 1 MPG during highway driving. It would over cool the engine on cold mornings. Not the ticket for a DD.
After a couple of months, I replaced it with a stock XJ fan and never looked back.
If you really need this, there is something wrong with the stock cooling system that needs to be addressed. The ZJ fan clutch is a band-aid.
 
lazyxj said:
Installed a ZJ fan clutch a few years ago and hated it. The fan noise and power loss was constant, loosing over 1 MPG during highway driving. It would over cool the engine on cold mornings. Not the ticket for a DD.
After a couple of months, I replaced it with a stock XJ fan and never looked back.
If you really need this, there is something wrong with the stock cooling system that needs to be addressed. The ZJ fan clutch is a band-aid.
Click to expand...

I kinda agree. I installed a ZJ fan clutch on mine because it was overheating up grades and getting hot in traffic. It stays frigid in traffic now, but still overheats up grades. Something else is wrong than just the fan clutch. I haven't noticed the loss in fuel economy though, but I don't drive mine daily.
 
lazyxj said:
Installed a ZJ fan clutch a few years ago and hated it. The fan noise and power loss was constant, loosing over 1 MPG during highway driving. It would over cool the engine on cold mornings. Not the ticket for a DD.
After a couple of months, I replaced it with a stock XJ fan and never looked back.
If you really need this, there is something wrong with the stock cooling system that needs to be addressed. The ZJ fan clutch is a band-aid.
Click to expand...

From what I understand, it should never "overcool" your jeep... If it's not up to operating temperature the thermostat is closed and no coolant is even making it to the rad
 
sumofatguy said:
I meant just to install the fan back over the studs. After its on, the rad fits back in normally with ~3/4" clearance.
Click to expand...

Glad to know.. I had tried to install this fan clutch on my '01 w/a 2-core Aluminum Radiator about 4 months back and couldn't get it to fit (over the mounting bolts as it was hitting the radiator) and it didn't even dawn on me to loosing the top of the 2-core Radiator and lean it forward to get it in...

I returned the clutch to Napa and went back to my OE clutch. What I'm interested in is pulling more air across the AC Condenser to help in cooling my interior when the AC is running. Have you noticed any change in that area?

Also, I hear a lot about the clutch making more noise... is it more noisy all the time, only during startup, during hot engine idling, etc? My wife's '03 KJ had a new HD Fan clutch installed last year when we put a new engine in... and it sounds kinda like a jet plane when you start it up f/the new fan clutch, but it idles down a bit and then becomes almost unnoticeable after a few minutes.
 
Redsnake said:
Also, I hear a lot about the clutch making more noise... is it more noisy all the time, only during startup, during hot engine idling, etc? My wife's '03 KJ had a new HD Fan clutch installed last year when we put a new engine in... and it sounds kinda like a jet plane when you start it up f/the new fan clutch, but it idles down a bit and then becomes almost unnoticeable after a few minutes.
Click to expand...

The ZJ clutch is loud all the time and is always pulling a lot of air, no matter if it is needed or not. It does not quiet down after a few minutes.
For a trail only rig, this may be good but for a DD, it gets annoying quick and if freeway driving is involved, it will decrease your mileage.
 
I have a switch in the cab for the aux fan to help cool the ac condenser and my tranny cooler if I'm crawling. I also have Lebaron hood vents, so my temperatures may be slightly different than yours.

As for the noise levels... I don't notice it being louder than stock. I don't own a jeep for the quiet smooth ride, that's for sure. The flowmaster and stereo are too loud to notice the noise the fan makes. Even with the radio off, I honestly don't notice any difference. Can't comment on mpg right now since I haven't driven it enough.
 
You must log in or register to reply here.

Similar threads

M
Some fan clutch air flow rate measurements
Replies
12
Views
3K
RCP Phx
R
J
Napa Fan Clutches
Replies
0
Views
232
JonnyCat63
J
F
99 XJ V8 Swapped, now door's will unlock but won't lock
Replies
3
Views
157
FreeRoller16
F
T
XJ shackle with custom springs question.
Replies
11
Views
206
XJlimitedx99
X
O
SYE vs Fixed Yoke spline geometry
Replies
7
Views
3K
RCP Phx
R
Back
Top