I have 97 LX450 with 292K. I believe I have an original Fan Clutch. My mechanic told me that I need to replace it because because when I am at the stop sign or waiting for the light to change my AC is not cooling enough. It doesn't make any noises, truck never overheats. Question, is my mechanic correct or it's just not enough freon n the system. I replaced compressor and dryer last April. I bought Denso AC compressor. Thank you!
OEM Fan Clutch or Aisin Fan Clutch will be fine (1 Viewer)
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77mustard40
SILVER Star
I ran a new Blue Hub clutch for a year and half, worked fine. With the Texas temps insane this summer I pulled it and adjusted the opening when it was 105 in the garage (no need to heat the darn thing). Dumped the old oil and filled with one bottle of 15K, the difference in operating temps has been significant. My 80 is currently my DD and I was leaving the office in the evening in 103-108 with 18 miles of freeway driving and seeing my temp settle in at 190-194 at 75 MPH. I typically hit stop and go traffic at the 14 mile mark and temps would climb to the low 200's until I got moving again. After the fan clutch mod, my moving speed temps settle in at 186-188 and my stop and go temps climb to 191-195 which is basically 10 degrees cooler than unmodified. This is all with AC on. Fuel economy has dropped about .5 MPG on average, but hey I'm ok with it in these temps.
244,500 on the clock after a HG at 238,500 - TEQ radiator
244,500 on the clock after a HG at 238,500 - TEQ radiator
Question to the hive mind.
I've installed brand new Aisin blue hub clutch (along with a CSF full metal 3-row rad, water pump, thermostat, hoses if it makes any difference) as part of a base-lining process since my old rad has blown.
I did some tests on a hot engine - after a series of uphill runs to make sure the engine is hot. The gauge wasn't moving from its normal, almost horizontal position though.
What concerns me is that right after I shut down the engine I can rotate the fan without significant resistance. Is it normal or I should feel increased resistance in such conditions?
I will need to pull a 4000lb trailer for a couple of hundreds miles in a couple of days and don't want to be surprised.
I've installed brand new Aisin blue hub clutch (along with a CSF full metal 3-row rad, water pump, thermostat, hoses if it makes any difference) as part of a base-lining process since my old rad has blown.
I did some tests on a hot engine - after a series of uphill runs to make sure the engine is hot. The gauge wasn't moving from its normal, almost horizontal position though.
What concerns me is that right after I shut down the engine I can rotate the fan without significant resistance. Is it normal or I should feel increased resistance in such conditions?
I will need to pull a 4000lb trailer for a couple of hundreds miles in a couple of days and don't want to be surprised.
77mustard40
SILVER Star
The bigger concern would be your reliance on a dash gauge with a known flat spot, in most cases it won’t move to raise your alarm until it’s too late. Get yourself a ScanGuage or mobile app sender to plug into your OBDII port (assuming late model) so that you know your actual coolant temps.
Modifying the Blue Hub to adjust the internal opening and using a higher viscosity silicone takes about an hour start to finish, in my case the results have been positive based on ScanGauge displayed coolant temps.
Modifying the Blue Hub to adjust the internal opening and using a higher viscosity silicone takes about an hour start to finish, in my case the results have been positive based on ScanGauge displayed coolant temps.
Good point, I'll connect an OBD2 reader and check the temps.
Anyway, the question is if I should feel increased resistance if try to rotate the fan by hand or the clutch "hardly" engages once reaches certain temp rather than gradual increase of friction?
Anyway, the question is if I should feel increased resistance if try to rotate the fan by hand or the clutch "hardly" engages once reaches certain temp rather than gradual increase of friction?
1973Guppie
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Just buy an aisin off of rock auto........
1973Guppie
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not clutch related and not trying to derail the convo but the largest gain in cooling on my 80 I have seen when I vented the hood.
77mustard40
SILVER Star
I'm not sure if you can 'check' a fan clutch by judging resistance after the engine is warm but you peaked my curiosity. I'd say my modified clutch is easier to turn after shut down vs. cold, that said I didn't measure resistance just pulled on it with my hand. Take a look at the @landtank thread on modifying the clutch and decide if that's right for you. IIRC you can also buy his clutch pre-modified.
I've only got a few weeks of experience with my modified clutch and its been helpful in the Texas heat.
I've only got a few weeks of experience with my modified clutch and its been helpful in the Texas heat.
I’m in Phoenix. I was consistently running in the 208 range while stop and go driving around town and and on the highway. My AC was always ice cold and I never had any heat related problems, but didn’t like it running at that temp. I replaced the clutch with the same one in the Amazon link this summer and my temp dropped to 193 under the same conditions. I didn’t do any modifications to it. Best $80 I’ve spent in a while.
It depends. The clutch resistance is controlled by the temp of the air passing over it from the radiator.
About the only solid conclusion one can make is if the engine is confirmed running hot and the clutch is easy to turn. In this case the clutch is a problem.
@bj70alex : everything's already been said; the original fan clutch has lost most if not all of it's original fill of silicone oil by now. That oil is what makes the fan clutch work, no (or low) oil, no worky.
Tons of threads on modifying the original (or a new) fan clutch, here's one:
forum.ih8mud.com
Or, get one already modified:
Tons of threads on modifying the original (or a new) fan clutch, here's one:
Blue fan clutch mod...Thread has gone to hell, read at your own risk
History: On my first drive this summer after replacing my transmission I was having an overheat condition with the truck. On the following weekend while towing a camper it was real severe in the 230* range. After returning I was able to confirm that my Blue hubbed fan clutch was to blame...
forum.ih8mud.com
Or, get one already modified:
HD Fan Clutches
HD fan clutches tuned to flow more more air throughout the operating range to better cool the engine and lower the temperature of the AC during idling times. There are 3 variants: Modified Blue hub for NA engines Modified 1HD Orange up for Diesel engines. Modified SC Orange hub for Supercharged...
landtankproducts.com
I finally removed my Aisin blue hub to service it.
Thanks @jpoole and @77mustard40 for your information above.
I opened my hub that is about two years old and has about 30K miles on it. I was seeing temps spike at 206°F on an 82°F ambient day while climbing a hill at 75 MPH. It should not be seeing temps like that unless it's 100°F ambient.
I drained the hub overnight into a disposable plastic meat tray.
So, I temp tested the thermostat part of the hub in a pan of water. At 109°F it didn't budge.
At 126°F it didn't budge.
Finally at 134°F it finally started to open. The screws were already in the center of the travel.
So, I increased the water temp to 144°F and figured out where it was. Then I loosened the set screws and moved it so it was more open at 134°F than it was before. I expect it to open sooner on temps.
I put in about 55 ml of 15K CST silicone oil. Not sure if that's how much came out, but I filled the non-thermostat side of the hub so it was just under level full. Then I installed the thermostat half and tightened the screws with my impact screw gun. I used a #3 Phillips tip in my screw gun.
I cheated and didn't even loosen the belts to remove the hub. I put it back on and SLOWLY worked my way around the hub until all four nuts were Gutentite.
At first start up it roared like it should and after about 45 seconds it started to quiet down like it should.
I've got a 3 hour trip tomorrow on the same roads I did Thursday and Friday so it should be a good comparison except I will not be dragging a trailer this time.
Your data points helped me figure out a place to start. I was way overthinking this and kept wanting to make it much harder than it was. It still took me a couple hours to do this, but I go slow and sometimes it takes me longer to find my tools. I used my I.R. gun to check temps as I couldn't find the candy thermometer.
I used a disposable aluminum turkey pan, set the thermostat hubs in the pan, then ran full hot water from the tap into the pan. Our water heater achieved 120°F.
Then I boiled water in the teapot and added 170°F water until it got to about 164°F in the pan, then watched what it was doing.
Overall, I'm happy, but we'll see what the real world does tomorrow.
Thanks @jpoole and @77mustard40 for your information above.
I opened my hub that is about two years old and has about 30K miles on it. I was seeing temps spike at 206°F on an 82°F ambient day while climbing a hill at 75 MPH. It should not be seeing temps like that unless it's 100°F ambient.
I drained the hub overnight into a disposable plastic meat tray.
So, I temp tested the thermostat part of the hub in a pan of water. At 109°F it didn't budge.
At 126°F it didn't budge.
Finally at 134°F it finally started to open. The screws were already in the center of the travel.
So, I increased the water temp to 144°F and figured out where it was. Then I loosened the set screws and moved it so it was more open at 134°F than it was before. I expect it to open sooner on temps.
I put in about 55 ml of 15K CST silicone oil. Not sure if that's how much came out, but I filled the non-thermostat side of the hub so it was just under level full. Then I installed the thermostat half and tightened the screws with my impact screw gun. I used a #3 Phillips tip in my screw gun.
I cheated and didn't even loosen the belts to remove the hub. I put it back on and SLOWLY worked my way around the hub until all four nuts were Gutentite.
At first start up it roared like it should and after about 45 seconds it started to quiet down like it should.
I've got a 3 hour trip tomorrow on the same roads I did Thursday and Friday so it should be a good comparison except I will not be dragging a trailer this time.
Your data points helped me figure out a place to start. I was way overthinking this and kept wanting to make it much harder than it was. It still took me a couple hours to do this, but I go slow and sometimes it takes me longer to find my tools. I used my I.R. gun to check temps as I couldn't find the candy thermometer.
I used a disposable aluminum turkey pan, set the thermostat hubs in the pan, then ran full hot water from the tap into the pan. Our water heater achieved 120°F.
Then I boiled water in the teapot and added 170°F water until it got to about 164°F in the pan, then watched what it was doing.
Overall, I'm happy, but we'll see what the real world does tomorrow.
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I've started doing this as well. I loosen the fan shroud and slide the fan and clutch up and out of the top, passenger-side corner of the fan shroud/radiator gap from gently prying the shroud away from the radiator. These tricks make for very fast removal and reinstall of the fan and fan clutch.
I've used the opening/closing of the small port when setting temps and it looks like you were looking at the larger diagonal port and when it started opening? Maybe that's why you are looking at higher temps than the frequently mentioned 100 or 95 degrees F? It shouldn't really matter either way as you were familiar with the engine's operating temps and simply adjusted a little from where it had been which seems like a good idea. Opening 10 degrees earlier with fresh oil as well should yield a noticeable improvement.
Hopefully your top-end temps are just where you want them after this adjustment and you can ignore further fan clutch efforts for at least a few more years.
77mustard40
SILVER Star
Max temp I saw was 190. I rolled up to a road construction stop light and had to sit there for a bit. It spiked at 190 for about 10 seconds, then dropped back as was consistently 185-186 all 400 miles. Ambient temps were 77-90°F, no trailer.
I also got better gas mileage, although, I attribute that to no trailer.
No feel of loss of power due to a fan "running all the time". If anything, it felt a little better. I definitely heard the fan roar as I would pull away from an intersection. I had never heard that previously. However, I could also hear it let up as it came up to speed.
I think it was a win overall.
I will report again on my next trip.
surfpig
The Anti-Tech
Good thread. This issue pops up every once in a while... in my experience the Aisin blue hub clutch right out of the box will be much better that your 25+ year old clutch.
If you spend a little time and clock the opening temperature of the ports and replace the fluid with ~15k fluid (if I remember, it takes about 60mL to fill (2oz is about 48, right?).
I set mine to open up at about 180*. It sticks to that temp like glue. If I'm crawling, or going uphill and it's really hot or something, it'll rise to about 205-210.
If you spend a little time and clock the opening temperature of the ports and replace the fluid with ~15k fluid (if I remember, it takes about 60mL to fill (2oz is about 48, right?).
I set mine to open up at about 180*. It sticks to that temp like glue. If I'm crawling, or going uphill and it's really hot or something, it'll rise to about 205-210.
2 oz = 56 ml according to the bottles I bought.
One data point said they added 45 ml.
I added from the 56 ml bottle until the bottle did the first "empty ketchup bottle splooge" and then stopped. I'm guessing that to be about 55 ml. The non-tstat hub was almost level full sitting upside down on the table (in the best orientation to install the screws)
