Mudderoy
07-01-2009, 03:54 AM
I recently upgraded my fan clutch from a stock fan clutch to a Grand Cherokee fan clutch. It is NAPA part # 272310. It was about $43 with tax.
I started by removing the bolts holding the mechanical fan shroud.
I pushed the shroud back to wards the fan and the clutch. This gave me just enough room to remove the nuts holding the fan and the clutch.
http://xjtalk.com/images/special/jeephdfanclutch2.jpg
After removing the fan and clutch I laid it next to the new heavy duty clutch to compare. You can see the diameter of the heavy duty fan clutch is quite a bit larger.
http://xjtalk.com/images/special/jeephdfanclutch3.jpg
Hard to compare, so I removed the fan from the old fan clutch.
http://xjtalk.com/images/special/jeephdfanclutch4.jpg
Now to compare the height, this is the really important part since wider, taller, etc.. means closer to the radiator. As you can see there isn't that much of a difference.
Installation was easy. Mount fan to new fan clutch, then put the fan (AND SHROUD) in and put on the four nuts and tighten. I used a big long flathead screwdriver to hold the fan pulley in place while I tightened the nuts.
Now for the test drive.
http://xjtalk.com/images/special/jeephdfanclutch5.jpg
After about 5 minutes at 75 to 80 mph on I-10 coolant temps rose above the favored 210. Air temp was in the high 90's, 97, or 98. My "prior to the HD fan upgrade" test drive I was only able to drive for about 3 minutes before hitting the first hash past 210, 222.5 degrees. So this was an improvement!
http://xjtalk.com/images/special/jeephdfanclutch6.jpg
When I exited to turn around and come back down I-10, I pulled over to get a better picture of the temp gauge. This is more of a head on shot, so you get a better idea of the temp. I'm mid way between 210 and 222.5. So about 215/216 degrees.
The A/C feels cooler and the Jeep's performance is snappier. Before when it would get over 210 degrees you could feel it get slightly sluggish.
Now I have to stress that this upgrade was done on a 1998 HO 4.0L engine. From what I have read there may be some space limitations on the Renix XJ models. I would recommend taking the bolts off your shroud and then putting the new HD fan clutch next to the old to verify that you'll have the room to install it, otherwise you may have to remove your radiator, mount your HD fan clutch and reinstall the radiator.
I did not, I had plenty of room.
The HD Fan clutch is supposed to turn 70% to 90% of the shaft speed, as opposed to the 60% to 70% of the OEM XJ fan clutch. The one NEGATIVE thing I can say about this is that the clutch SCREAMS past 2800 rpm. I'll get a video and post it up here soon. With the exhaust, mudders, and stereo on it is hard to hear. My main concern was something was going to come apart, but after checking all my bolts I'm not concerned and I don't mind the scream as much.
I started by removing the bolts holding the mechanical fan shroud.
I pushed the shroud back to wards the fan and the clutch. This gave me just enough room to remove the nuts holding the fan and the clutch.
http://xjtalk.com/images/special/jeephdfanclutch2.jpg
After removing the fan and clutch I laid it next to the new heavy duty clutch to compare. You can see the diameter of the heavy duty fan clutch is quite a bit larger.
http://xjtalk.com/images/special/jeephdfanclutch3.jpg
Hard to compare, so I removed the fan from the old fan clutch.
http://xjtalk.com/images/special/jeephdfanclutch4.jpg
Now to compare the height, this is the really important part since wider, taller, etc.. means closer to the radiator. As you can see there isn't that much of a difference.
Installation was easy. Mount fan to new fan clutch, then put the fan (AND SHROUD) in and put on the four nuts and tighten. I used a big long flathead screwdriver to hold the fan pulley in place while I tightened the nuts.
Now for the test drive.
http://xjtalk.com/images/special/jeephdfanclutch5.jpg
After about 5 minutes at 75 to 80 mph on I-10 coolant temps rose above the favored 210. Air temp was in the high 90's, 97, or 98. My "prior to the HD fan upgrade" test drive I was only able to drive for about 3 minutes before hitting the first hash past 210, 222.5 degrees. So this was an improvement!
http://xjtalk.com/images/special/jeephdfanclutch6.jpg
When I exited to turn around and come back down I-10, I pulled over to get a better picture of the temp gauge. This is more of a head on shot, so you get a better idea of the temp. I'm mid way between 210 and 222.5. So about 215/216 degrees.
The A/C feels cooler and the Jeep's performance is snappier. Before when it would get over 210 degrees you could feel it get slightly sluggish.
Now I have to stress that this upgrade was done on a 1998 HO 4.0L engine. From what I have read there may be some space limitations on the Renix XJ models. I would recommend taking the bolts off your shroud and then putting the new HD fan clutch next to the old to verify that you'll have the room to install it, otherwise you may have to remove your radiator, mount your HD fan clutch and reinstall the radiator.
I did not, I had plenty of room.
The HD Fan clutch is supposed to turn 70% to 90% of the shaft speed, as opposed to the 60% to 70% of the OEM XJ fan clutch. The one NEGATIVE thing I can say about this is that the clutch SCREAMS past 2800 rpm. I'll get a video and post it up here soon. With the exhaust, mudders, and stereo on it is hard to hear. My main concern was something was going to come apart, but after checking all my bolts I'm not concerned and I don't mind the scream as much.