HD fan clutch upgrade...

xj88superjeep

NAXJA Forum User
Location
NJ
Well, I've put together a "max-duty" upgrade for my xj, and the HD clutch was something I did alot of research on to make part of the upgrade. I found that a 97-98 zj with the 4.0 and W/O max cooling option has a heavy duty clutch that is a direct bolt on replacement. ($62 NAPA) The standard duty clutch spins 60-70% of shaft speed. The HD spins 70-90% of shaft speed. I like the idea of keeping the clutch fan over converting to electric because that makes it a redundant system so if your e-fan dies, you can still get home. The HD clutch pulls MUCH more air!!! It won't fix an overheating problem, but as an upgrade to a good system, it will keep the temps from rising. My buddy said it sounds like I swapped in a V8! I could not stop myself from smiling the whole way home. LOL
 
xjohnnyc said:
Caution... Don't get the severe duty clutch from the "max-cooling" package... It won't fit. (I TRIED) You might be able to do it if you remove the radiator to bolt it up, but thats a lot of work, and it would be so close to the rad that it would block more air than it is pulling. plus, if you break a motor mount, or if your motor flexes at all, it is gonna hit the fins. You want the HD that is only on the 97-98 zj WITHOUT max cooling!
 
Pharaoh XJ said:
I adjusted my stock fan clutch, I just decreased the coiled spring load so that it locks earlier & is partially locked at lower temps.

Thats where you disconnect the spring, rotate it 180 and reconnect, right?
 
Don't get the severe duty clutch from the "max-cooling" package... It won't fit. (I TRIED)
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What rad and water pump are you useing?
Was this on the 88? How much room between fan and rad with OEM/replacement clutch?
Is it just the clutch fins that come so close or are the fan blades close to. Can't find any dimension on the MC clutch and really don't want to buy one just to get them.
I'm going to do a complete coolant system replacement on my 01. Before the big Oct tow. .
I have tons of room between the stock fan and OEM rad. I was hoping to go alum 2 core and the Max Cool clutch fan. Thanks
 
This is the heavy duty clutch compared to the standard. the dimensions are the same except for the diameter. The fins are the same hight, there are just more of them. On the Severe duty, the fins are taller making it impossible to fit the clutch between the rad and the pulley. The fan location on the HD is unchanged from the standard, but I don't know where they would sit on the severe duty, as I could not mount it.

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Thanks for the pixs. After pulling the cowing on mine. I can see how really close they come. I will get the SD clutch anyway and see if any clearance can be had. Maybe taking a little off the mounting base or shorten the mounting standoff.
I could do the same with the water pump but them the WP pulley would need to be modified to retain belt alignment.
I'm also looking at importing a clutch off a Chevy I6. They had a real short one on that. If my memory serve me well.
Thanks for the help.
 
great info! off to get one after work... keep us updated with cooling progress if you dont mind - ie slow moving traffic or trails and highway or faster cruising speeds
 
aparke4 said:
great info! off to get one after work... keep us updated with cooling progress if you dont mind - ie slow moving traffic or trails and highway or faster cruising speeds

The new clutch works great! The only time it even thinks about going near 210 is after exiting the freeway, and sitting at a light at the bottom of the exit when the clutch fan is disengaged and idling, but the e-fan promptly puts the temp gauge in check, and she happily maintains a BELOW 210 average! gonna put in a 180 t-stat, and get an adjustable e-fan control that actually works, and get her down to an average temp around 200.
 
badron said:
Thanks for the pixs. After pulling the cowing on mine. I can see how really close they come. I will get the SD clutch anyway and see if any clearance can be had. Maybe taking a little off the mounting base or shorten the mounting standoff.
I could do the same with the water pump but them the WP pulley would need to be modified to retain belt alignment.
I'm also looking at importing a clutch off a Chevy I6. They had a real short one on that. If my memory serve me well.
Thanks for the help.

Well, I did get the severe duty clutch at first, but there is no way to fit it in there without removing the rad. If you shorten the studs on the pulley, there will be nothing to bolt the clutch to, and if you do bolt it in first, then install the rad after the fan and clutch, the clutch is so big, and so close to the rad fins that it would actually cause an airflow blockage the size of the diameter of the clutch. Not a wise trade off if you ask me. Plus, there will be less than an inch of space between the brand new fins of your rad, and that huge clutch. They probably wont warranty the rad with an imprint of the clutch in the fins if your motor ever flexes toward it.
 
i bought a torqflo heavy duty clutch and found the clearance was very high and would not fit without tilting the radiator. The fan blades also would not fit on the clutch without adding spacers/washers.

I went back to a torqflo standard clutch from autozone and that also requires a tilted radiator. At least I think so. The factory fan clutch has a lower clearance.
 
Just saw this thread and am a bit late but I wanted to ask you guys what your opinion is on an issue I just started having. Never done this swap and was about to since mine seems to be going. Not sure it's the fan though. The fan turns really slow when the engine in running and it is hitting the shroud to the point it sounds like bicycle spokes/cards kind of thing. But, the fan has tension when I turn the blade by hand which I thought was an indication that it isn't going? No leaking from the water pump and it isn't overheating (of course the electric fan comes on in Georgia summer heat. Do you think it is the fan clutch or should I look elsewhere? Thanks!
 
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