OEM cooling system fan upgrade?

drfd74

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I am considering installing a class 3 rec. hitch on my 07 KJ & also a mopar cooling fan upgrade kit to make it up to spec. for trailer towing. My rig has
3.7/ auto/ 4X4-stock sport.
My question is, I checked the spec. sheet on installation & it is a real easy
job to do, but what I noticed was that the new fan drive is screwed directly onto one of the engine pulleys that has a threaded male shaft sticking out.
Since this unit is directly mtd. to engine does rob performance such as power, mpg., & so on or does it have a electronic free wheel switch?
My vech. has an extended warranty & I plan to move out of state and pull
a 4X7 utility trailer thru moderate mtn. areas. Would this upgrade be a good idea or overkill.
Any Ideas???
 

RageOfFury

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I'm not sure about the HD cooling kit robbing performance or not, but the 5000lbs that Chrysler says the KJ can pull isn't quite true. I wouldn't pull more than 3500-3700Lbs.
 

tjkj2002

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I'm not sure about the HD cooling kit robbing performance or not, but the 5000lbs that Chrysler says the KJ can pull isn't quite true. I wouldn't pull more than 3500-3700Lbs.
Well I wouldn't want to put 5k behind a KJ with a 42RLE and towing through the mountains here in CO,even with the HD cooling.Now I've pulled 4500lbs with my KJ from Ft Lewis WA to Ft Carson CO(not exactly flat by any means) without HD cooling but I do have a 28,000lbs GVWR AUX trans cooler and the 45RFE trans without issues(60-65mph max and locked out OD).I did pull 6200lbs for 30 miles,wouldn't want to do that again anytime soon without trailer brakes.
 

barryh

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HD Cooling fan Kj Liberty

The additional fan for the Tow Kit is a conventional Clutch-Fan that screwsto thefront of the Water Pump shaft. The regulation or coupling effect for this type of fan is controlled by the temp of the air flow through the radiator. If the temp is low the fan just slips or freewheels and couples up when temp goes up. I have only just bought my car and it has this kit as standard I suspect but it does have the Mopar Tow Bar. barryh
 

tjkj2002

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Does the electric fan stay mounted? Does the shroud get changed?
The HD cooling kit comes with a new electric fan,shroud,and mechanical clutch fan.Last I heard the HD cooling kits are discontinued,they where like $250 for the entire kit,heck the electric fan alone is over $470 alone if bought separately.I have installed a few of those HD cooling kits,took like 10mins max to install as it is just a few 10mm bolts(easy to get to also) and 1 connector.
 

kb0nly

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I am considering installing a class 3 rec. hitch on my 07 KJ & also a mopar cooling fan upgrade kit to make it up to spec. for trailer towing. My rig has
3.7/ auto/ 4X4-stock sport.
My question is, I checked the spec. sheet on installation & it is a real easy
job to do, but what I noticed was that the new fan drive is screwed directly onto one of the engine pulleys that has a threaded male shaft sticking out.
Since this unit is directly mtd. to engine does rob performance such as power, mpg., & so on or does it have a electronic free wheel switch?
My vech. has an extended warranty & I plan to move out of state and pull
a 4X7 utility trailer thru moderate mtn. areas. Would this upgrade be a good idea or overkill.
Any Ideas???

Its not the size of the trailer, you said 4x7, but the weight. I regularly pull around a 4x8 utility and usually it has 300-500lbs in it hauling tools or the snowblower or lawnmower around, etc... But i have had it loaded much heavier, 1500lbs roughly, it was a 2000lb rated axle so no problems there. And it pulled that like nothing was even there.

Also if your utility trailer has one of those foldup trailer ramps that makes a big difference for wind resistance and you will feel some tug from it. Otherwise i have pulled larger, a 5x12 a friend owns, pulled that loaded with about 2000lbs of lumber, plus trailer weight i was easily in the 3000-3200lb range as his date plate shows 1200lbs for the empty trailer weight. It made it snort a bit on the hills and i was glad i didnt have to pull it far, about 10 miles, because the trailer didn't have brakes and i didnt have a brake controller anyway. It's an OLD trailer that he put new axles and tires on, so it wasn't originally built with brakes back in the day. If it had brakes and i was wired for it with a controller it wouldn't have worried me at all.

Either way it never got hot and handled it like a champ.
 

kskj

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Wyckoff has the mechanical fan blade and clutch for the hd cooling. The kit I bought last year also came with the electric fan and shroud that I already had on the 04. But I think you might need the shroud yours might be smaller On the 06. I have a extra one for the 04 but I'm not sure if it would fit on yours.
 

ptsb5a

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I've got the towing package and engine driven fan on my '05. No electric fan to supplement the cooling. I didn't know I could have both. Does the electric fan mount fwd of the rad?
 

tjkj2002

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I've got the towing package and engine driven fan on my '05. No electric fan to supplement the cooling. I didn't know I could have both. Does the electric fan mount fwd of the rad?
Every single gas KJ has a electric fan as the prime air mover,HD cooling only adds a mechanical clutch fan as a cooling aid inconjuction to the electric fan at low speeds.With HD cooling the electric fan is in front of the mechanical fan,kinda hidden.If you do not have the electric fan you might want to find out when it was removed and by whom.
 

ptsb5a

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I'll take a closer look tomorrow. I've had the KJ since new. I was just expecting to see a pusher style fan on the outside of the rad, not between the rad and mech fan. Weird. Thanks for the head slap.
 

drfd74

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cooling fan upgd. quest?

The OEM kit in question:pT#82206937 $236.50 HD cooling upgrade
OEM rec. hitch PT#82207535 $146.78
Parts & info. ref. from : http://www.libertypartsstore.com/
I have a mopar copy of the upgrade kit instructions that show all details but I couldn't figure out how to dn- load views.(dunno)
THX for all the feedback,
drfd74
 

RageOfFury

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From what I've read, you can pull 2500Lbs without needing the HD cooling kit. I haven't installed the kit on my KJ because it's extremely expensive and I never see myself towing more than 1500Lbs.

But if you plan on pulling more than 2500Lbs, then HD cooling kit is a must.
 

sleeve

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Tow Ratings (from the factory)

Auto Transmission W/O Tow package = 3500 pounds
Auto Transmission W/ Tow package = 5000 pounds [when properly equipped]
Manual Transmission = 3500 pounds

I've towed plenty in my KJ and must tell you that once you get over 2000 pounds a trailer brake becomes a necessity in most cases. Towing Rules by State, An older version of the rules

Depending on what you are pulling you will want to read up on those rules.

Also - the HD cooling kit isn't all that great. The mechanical fan only really shines when you are manuvering a trailer around at low speed. The real items you should look at are a secondary cooler like TJ mentioned and [if you are towing heavy] a trailer brake controller.
 

J-Thompson

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think about what it does
as was stated it has a fluid that heats up and tightens a clutch when it expands
it pulls air based off of engine speed up to about 2500 RPM then free spins
last I checked highway speed in a KJ ,65 mph, puts it at about 2500 rpm
this would make it point less
then what about stop and go traffic this is where the heat really gets turned up right?
sure it does but your engine never goes much over 1200 rpm thus moving little air
to move this volume of air will take power
power takes gas ,it is the how much that I do not know

enter the electric fan
sitting still engine at 600 rpm the fan will still move the max CFM it can
and free spin at highway speed
thus making the electric fan better

so now ask me why do so many "trucks" come with mechanical fans
I figure some one wants to know so here is the bottom line
they are fool proof
they either work or do not work
water ,mud ect have no effect on them
this is why they came on Wranglers ,so you could beat the snot out of them
and they would keep on working
if you are like me and like AC in July while you hit the trails
then you end up adding an electric fan
 

kskj

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I bought the HD cooling kit just for offroading. I have never towed anything. The electric fan was just not enough for trips to Colorado. It would over heat at high altitude in 4 low. It happened two years in a row when I got over 11,000 feet. I installed the kit before I went to the safari in Ouray last year ( I did not want problems traveling with the whole group) and it did not get hot at all the whole trip. And used the ac in moab in july while offroading and it worked great.
 

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