JeepZJlover
NAXJA Forum User
- Location
- Marion, IA
Does anybody know bout this trick if so what's the part # what kinda benefit is it? Is it a direct fit ect? Thanks for the help guys
-
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Using zj fanclutch?
- Thread starter JeepZJlover
- Start date
magimerlin
NAXJA Forum User
- Location
- Flatonia, Tx
Do a search for "fanclutch upgrade" and you will find all the info you want on it. I can not remember the part # of the top of my head.
djgrayxj
NAXJA Forum User
- Location
- West Covina
Note from DJ
HD fan clutch upgrade
http://www.naxja.net/forum/showthread.php?t=962512l
OP by xj88superjeep on Aug 1-2008
Well, I've put together a "max-duty" upgrade for my xj, and the HD clutch was something I did a lot of research on to make part of the upgrade. I found that a 97-98ZJ with the 4.0 and W/O max cooling option has a heavy duty clutch that is a direct bolt on replacement NAPA part #272310 ONLY.
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
Post # 9
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 that’s 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 going to hit the fins. You want the HD that is only on the 97-98 ZJ WITHOUT max cooling!
Post #12
This is the heavy duty clutch compared to the standard. The dimensions are the same except for the diameter. The fins are the same height; 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. There is a comparison photo in this post
Post # 14
It's a direct bolt in for every year... They never changed.
.
Post # 22
These are the most common symptoms of a failed fan clutch:
· Leaking fluid - Oily build up around the bearing or thermal spring.
· Bad bearing - Seized, turns rough or has excessive play, (more than 1/4" at fan tip).
· Worn thermal spring - Spring is loose.
Some fan clutches will show no visible indication of a problem yet may still be faulty. The following may also indicate a faulty fan clutch:
· Fan spins excessively - Three or more times when hot engine is shut off.
· Poor air conditioning - At low speed or excessive high side pressures.
· Doesn't engage - Fan speed does not increase or "locks up" when the engine is hot.
· Does not disengage - Fan clutch won't slow down when the engine is cold.
·
Post # 30
After running this mod for a few months, I have to say that I am 100% satisfied! My cooling system was a wreck when I bought the Jeep. I actually thought for a while that I would just have to live with temps around 220+ as a DD. I could not be happier with the performance of the cooling system since the HD clutch install in the beginning of summer. I ran my A/C on max on the hottest days, and my XJ actually ran COOLER with the air on because the clutch fan did such a great job that the e-fan just iced the cake with an extra degree or two of cooler antifreeze. I actually wanted to run my air to keep the truck running cooler! LOL SERIOUSLY! Good luck to anyone upgrading. You got to get used to the sound of a jet turbine under the hood, but I have loved that sound from the beginning because it makes it sound like a bigger motor. LOL At first I felt a little drag on the motor, but I don't know if the ECU is compensating for my lead footed driving habits or I am just used to it by now, but I notice lots-o-torque and not any drag any
HD fan clutch upgrade
http://www.naxja.net/forum/showthread.php?t=962512l
OP by xj88superjeep on Aug 1-2008
Well, I've put together a "max-duty" upgrade for my xj, and the HD clutch was something I did a lot of research on to make part of the upgrade. I found that a 97-98ZJ with the 4.0 and W/O max cooling option has a heavy duty clutch that is a direct bolt on replacement NAPA part #272310 ONLY.
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
Post # 9
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 that’s 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 going to hit the fins. You want the HD that is only on the 97-98 ZJ WITHOUT max cooling!
Post #12
This is the heavy duty clutch compared to the standard. The dimensions are the same except for the diameter. The fins are the same height; 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. There is a comparison photo in this post
Post # 14
It's a direct bolt in for every year... They never changed.
.
Post # 22
These are the most common symptoms of a failed fan clutch:
· Leaking fluid - Oily build up around the bearing or thermal spring.
· Bad bearing - Seized, turns rough or has excessive play, (more than 1/4" at fan tip).
· Worn thermal spring - Spring is loose.
Some fan clutches will show no visible indication of a problem yet may still be faulty. The following may also indicate a faulty fan clutch:
· Fan spins excessively - Three or more times when hot engine is shut off.
· Poor air conditioning - At low speed or excessive high side pressures.
· Doesn't engage - Fan speed does not increase or "locks up" when the engine is hot.
· Does not disengage - Fan clutch won't slow down when the engine is cold.
·
Post # 30
After running this mod for a few months, I have to say that I am 100% satisfied! My cooling system was a wreck when I bought the Jeep. I actually thought for a while that I would just have to live with temps around 220+ as a DD. I could not be happier with the performance of the cooling system since the HD clutch install in the beginning of summer. I ran my A/C on max on the hottest days, and my XJ actually ran COOLER with the air on because the clutch fan did such a great job that the e-fan just iced the cake with an extra degree or two of cooler antifreeze. I actually wanted to run my air to keep the truck running cooler! LOL SERIOUSLY! Good luck to anyone upgrading. You got to get used to the sound of a jet turbine under the hood, but I have loved that sound from the beginning because it makes it sound like a bigger motor. LOL At first I felt a little drag on the motor, but I don't know if the ECU is compensating for my lead footed driving habits or I am just used to it by now, but I notice lots-o-torque and not any drag any
Danger Dave
NAXJA Forum User
- Location
- N Florida
My stock factory cooling system was worse than neglected when I bought it about 3 years ago. It never overheated, but it was marginal at best. When I had to replace the A/C evaporator I began to take a good look at the entire system. Everything appeared original on my 98. I attempted to flush the system before I began and I could not figure out why it seemed to have gobs of clay in the filler neck. It appears that the PO dumped lots of stop leak in the system. Flushing it out showed major leak in the radiator core to plastic tank seal. Since then I added a CSF 3 core radiator, new heater core, hi flow thermostat housing, name brand thermostat. After recovering from those expenses, I was researching water pumps when I was parked for several hours on a very hot day at a crime scene. While sitting and idling I began to smell coolant. Yep, the last part, the old water pump began leaking. I picked up a NAPA Severe Duty water pump (I had not heard of that before) and the 272310 fan clutch.
While there is a bit more sound from the upgraded fan clutch (it reminds me of the sound of my brother’s V8 Chevy 2500) it is not overwhelming. Perhaps my Flowmaster muffler masks the sound a bit. I have no worries of sitting on a crime scene or patrolling the beach at slow speeds any more. It now stays below the 210 mark after idling for some time and stays cool at slow speeds.
While there is a bit more sound from the upgraded fan clutch (it reminds me of the sound of my brother’s V8 Chevy 2500) it is not overwhelming. Perhaps my Flowmaster muffler masks the sound a bit. I have no worries of sitting on a crime scene or patrolling the beach at slow speeds any more. It now stays below the 210 mark after idling for some time and stays cool at slow speeds.
Cottontail
Three-De Off-Road
- Location
- Nashville, TN
When trolling the junkyard, how do you determine if it is max cooling or not?
cruiser54
NAXJA Forum User
- Location
- Prescott, Az
For $48 new and the high failure rate of fan clutches, why bother with the JY?
Cottontail
Three-De Off-Road
- Location
- Nashville, TN
Fair question....no answer! Didn't realize that fan clutches were as cheap as that.
I installed the ZJ fan clutch referenced here, along with going back to the stock 97+ mechanical fan. Everything fit well, and my cooling issues were finally resolved (horrid long story).
Do be aware that this is not a quiet option. You will get a significant amount of howl from the system. But, it is certainly moving the CFMs, and keeping things under control in 110+ degree heat.
I bought the fan clutch for a 97 ZJ from Autozone; standard, not extreme duty.
David Bricker / SYR
Do be aware that this is not a quiet option. You will get a significant amount of howl from the system. But, it is certainly moving the CFMs, and keeping things under control in 110+ degree heat.
I bought the fan clutch for a 97 ZJ from Autozone; standard, not extreme duty.
David Bricker / SYR
