Mod New Blue Hub Fan Clutch?

[azlc77]

Recently purchased 97 LX450, with 129000. Finishing up PM including front axle rebuild. Thank you to all who have posted so much information. (as per the newbie guide and my wife, I am addicted and obsessed with this site)

I live in Phoenix and daily highs are around 110 now. Driving in stop and go traffic, the A/C is cutting off. I understand that this indicates that the engine is hitting 226 degrees. Will kick back in when I am not sitting still.

I have flushed radiator, heater core, and block, replaced coolant and thermostat and have a new blue hub fan clutch ready to go in.

My question is, Should I modify it per the Landtank mod or install it as is?

Simon

 

[miked]

I modded mine (blue) with 10,000 weight oil and turned the plate to make it open sooner. One of the best things I ever did. My a/c feels so much colder. Plus, it's worth it just to see the look on the guys face at the parts counter when you give him the part# for the oil. lol.

 

[arndog123]

X2 on modding it. I used 10K cst fluid on both my 80's as well w/ great results. You might even think about going even thicker. Another advice is to get a Scangauge so you know exactly how hot you're running.

 

[96r50]

I have 35ml of 15K in mine and the valve opens around 115F. Regardless of ambient temperatures so far this summer (50-90F), the truck runs at 182-190F.

Tools R Us is in Arizona and knows a lot about fan clutches. PM him if he doesn't post up here.

 

[azlc77]

Thanks for the advice. I will go ahead and modify it. Anyone know the part number for either the 10k or 15k weight oil?

 

[Lc80series]

You can reach Tools R Us on Copper State Cruisers. I'm sure you could meet him at the monthly meeting in Phoenix.

 

[miked]

08816-10001 10,000 cst

08816-06001 6,000 cst

08816-03001 3,000 cst

 

[Tools R Us]

For good PHX performance, your going to need more than 10K in a new type blue hub. Most here are seeing good results with 20K+ fluid. Don't change the valve setting, that actually reduces idle/low speed performance. I have fluid that your welcome to, PM me if you want some.

 

[landtank]

I've done this a bunch. The timing plates are all over the place on these unfortunately so not cooking them will give very unpredictable results. I first started down this road because a new blue clutch wasn't coming on at all. The timing was set so high that the clutch never came on. I've seen a couple others out of the box with a similar setting all the way down to where a prefer them to be set.

Just dumping is some thicker oil will likely help but it won't give predicable results. And advancing mine helped both idle and highway temps.

 

[Tapage]

Just dumping is some thicker oil will likely help but it won't give predicable results. And advancing mine helped both idle and highway temps.

confused here .. we down here see the worse hot conditions ( with 80 - 90% humidity ) that you can imagine .. so I'm interested on that .. but not sure now if the 20K oil will help at all . ?

 

[Tools R Us]

I've done this a bunch. The timing plates are all over the place on these unfortunately so not cooking them will give very unpredictable results. I first started down this road because a new blue clutch wasn't coming on at all. The timing was set so high that the clutch never came on. I've seen a couple others out of the box with a similar setting all the way down to where a prefer them to be set.

My experience dosen't agree, maybe a difference in testing method or Toyota just ships the "better" clutches to the west coast? Once I started using a fast acting contact thermistor and air to heat, they have shown typical for Toyota/Aisin consistencecy, most within 5F.

The "fan needed" air temp range is a wide range, so for one to not come on at all, it would have to be set +40F off. I haven't seen anything close to that.

Just dumping is some thicker oil will likely help but it won't give predicable results. And advancing mine helped both idle and highway temps.

I agree that advancing will help, but some of us need or prefer more, a better optimized clutch. The fully on section is designed to be much stronger for idle (more so on the earlier clutches). When the valve is cheated down this stronger valve opening is used at loaded cruise and idle, so will be stronger at cruise, but the same at idle heat soak.

Idle heat soak is the most important performance time for the clutch, little airflow over the rig, low drive pulley speed, big time fan need. If the valve is cheated down and significantly thicker fluid is added, at heavily loaded cruise (steep grades, towing,etc) it will be running on the highest opening, much more fan than needed and often slipping the belt. Been there, passed on the shirt.

If the valve is set close to stock or slightly warmer and significantly thicker fluid added, all valve openings become stronger, with idle being noticeably the strongest. When idle heat soaked and the throttle is increased, even slightly, it will drop back in a few seconds. Idle heat soak temp is greatly reduced, A/C performance noticeably increased.

The performance diffidence is not even a contest, a blind person could "see" it. Take a bunch of rigs, idling, in the sun. Walk by, the ones with stock set valves and significantly thicker fluid try to pull your laundry into the grill, can feel warm air blowing on your legs by the driver's door and the A/C is blowing cool air. The cheated valve lessor fluid units, you have to get close or behind the grill to feel significant flow, the flow out of the wheel wells is much less and hotter, the A/C is struggling to make warm air.

I have also done a ton of them, valves set all over and fluid from 6K to 30K. About stock set valves and significantly thicker fluid is the best preforming setup that we have found.

 

[landtank]

if you go back and read my initial thread you will see that the only time my truck was able to run within an exceptable heat range was at idle. As soon as I started to drive it it would run hot and ridiculously hot on hills.

I don't see how thicker oil would have helped that situation. In fact I think Cary tried your thicker oil solution to no avail on his clutch and finally advanced the timing to get things working correctly.

From cooking and evaluating a whole lot of clutches I can say that most are within a very tight range but there have been a few exceptions both hotter and cooler than where I typically set them.

Hell, I even had one sent to be that would never shut off and it literally cooked the oil.

Now I really don't see Toyota singling out clutches just for you but I do think you haven't seen everything that is out there either.

 

[landtank]

confused here .. we down here see the worse hot conditions ( with 80 - 90% humidity ) that you can imagine .. so I'm interested on that .. but not sure now if the 20K oil will help at all . ?

I only got into adjusting the timing because initially my brand new clutch would not engage at all. When I pulled over while the truck was up in the red zone there was no resistance to the clutch. Basically the larger second valve wasn't opening and allowing the fluid to flow to the drive side of the clutch.

I guess I could have just bought another one but I wanted to try and figure out why this new one wasn't working. So I started to fiddle around with the timing and eventually started to add thicker oil.

Since I started I've moved up to using 10k oil but if feed back shows that I should do an even thicker oil or change the timing I will.

The main reason for developing a timing procedure was to come up with some way to base line the clutch so you knew where you were at and could confidently make small changes and chart results. I can't say it's an ideal spot, just one to start from.

 

[Tools R Us]

if you go back and read my initial thread ....

I haven't read the early part that huge thread in a long time, IIRC it is is so full of conjecture that has now been proven wrong, that it's bordering on useless. I however did review the first couple of posts.

Your recommending using a dollar store 1" thermometer, 3" away from the thermostat and calling Aisin's calibration inaccurate?

I have sold thousands of those 1" thermometers, well not dollar store, but with some of the biggest names in the tool biz and significantly higher in price. They came in display boxes containing ~12 and ~24 of those in a case. We would open the tops, so they could be seen and calling the accuracy "about" would be generous, they read all over. Have done a bunch of playing with them and the accuracy, repeatability of them is somewhat better than a guess, maybe.

I also started out using the pan/liquid/thermo (digital) method, saw some inconsistency. Stepped up to a better/quicker acting thermistor setup and found that the clutch worked as a big heat sink, the liquid in the pan measured different temps depending on where the sensor was placed. Went to air heating with the sensor directly in contact with the thermostat, measuring the actual spring temperature. Using this method, the clutches that I have done have been pretty darn consistant.

Now I really don't see Toyota singling out clutches just for you but I do think you haven't seen everything that is out there either.

Agree, seeing how I have never purchased an '80 clutch from Toyota, it wouldn't be the best biz plan? I haven't seen everything, life would be boring if that were the case? But have worked on ton of cars and IMHO Toyota consistently ships more accurate parts than most. I'm sure they have shipped a few defects, sorry that you received it.

 

[landtank]

I haven't read the early part that huge thread in a long time, IIRC it is is so full of conjecture that has now been proven wrong, that it's bordering on useless. I however did review the first couple of posts.

Your recommending using a dollar store 1" thermometer, 3" away from the thermostat and calling Aisin's calibration inaccurate?

I have sold thousands of those 1" thermometers, well not dollar store, but with some of the biggest names in the tool biz and significantly higher in price. They came in display boxes containing ~12 and ~24 of those in a case. We would open the tops, so they could be seen and calling the accuracy "about" would be generous, they read all over. Have done a bunch of playing with them and the accuracy, repeatability of them is somewhat better than a guess, maybe.

I also started out using the pan/liquid/thermo (digital) method, saw some inconsistency. Stepped up to a better/quicker acting thermistor setup and found that the clutch worked as a big heat sink, the liquid in the pan measured different temps depending on where the sensor was placed. Went to air heating with the sensor directly in contact with the thermostat, measuring the actual spring temperature. Using this method, the clutches that I have done have been pretty darn consistant.



Agree, seeing how I have never purchased an '80 clutch from Toyota, it wouldn't be the best biz plan? I haven't seen everything, life would be boring if that were the case? But have worked on ton of cars and IMHO Toyota consistently ships more accurate parts than most. I'm sure they have shipped a few defects, sorry that you received it.

nice retort, but the fact that more than just my clutch wouldn't engage out of the box without advancing the timing still seems to point to a calibration problem at the factory.

And if attacking and making fun of my testing methodology makes you feel good about yourself, go for it. Have a field day with it.

 

[Tools R Us]

Whatever, I can agree to disagree, our experiences, observations differ and leave it at that.

 

[cary]

Just going to throw some wood on the fire. Although not overheating (no days where I have had the truck in more than 90f weather), I noticed that my clutch is no longer roaring on startup. This is a less than three year old blue hub clutch that was temp calibrated, and filled with 6000 cst fluid as of less than 2 years ago. I am guessing either the fluid has sheared or leaked out (don't see any leakage signs).

As has been said before the stock fluid is way to thin and it seems the 6k fluid is also. I am going to order the 10,000 cst and have a go out it.

 

[Tools R Us]

How much fluid did you put in it? A theory or two: Overfilling to reservoir capacity makes for longer lasting fluid, not sheared as often? Thicker fluid lasts longer, the clutch isn't "engaged" as often and for a shorter time, it comes on does the job and turns off?

 

[Buckru]

Just going to throw some wood on the fire. Although not overheating (no days where I have had the truck in more than 90f weather), I noticed that my clutch is no longer roaring on startup. This is a less than three year old blue hub clutch that was temp calibrated, and filled with 6000 cst fluid as of less than 2 years ago. I am guessing either the fluid has sheared or leaked out (don't see any leakage signs).

As has been said before the stock fluid is way to thin and it seems the 6k fluid is also. I am going to order the 10,000 cst and have a go out it.

Cary,

I have 7k in my unmodded clutch at the moment and have seen a slow decline in performane over about 2-2.5 years. I live where it's a bit hotter but my results are similar to yours. Modded clutch or not, the fluid will simply degrade over time. Based on a converesation with Tools, prior to this thread, I picked up some 20k. It's sitting on the bench and goin in this weekend. (thanks again Kevin)


Buck

 

[landtank]

I've been using 10k oil as of last year and have been filling the blues with 35ml of it from a full drain.

It seems like that 35ml is about twice as much as what the factory puts in.