[The Original] Mechanical Cooling Fan/Clutch Upgrade for 1993-1998 Jeep ZJ V8 - JeepForum.com
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post #1 of 53 Old 08-24-2015, 10:58 AM Thread Starter
cubecompmtdx
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[The Original] Mechanical Cooling Fan/Clutch Upgrade for 1993-1998 Jeep ZJ V8

NOTE:I have considered this thread retired as the thread started out using a different setup than what is currently shown. Many of the replies in this thread are pertaining to flaws shown with the older parts (Ford YA220 fan blade on a Dorman 620-112 Fan spacer). The opening post has been updated to reflect the current parts list for this swap, however I am going to start a new thread on this subject with the current parts list to help prevent any confusion.

View the updated thread here:
https://www.jeepforum.com/forum/f13/2...r-fan-3714705/

This article applies to the following Jeep vehicles:


1993-1998 Jeep Grand Cherokee 5.2l V8
1993 Jeep Grand Wagoneer 5.2l V8
1998 Jeep Grand Cherokee 5.9 Limited 5.9l V8*


*The 5.9 Limited is equipped with an electric cooling fan from the factory. In cases where the electric fan motor, sensor, or wiring fails, the electric fan can likely be swapped for the mechanical fan setup presented herein. In addition to the mentioned part requirements, the 5.9 Limited will also need a 5.2l mechanical fan shroud, and associated upper-shroud mounting hardware. The mechanical fan will thread right onto the 5.9 water pump. Please note that this swap has NOT officially been tested on a 5.9.

This fan swap WILL NOT WORK on Grand Cherokees that have the 4.0L I6 as this motor uses a bolt-on fan clutch, and not a thread-on like the 5.2/5.9 V8's. I think the 4.0L's have an adequate fan from the factory.


When looking online at forums, you may find posts about Jeep ZJs with the 5.2l V8 running hot, overheating, or people complaining of poor idle A/C performance in hot conditions. This can be due to a combination of factors. A common cause of this is the stock 5-blade fan does not pull adequate airflow when running at low idle speeds. Also, the OE fan clutch by some is known to not engage until the coolant temp reaches 220F. Even with a severe duty fan clutch installed, fan noise can be extremely loud, and airflow can still sometimes be inadequate. Oftentimes, the 5-blade fan stays engaged all the time on hot days with aftermarket fan clutches as the fan does not provide enough airflow to lower the air temperature enough (aftermarket clutches tend to have a lower engagement temp), or enough drag to kick out the fan clutch when the vehicle returns to highway speeds. The lack of low-end drag also can make the fan take forever to kick out after cold starts. This results on poor highway fuel economy and performance as the fan is constantly on, providing additional drag at higher RPMs. The 5-blade fan is a dated design. Around the mid 90s, Ford and GM have worked away from the design in favor of nylon/plastic fans with higher blade counts. Ford started using higher-blade-count fans as early as the mid 80s on some vehicles, such as the Mustang. GM started using a new 11-blade "Tow Package" fan on the C/K trucks and SUVs as early as the mid 90s. This new fan designed flowed more air and was quieter. The 5-blade fan was dropped completely by the introduction of the GMT 800 Silverado/Sierra platform. As I have seen quite a few articles online of people swapping fans in other Jeeps such as the WJ Grand Cherokee and TJ Wrangler, I decided to look into a possible option for the ZJ V8. Basically, there are a few things I had to keep in mind when looking for a possible replacement fan option. I needed to make sure I could find a fan blade that measures 18 inches, so that it would fit into the ZJ's 19" shroud. Due to the ZJ V8 having a 19" shroud, I was limited on fan options. The GM fans mentioned previously won't work because they are 19" themselves. The replacement fan needed to flow more air at low speeds. The fan needed to sound not as obnoxious as the stock 5-blade fan. And last but not least, the fan swap needed to be inexpensive and require no major modifications to the existing vehicle. The following fan swap is a relatively simple bolt-in swap. Another thing important here is that the parts had to be easy to find.

Before you start modding your Jeep, let me get a couple of things out of the way. I an not responsible if you mess something up on your Jeep. This is a 100% experimental tutorial, and I will not be liable for damage to your vehicle. Also, the fan clutch is not the only thing that can cause high coolant temps or overheating. My Jeep has an almost 100% new cooling system on it. Everything except for the heater core and a couple heater hoses have been replaced within the past couple of years. Critical parts, such as the thermostat (195F), water pump, radiator cap, and radiator are all less than a year old.


Beta Videos:



Official How-To Video:
NOTE: I am in the process of posting a revised video. The present video above is for the previous revision of this upgrade.


Additional Videos:



As mentioned previously, I needed to find a fan design that was 18" in diameter and flowed more air vs the stock fan. After doing some looking around online, I found out that the 1993-1994 Ford Explorer 4.0L V6 uses an 18" fan with a screw-on fan clutch. I decided to go to the local Auto Parts U-Pull to grab one. I pulled the fan off of a 1993 Explorer 4.0 and threaded it onto a Grand Cherokee 5.9 water pump. It seemed to to fit just fine (the Jeep was missing its fan shroud), so I removed the old fan clutch from the fan, and bought the fan for $3. I had also went to AutoZone and picked up a fan clutch for $60. Once I confirmed proper fit of the fan, I purchased a new aftermarket OE equivalent for $25. To see the long journey of this experiment, please check out my long-term testing article at the link below:

http://www.facebook.com/notes/bikege...14208815477024

Parts Needed to do the swap:

  • Ford F3TZ8600C 10-blade fan (Aftermarket - Depo 330-55034-400), OE to 1993-94 Ford Explorers, Rangers, 4.0L V6 - Price Varies
  • TorqFlo 922794(*922793)/Hayden 2794(*2793) Fan Clutch - $60
  • Mounting Bolts for mounting the Fan to the Fan Clutch: M6-1.0 x10mm, Pack of 4 - $3 (Depending on your fan clutch, it might come with bolts, but assume it will not. I used bolts from an old fan from the JY)

*There are two models of severe duty fan clutches for the Ford 4.0L V6 for 1991-2001 or so... 2793 and 2794. I have a 2794. I have looked at a 2793 and cannot tell any noticeable differences between the two at this time. In reality, 2793 is what a parts counter catalog would pull up for any Explorer or Ranger using the 10 blade fan.

In terms of acquiring the fan blade, you may want to go used. The thing about the Explorer fans is they tend to get cracks in them. Now in theory, the metal fan body is designed to hold everything together in the event that the plastic wrapping around the fan body cracks. I would suggest to steer clear of fans with heavy stress cracks in them. I picked one from a 1993 Explorer and that was simply to test fit and function. I had the fan on for less than a week in relatively cool conditions. I purchased a Depo aftermarket fan from eBay for $25. Just look up a fan blade for a 1993 Explorer, simple enough. I have noticed some sellers don't list the actual DEPO part number in their listings, so looking up by part number alone may not find the best results. When you receive your fan, inspect it carefully. The first one I received had a chunk of plastic missing from one blade. The seller was quick to send a replacement. I purchased the fan from AutoAndArt on eBay. The DEPO fan is not as good of quality as a Ford OEM one, but it seems to be holding up just fine for me.

Tools Needed to do the swap:

  • 10mm socket
  • 13mm socket
  • 36mm or 1.5in wrench*
  • Decent sized hammer*

*Or a Fan Clutch Removal tool set, rented from your local auto parts store.

Steps to do the swap

First thing, your motor mounts need to be in good condition. Too much play can cause the fan to run into the shroud under hard acceleration from a stop. Also, I will not be responsible if you damage your vehicle. I have done lots of testing with this swap and have gotten good results. I suggest you do the swap on a cool engine. There is not much room to work with when the fan shroud is still in place. You can easily get burned. The first thing you will want to do is go ahead and loosen up the fan clutch bolt. This is where the 36mm wrench and hammer will come into play. The reason why you need the hammer is because the water pump pulley will slip when you attempt to loosen the fan clutch nut. The fan clutch nut on this vehicle loosens to the left when facing the front of the engine. Simply know it as righty-tighty-lefty-loosey. If you opted to get the fan clutch removal tools mentioned previously, follow the directions provided with the kit. If you opt to use the wrench and hammer, please follow along. Place the wrench into the nut on the back of the fan clutch. Now, give it a few good taps with the hammer. This will take several tries. Depending on how long the fan clutch has been installed, it may come off easy, or it may be difficult. As you tap the hammer against the wrench, the nut is slowly being loosened from the pulley. I try not to hit it too hard or use too much of a hammer to avoid any possibility of damaging the water pump bearings. Be patient. Once the fan clutch loosens up, do not thread it off just yet. Now, loosen the 13mm nuts holding the fan shroud into place. Once these nuts are removed, pull the shroud back from the radiator bracket. Now, carefully un-thread the fan clutch from the water pump. Be sure you have at least one hand on the fan blade at all times as you are un-threading it. The last thing you want to happen is the fan to fall off the water pump and land in your radiator. The 5-blade fan is heavy, and has sharp edges. It will likely cut through your radiator like a hot knife in butter. Once the fan is un-threaded from the water pump, pull the fan and shroud out at the same time.

Now it is time to prep the 10-blade Fan for installation.

You will need to assemble the fan and fan clutch together. Using your 10mm socket, assemble the fan and clutch together.

Make sure you don't install the fan backwards! The fan blade should note FRONT on the fan body side that faces the front of the vehicle.

Secure the assembly together using the M6-1.0 x10mm bolts.

Now that the "new" fan is ready for installation, reinstall it in reverse order of the steps mentioned previously. When reinstalling the fan shroud, make sure it sits inside the resting clips at the bottom of the radiator. Make sure that you tap the fan clutch nut with the hammer when tightening! (Or use the fan clutch removal kit to tighten) You do not want that fan to come loose from the water pump! When you start the vehicle, the nut will tighten up even more provided the fan clutch is tight on startup (you hear fan noise). Also, check all around the fan shroud to make sure the fan blade is not too close. IMPORTANT: Keep in mind that the gap between the fan blades and shroud will be smaller than before. The fan should set very close to the shroud on the bottom side. You want the gap to be larger up top vs down below. Under hard acceleration from a stop, the motor will flex up and toward the passenger side. There should be a decent amount of gap on this side of the shroud. You can move the shroud up a little bit if needed.

Once everything's back together, start the vehicle (before you close the hood). Your Jeep will have a new sound to it with a symmetrical 10-blade fan installed. This fan does get loud when the RPMs get above 2500, but boy does it pull some air. The only times you'll notice the fan engaging a lot is when it's hot outside and you're running the A/C.

Generally with this fan, a properly functioning cooling system with a 195F thermostat, and running A/C on a hot day, you'll notice the fan will engage hard when the temp rises to 205-210 when sitting. The fan will typically cycle off when the temp falls to 195-200. If you're stuck in traffic or stuck in a drive-thru for a long period of time (in 95+ conditions with A/C), the temperature may rise to 215 ( a needle width above 210). The Jeep ZJ is a hot running vehicle due to design(hence an 18 PSI radiator cap), and that's why you'll notice the fan coming on a lot in hot weather. In contrast, with my dad's 2005 Chevy 2500HD 6.0, also with a severe duty Hayden fan clutch, you won't hear the fan much at all in the same conditions unless you're towing.

Hope you enjoyed reading this. If you opt to do the swap, good luck! Let me know if you have questions.

Here are various images of the stock 5-blade fan and the 10-blade Explorer fan. Note, some of these may not be in order. I'm currently running the Explorer fan and plan to keep it on.

There you have it... a 10-blade fan upgrade. This fan performs significantly better than the stock 5-blade. The stock 5-blade pulls around 5MPH of air at the grille when fully warmed up, engaged, with the vehicle in park. The 10-blade pulls 6.3MPH under the same conditions.

Attached Thumbnails
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Last edited by cubecompmtdx; 04-10-2016 at 04:55 PM. Reason: Adding thread retirement note, as I plan to start a new, updated thread
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post #2 of 53 Old 08-24-2015, 11:31 AM
Technohead
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Nice write up but why don't you think the 5.2/5.9 fans are adequate from the factory? I've owned no less that four 5.2 ZJ's since they were first introduced in 93 and have pounded out over 600k miles. I have yet to have a cooling issue that could be traced to the fan. I have had cooling issues related to:

1.) Radiator fins vanishing
2.) Bad radiator cap
3.) Bad thermostat
4.) Bad water pump
5.) Obstructed air flow (bumper mounted lights)
6.) Cracked head/leaking head gasket

-Eric

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post #3 of 53 Old 08-24-2015, 12:58 PM
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Quote:
Originally Posted by Technohead View Post
Nice write up but why don't you think the 5.2/5.9 fans are adequate from the factory?
Maybe because some of us live where its 90+ degrees most of the year
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post #4 of 53 Old 08-24-2015, 02:04 PM
Boone96ZJ
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What U Pull it are you using in Huntersville...not any in Mooresville.

96 5.2 242 3" 32x11.5
https://www.jeepforum.com/forum/f13/1996-grand-cherokee-laredo-5-2-a-2570290/
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post #5 of 53 Old 08-24-2015, 02:50 PM Thread Starter
cubecompmtdx
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Auto Parts U-Pull off of Statesville Rd. It's minutes away from Walmart and Harris Blvd. It's a local chain with relatively nice people, unlike Pull-A-Part. They have many Explorers with the fans still intact. It's where I got mine from. Also plenty of Jeeps there.
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post #6 of 53 Old 08-24-2015, 02:58 PM Thread Starter
cubecompmtdx
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Quote:
Originally Posted by Technohead View Post
Nice write up but why don't you think the 5.2/5.9 fans are adequate from the factory? I've owned no less that four 5.2 ZJ's since they were first introduced in 93 and have pounded out over 600k miles. I have yet to have a cooling issue that could be traced to the fan. I have had cooling issues related to:

1.) Radiator fins vanishing
2.) Bad radiator cap
3.) Bad thermostat
4.) Bad water pump
5.) Obstructed air flow (bumper mounted lights)
6.) Cracked head/leaking head gasket

My Jeep has a new radiator, water pump, thermostat, radiator cap, and no airflow obstructions. IDK if the heads have any cracks. It runs like a champ. Head gaskets are fine also. The ZJ V8 does have an inadequate fan. I believe Chrysler even offered a TSB upgrade fan, though the TSB only applied to CA models.

Take a look at post #10 in this thread...
https://www.jeepforum.com/forum/f13/e...r-fan-3364770/

My Jeep has never overheated (blowing steam, etc) but with the stock 5-blade, temps will creep up when idling in traffic with A/C long enough, and A/C performance will get poor. I wanted something that didn't stay locked all the time during the summer. The Explorer fan setup is a little noisy when engaged, but even on 100F days, it freewheels when on the highway. A/C performance is also better.
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post #7 of 53 Old 08-24-2015, 03:51 PM
rburrow87
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Quote:
Originally Posted by Technohead View Post
Nice write up but why don't you think the 5.2/5.9 fans are adequate from the factory? I've owned no less that four 5.2 ZJ's since they were first introduced in 93 and have pounded out over 600k miles. I have yet to have a cooling issue that could be traced to the fan. I have had cooling issues related to:

1.) Radiator fins vanishing
2.) Bad radiator cap
3.) Bad thermostat
4.) Bad water pump
5.) Obstructed air flow (bumper mounted lights)
6.) Cracked head/leaking head gasket
I've had two '95 V8's and they both have/had issues when we start seeing 90+ degree weather here, or start crawling around offroad in the heat for a long time. The problem seems to be that the fan just does not move enough air until you get the engine RPMs up. It's not really an issue if you don't get stuck sitting still in hot weather with the AC on for extended periods, or do anything that puts a load on the engine without revving enough for the fan to do any good. The fact that the AC gets weak or nearly stops working when sitting still when it's very hot out points to inadequate airflow. Both Jeeps did/do this.

Both Jeeps had cooling system overhauls (radiator, pump, hoses, etc.) and I didn't use the same brand parts on my current one. I find it incredibly unlikely that they both have the exact same problem that would cause the exact same behavior when everything except the engine block has been replaced. My previous ZJ even got brand new heads (for other reasons) and had zero effect on the cooling situation. It seems that the cooling system airflow is just barely adequate for typical street driving situations, and anything more than that will put it over the edge.

I've been looking at switching to an electric fan setup so that it can actually maintain a decent temperature, but I think I'll try out this fan blade swap first.

Quote:
Originally Posted by cubecompmtdx View Post
My Jeep has a new radiator, water pump, thermostat, radiator cap, and no airflow obstructions. IDK if the heads have any cracks. It runs like a champ. Head gaskets are fine also. The ZJ V8 does have an inadequate fan. I believe Chrysler even offered a TSB upgrade fan, though the TSB only applied to CA models.

Take a look at post #10 in this thread...
https://www.jeepforum.com/forum/f13/e...r-fan-3364770/

My Jeep has never overheated (blowing steam, etc) but with the stock 5-blade, temps will creep up when idling in traffic with A/C long enough, and A/C performance will get poor. I wanted something that didn't stay locked all the time during the summer. The Explorer fan setup is a little noisy when engaged, but even on 100F days, it freewheels when on the highway. A/C performance is also better.
This is exactly what I experience with both my current and previous V8 ZJ. I even replaced all the same parts you listed, along with ensuring that all the air seals that go around the radiator were intact, or replaced if not.
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post #8 of 53 Old 08-24-2015, 03:56 PM
Boone96ZJ
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Quote:
Originally Posted by cubecompmtdx View Post
Auto Parts U-Pull off of Statesville Rd. It's minutes away from Walmart and Harris Blvd. It's a local chain with relatively nice people, unlike Pull-A-Part. They have many Explorers with the fans still intact. It's where I got mine from. Also plenty of Jeeps there.
well I know what I am doing this weekend when I visit the in-laws. And every time you said "stuck in traffic" and I saw you lived in Huntersville... I was like well he's either talking about 77, Exit 25 or 23 or Exit 18 or hell any where between Mooresville and Charlotte.

96 5.2 242 3" 32x11.5
https://www.jeepforum.com/forum/f13/1996-grand-cherokee-laredo-5-2-a-2570290/
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post #9 of 53 Old 08-24-2015, 04:39 PM Thread Starter
cubecompmtdx
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Quote:
Originally Posted by Boone96ZJ View Post
well I know what I am doing this weekend when I visit the in-laws. And every time you said "stuck in traffic" and I saw you lived in Huntersville... I was like well he's either talking about 77, Exit 25 or 23 or Exit 18 or hell any where between Mooresville and Charlotte.
In Huntersville, I don't get stuck in traffic too much. Now, I do work in Uptown Charlotte, and there's traffic there. The only spot in Huntersville that you may get stuck long enough to really test your cooling system is Statesville road near Exit 23 during the afternoon. On I-77, it's stop and go, but you're still moving along slowly. I've been stuck in traffic for very long periods in the following locations...

-Concord Parkway N in Downtown Concord.

-North Tryon St near UNC Charlotte.

Both of these areas were in the afternoon.

Good luck doing the swap! Since you're local to the area, you can come look at my setup if you wish. Just let me know if that's something you'd be interested in.

It seems like The ZJ V8's cooling system wasn't really designed with A/C in mind as that's usually when you'll have overheating issues related to poor airflow... when running the A/C.

If you're going to pull a used fan from an Explorer, take a look at that thick radiator in front of that V6. I guarantee you it's probably beefier than the one on a ZJ. Heck, it's funny to see how the cooling fan from a 4.0L V6 cools our 5.2L V8s better.

Last edited by cubecompmtdx; 08-24-2015 at 04:50 PM. Reason: Added additional information, and deleting a repeated word.
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post #10 of 53 Old 08-24-2015, 09:04 PM
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Thanks for the info. This will be on my list when I put a radiator in mine.


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post #11 of 53 Old 08-24-2015, 09:25 PM Thread Starter
cubecompmtdx
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No problem. My Jeep has a new Spectra Premium rad from AutoZone with their lifetime warranty. The 4-year-old Reach radiator blew up back in June while I was in Walmart. It had lots of deposits in it and I think the driver's side end-tank seal is what let go. If your setup functions just like mine, you'll literally be able to see the temp gage fall from 210 to 200 when the fan's engaged and you drive off from an intersection.

If enough of us get together and email Dorman requesting that spacer, they may consider selling it as a separate unit. Believe me, I have asked, but they stated there "wasn't enough demand for it". If they don't change their minds, then I guess eBay and Craigslist will get flooded with listings for the Dorman fans for the Mustangs as Jeep enthusiasts keep the spacers, sell the unneeded 9-blade fans, and convert their V8 ZJs to the Ford YA220 fans

Last edited by cubecompmtdx; 08-24-2015 at 09:27 PM. Reason: typo correction
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post #12 of 53 Old 08-25-2015, 09:00 AM
Boone96ZJ
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Quote:
Originally Posted by cubecompmtdx View Post

Good luck doing the swap! Since you're local to the area, you can come look at my setup if you wish. Just let me know if that's something you'd be interested in.

It seems like The ZJ V8's cooling system wasn't really designed with A/C in mind as that's usually when you'll have overheating issues related to poor airflow... when running the A/C.

If you're going to pull a used fan from an Explorer, take a look at that thick radiator in front of that V6. I guarantee you it's probably beefier than the one on a ZJ. Heck, it's funny to see how the cooling fan from a 4.0L V6 cools our 5.2L V8s better.
I live in Boone so 82 or 83 degrees is about as hot as my Jeep sees so I doubt I will do this fan swap. I probably ran the AC about 5 times this summer. I just wanted to know where a yard was besides Kannapolis or downtown Charlotte so I have something to do when I have to visit the in-laws.

96 5.2 242 3" 32x11.5
https://www.jeepforum.com/forum/f13/1996-grand-cherokee-laredo-5-2-a-2570290/
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post #13 of 53 Old 08-25-2015, 11:15 AM
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Man that's such a weird fan (stock one). The 4.0s have the fins evenly spaced IIRC...I suppose it would help while reaching down to do things...

Nice write up though!
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post #14 of 53 Old 08-26-2015, 11:52 PM Thread Starter
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Quote:
Originally Posted by zander21510 View Post
Man that's such a weird fan (stock one). The 4.0s have the fins evenly spaced IIRC...I suppose it would help while reaching down to do things...

Nice write up though!
Thanks! Yes, the 4.0l ZJ has a 17" 7-blade fan. Supposedly from what I have seen online, the 4.0L actually runs hotter than the 5.2L. This dated 5-blade fan is common to the ZJ 5.2L, as well as Dodge trucks and SUVs even up through the mid 2000s or so. Back in the 80s and through some part of the 90s, Ford and GM were running the classic 5-blade fan (with the same blade pattern) on their trucks, but switched to plastic fans with higher blade counts... because they cooled better. In fact, GM considered the black 11-blade fan used on later 90's C/K trucks the "tow package" fan for an obvious reason.

Now something else that's interesting (which I noted in the opening post) is that the 4.0L Wranglers used the 5-blade fan. And guess what? They had issues where they were running hot in the summer. There was even a TSB for an early 2000s model year for a 7-blade fan upgrade, but the upgrade fan was later pulled. Some have even swapped Explorer fans into their TJs and had better cooling, and A/C performance.

In a different thread, I discovered that Chrysler did seem to have a TSB issued for 1998 ZJ 5.2s, possibly for overheating with the stock 5-blade fan. The TSB called to replace the stock 5-blade with an Eaton-made 11-blade fan. The thread started out as an Explorer fan thread, but one of the users found the TSB fan on a ZJ in a U-Pull yard.

Here's the thread:
https://www.jeepforum.com/forum/f13/e...r-fan-3364770/

What's odd here is that the TSB only applied to California model 1998 ZJs.
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post #15 of 53 Old 08-27-2015, 01:52 AM
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The 4.0 is tuned to run hotter (lean) to get past emissions since it's such an old design.

My 5.2 has had no trouble cooling itself in 100+ degree weather since we bought it in 96.


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I heard someone yell "mall crawler" from the back porch. I'll go see who said that. Be right back.
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