Fan clutch solves overheating

[Tools R Us]

sure, here's one before she made me unhook the trailer and repack

That's a mighty fine load you have there!

To make this post on topic, I hope you checked the fan clutch before sending her off? I would hate to see her have problems with that "load" on the trip, that could make the ...

 

[semlin]

so Rick I'm in the middle of your "cook" for this. A couple of data points.

1. my set screws are exactly centred in their slots from the factory. a portion of a hole is open on either side of the slot. The outer adjustment holes are completely closed at room temperature.

2. the oil level is 1mm or less over the lip inside the holes on the drive side. it has been sitting for days so it has completely drained out of the control side.

my fan clutch was nearly new when i pulled it last month. about 3000 miles. it is pristine in and out and no signs of fluid loss.

 

[semlin]

ok cook is done. Two more observations

1. adjusting to 50/50 at 110 f was a very small change. the holes were already roughly 1/3 open and were fully open by 116.

2. my plate is slightly out of alignment. the hole on one side is bigger than the other so i went with minimum 50% open.

3. the adjustment is tricky and the temp fluctuations tough to track. I used a meat thermometer touching the spring. tightening the screw can move the plate and you only have a short time before the water cools. the first time i did it i was at maybe 106 when I got it right, but that meant the thing was fully open at 110.

anyway if this all translates into a 5 degree earlier fan clutch engagement we will see what that does.

 

[Cruiserdrew]

I have followed this thread with great interest. I also have an FJ60 that has a fan clutch that is either fully engaged or off. The temp guage is linear based on my experience before I replaced the radiator and fan clutch. The motor stays cool, even at stoplights after freeway exits, where it used to heat up when the old fan clutch was bad. The old clutch was renewed when I added new silicone oil, but then I changed it anyway.

The fan clutch does not cause a "stepped" heat profile IN THE MOTOR. It comes on, blows a bunch of air, and goes off. The temp guage never budges. I'm thinking it does a good job. If anything, it errs on the side of blowing too much air. I'm wondering if a better solution for the 80 series might be rehabbing an old style 80 fan clutch with new high viscosity fluid? I don't really care about small changes in fuel economy and care far more about decreasing the chances of an over heat.

So what do you think? I have 102k on my 80 and an original fan clutch. I also have a spare good old style fan clutch I got from Clownmidget. I was going to buy a new fan clutch from Cruiserdan. Instead should I get some new fluid from Dan, and redo Clownmidget's fan clutch? Should I go blue? No way in heck am I going to run a Hayden/Imperial/Autozone/Crapola clutch. Electrics are out of the question.

Lots of good data here. Keep it coming.

 

[semlin]

well the reason i can mod the new blue clutch at my leisure is that i put the old original back in because it did a better job.

 

[landtank]

WHat I've done, which might not be clear, is to leave the pan with water, clutch and thermometer on the stove burner during the cool down. But I have an electric stove so that burner takes a while to cool off which gives you a nice long time to make the adjustment once you hit 110*. If you have a gas range than try using some heavy cookware like cast iron.

From your description of how your truck was running Semlin, I bet that 5* might make the difference you are looking for.

 

[landtank]

As far as the oil level, I do have ics but not the means right now to post them. I'll try to describe where I filled to.

Looking at the drive side of the clutch while it's sitting on the hub you'll see the large shearing disk. Within that disk there are 4 holes. What I did was to fill that side of the clutch up to the bottom of that disk. I looked into those holes and saw a rectangular notch in the outer rim and watched for the oil level to come up to the underside of the disk.

I'll get pics as soon as I can.

 

[semlin]

yup left it in the pan on the stove here as well but we've got a gas cooker here so I didn't get the benefit of a slow cooling element. maybe a cast iron pan would be better for this if you are using gas.

as for oil level, inside the 4 holes you mention in the drive clutch is a prominent shelf or ledge on the outside. The oil in mine was just swimming over that shelf about 1mm. i can't take photos because the wife took the camera, but on the bright side i did get to cook a fan clutch on the stove using a decent thick bottomed pan instead of having to rig the coleman in the backyard with the walmart camping pots which would be my only option if she were here

 

[cary]

I'm going to throw another observation and thought in the mix. As I have previously posted, in the past several weeks, I have replaced the clutch on my 1996 (blue hub) and the radiator (early brass/copper radiator). After spending some time driving the truck in hot weather I think we may be underestimating the stock blue hub fan clutch. Here is what I observed yesterday in 100f weather:

1) Idling for 15 minutes while I had to go into a fast food restruant with my wife and son in the truck (not so fast). A/C running on high, truck had just been driven for 20+ minutes and come off the freeway. Truck never went over 210f and when I started to drive, you could hear the fan running (not a huge roar) and the truck cooled down to 190f in less than 2 minutes.

2) I was driving my son around trying to get him to sleep. There is a 500 foot verticle climb near my house, about 1 mile long with long sections of 20% grades. The majority of the climb is between 1st and second gear, you run up in first, it shifts to second, and the speed drops back off. Pulling up this, I was able to get the temperature up to 210f, once it got to this point, I heard it, the clutch fully locked up and there was a loud roar as it shifted to first and the fan moved a lot of air.

I have to wonder if partially clogged radiators are the cause of some people's fan clutches not working as soon as they should. If the radiator is partially plugged, you will have less heat transfer through the radiator, hence less hot air blowing on the fan clutch so it doesn't lock up as soon. In my case, I am not getting over 210f, well within the limit of prudent operating temps.

 

[semlin]

Cary,

If you can feel the new fan clutch kick in full bore at just past 210 then that explains a lot and this mod will likely work perfectly for me. I have not exceeded 210 by much since I got the RT gauge and never heard/seen full fan clutch engagement with the new fan clutch. My personal pref would be to have the fan clutch come in full at between 200 and 205.

 

[landtank]

If you are able to open one up, Verify the adjustment and oil level, you could then rule out the clutch and look somewhere else. This takes alot of guess work out of troubleshooting.

Cary, I wouldn't care for my truck to run as hot as your's, but that's me. In 100*F weather and idling I'm at 180*, as best as I can tell.

 

[landtank]

Just as an update, I finally went and gassed the truck up. Besides driving down to the Cape I've also run some local errands before refueling so the number isn't 100% but close enough I think.

I averaged 12.1 MPG on that tank with my clutch adjusted. I'll know better when I get some miles under my belt without towing the trailer.

I also took off the clutch and advanced it some. My thinking is that it will either help the slight increase in highway temps on the way home or not, which would indicate needing thicker oil.

 

[Peyoteboy]

help!!

Sorry, I will repost. I thought i might have found something here and then proceeded to ramble.

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Ok, i read all 7 pages of this post and understood some of it I am suffereing from a heating problem that just about has my wife demanding the sale of my truck. a rundown of the heating fix attempts is as follows:

Truck overheated about 3 years ago and blew a head gasket. Had the head surfaced, gasket replaced and remounted. Still had heating issues, so i replaced the T-stat, radiator and cap. Seemed to work ok for a while, but then summer hit bad (central Texas, 100+ temps). Replaced the fan clutch with an aftermarket from autozone that only says "Torqflo" on the unit. This seemed to do ok, but fall also came along about this time. So i nurse the truck around for a year with no issues but also no AC. I get the AC going again, and temps rise now whenever i am using it, or when i run for more than 5-7 mins at speeds below 45 mph. I replace the water pump to no effect. I take it to a mechanic and they say i have a bad fan clutch and replace it. This also does not fix the issue so they replace the t-stat free, because i had an autozone one of those also.

Now i have 3 fan clutches, 1 in the truck and two in the garage. Two of them toyota parts. I have a OEM tstat. I have a new water pump. I have a 2 year old radiator and cap, and i have a truck that still overheats. I do have 223k on the motor, but the mechanic, who works mostly on cruisers, says the engine seems to run solid.

Is there something im missing thats obvious? Do i need to modify the fan clutch per the thread? Any help would be greatly appreciated.

 

[semlin]

peyoteboy your problems demands a whole new thread rather than hi-jacking this one. repost what you just typed and I and others will respond.

 

[wfd175]

I changed my fan clutch (OEM Toyota Blue) last night because I noticed in town driving the a/c became a little warmer, and there was oil slung out on the blades from the old clutch. It took only 20 minutes, removed 4 bolts, carefully pulled out, replaced clutch and carefully put back in.

The official temp (in St. L) last night at 9 pm was 97 degrees, with a heat index of 114. The a/c did keep up better, and the temp gauge moved from dead center to tipping down, (during in town driving). Also after the test drive last night, I raised the hood and the engine seemed not to be radiating so much heat as before. On the highway everything was always cool and dead center on the temp gauge.

I think the PM was worth it.

 

[landtank]

WFD175, I'd like to get my hands on your old clutch if I read it correctly that you removed a BLUE clutch.

 

[landtank]

Done!!!!!!!!!

Todays drive home from The cape was absolutely perfect as far as truck temps are considered.

The ambient temp was 90* and the truck performed great.

Most of the drive the needle was at normal and would only rise slightly on pulling a grade with the TC unlocked. On those occasions where a downshift was needed the needle actually dropped some and the previous situation where I had a temp spike from the upshift at the top of the climb has dissappeared.

As I just tweeked the control plate last time I don't actually know where it is but will post that in a new thread outlining the complete proceedure of what I've done.

At this point I've gone as far aas I can on my own and will need data from other's to refine this for a better across the board ajustment for multiple trucks.

 

[Bryan062087]

landtank, you still have the hayden clutch in, correct?

 

[semlin]

no, he has an adjusted oem blue clutch with oil added. that fanclutch has internal adjustment screws that allow you to vary the temperature at which oil circulates into the clutch and locks up the fan. He originally varied it to open 10 degrees sooner than stock but has now bumped it a further eyeballed amount.

Rick, how was your mileage? I get my truck back tonight and should have data for you tomorrow. If mileage suffers I am thinking of having both a winter and a summer/towing/mountains clutch.

 

[landtank]

Just got back from filling up the truck, 12.65 MPG on the home trip.

This might be placebo but the truck seems to drive much nicer than before with the trailer in tow. I downshifted into 3rd maybe 3 times and easily maintained 60MPH during the climbs and 70 MPH on the flats. That wasn't the case on the drive down to the Cape last week.

I'm thinking that maybe there is a small snowball effect going on. As the engine begins to run hot it leans out a little which causes the engine to run a little hotter and so on. Any thoughts?

I'll get the clutch pulled later on tonight when the truck cools down and post up the proceedure tomorrow. My wife was kind enough to point out that a stove isn't needed, hot water from the tap is usually 115-120*, she's a school teacher and knows the regs for this kind of stuff.