cooling system/zj fan clutch mod.

I have been getting ready to bolster my cooling system by buying the zj fan clutch. I bought the standard duty NAPA clutch that is recommended. In doing some further research I have become aware that there are space tolerance issues with this clutch and the CSF 3 core radiator, which I have in my vehicle. I am aware that new HD motor mounts help address potential clearance issues with combo of the CSF rad. and the zj fan clutch, but I personally do not want to rely on new motor mounts by themselves for a fix.


So I am wondering if some different radiator, a two core or even stock radiator, in combination with the zj fan clutch would be an improvement over the stock clutch combined with the CSF 3 row radiator. Any opinions on this? If so, what radiator would be recommended to be installed in combination with the ZJ clutch?

my opinion... stick with what you've got.
If that isn't going to happen,
get a $100 OEM replacement radiator from the auto parts store & the ZJ clutch. Put the clutch in while you've got the CSF out.
The ZJ clutch is noisy but it does indeed suck air. I haven't noticed any MPG difference or power difference but there probably is one. On the other hand... my electric fan almost never comes on. It has to be over 90 air temps & I have to climb a pretty good hill at low speed.

yossarian19 said:

my opinion... stick with what you've got.
.

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I think you are suggesting just leaving the stock clutch and the CSF rad in as they are rather than installing the zj clutch. I could be wrong though.

I've run many different setups. Full stock, stock rad with triple electric fans, CSF 3 core with stock clutch, triple electric fans, zj clutch. And my current setup which is the OEM HD rad, zj clutch and stock e-fan. My current setup is, by far, the most efficient at cooling. It runs about 10 degrees cooler than the other configurations.

Thanks a lot Captain! This is just the type of info I was looking for. What brand and model (and number if you have it) radiator do you have and where did you get it?

I have the CSF 3 row and just recently installed the thicker zj clutch as a preventative measure due to adding a winch that blocks a lot of the grill.

Anyway I wouldn't recommend it unless you have HD mounts, I have brown dogs and have no issues. I wheeled it hard right after installing with no issues, also noticed my trans temps stayed much cooler with the HD fan clutch.

whitexj98 said:

I have the CSF 3 row and just recently installed the thicker zj clutch as a preventative measure due to adding a winch that blocks a lot of the grill.

Anyway I wouldn't recommend it unless you have HD mounts, I have brown dogs and have no issues. I wheeled it hard right after installing with no issues, also noticed my trans temps stayed much cooler with the HD fan clutch.

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I have a winch cradle so I can take my winch on and off (obviously). I have not noticed any difference between my winch being on or off and my engine's tendency to run hot. I didn't even notice an improvement in going from the CSF 3 row from the stock radiator. My engine block has been flushed and my thermostat and clutch are good. Seems like the stock fans are just not moving enough air which is why I want to try the zj clutch.

Re: Re: cooling system/zj fan clutch mod.

Rod Knee said:

Thanks a lot Captain! This is just the type of info I was looking for. What brand and model (and number if you have it) radiator do you have and where did you get it?

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Got it from the dealership... Expensive, but it solved my 2 year battle with highway speeds overheating.

52080104AC

I ran a CSF three row with the ZJ fan clutch in my 94. No clearance issues, and did a great job cooling, and was loud.

I will say that I found out a few months after installing it that I was band-aiding another issue, which was a clogged cat that was causing overheating issues. So make sure you've got everything sorted before you go this route... I ran too cool after I fixed the cat.

TheCaptain said:

Got it from the dealership... Expensive, but it solved my 2 year battle with highway speeds overheating.
52080104AC

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Two years ago, after trying a Napa replacement and a CSF 3-core, I bought the HD Factory 52080104AC. It ended my overheating problems.

Did try a ZJ fan but it cut the freeway mileage and it was too noisy for a DD. It stayed engaged even when cold. No need since the stock fan clutch works OK
Would be fine for a trail only Jeep.

The Captain did this swap in the middle of summer where our temps are around 105 to 110 everyday in this desert. He has no trouble at all now going down the freeway or sitting at lights out here.He lives in the Lower desert( Palm Springs CA ). Heck coming to my house is(no joke) all up hill.Slow long grade, this is the best place to test your cooling system.


HTH

I looked into whether or not to swap in the ZJ fan clutch on my XJ pretty extensively earlier this year and I ultimately concluded (based on other's feedback) the following

>If you live in a state/location where the ambient temps in the fall and winter remain below 65* (approx.) the ZJ fan clutch may not let your Jeep warm up to efficient operating temp. during the fall/winter. In the summer the ZJ fan is a great mod keeping in mind it will be louder than stock and decrease your mpg (although if you're driving an XJ - who is really counting mpgs anyway?), but in the winter it's overkill.

>If you live in a southern state or hot location where temps generally remain at or above 65* (approx.) the ZJ fan clutch is fine to install since you don't have to worry about running "too cool."

I live in Virginia and we had one of the coldest winters in a long time last year (consistent days where temps did not rise above freezing). In the summer I am sure the ZJ fan clutch would be great (although my cooling system operates fine, and now I have wired a switch to my aux fan for those really hot days where I need a little extra cooling I can switch the fan on manually), but I know it would have kept my Jeep too cool in the winter, which is why I am just replacing my fan clutch with an OEM part (whenever I decide to get off my a$$ and install it).

A better mod may be adding an override switch to the aux fan. I have found this to work perfectly for me on those 95* plus days in the summer when the AC is pumping. Most of the time I don't need the extra air circulation, but it's nice to have. Whereas the ZJ fan clutch you don't have control over it, it's always operating.

scottmcneal said:

The Captain did this swap in the middle of summer where our temps are around 105 to 110 everyday in this desert. He has no trouble at all now going down the freeway or sitting at lights out here.He lives in the Lower desert( Palm Springs CA ). Heck coming to my house is(no joke) all up hill.Slow long grade, this is the best place to test your cooling system.HTH

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If it works in the Coachella Valley, in the summertime, it will work anywhere. Serious heat.