Meyle fan clutch

[shogun]

was the engine at operating temperature?

If the fan clutch operation is normal, when first starting the car, the fan clutch should “clutch up” and an increase in noise and airflow should be obvious. After about 60-90 seconds, the fan will un-clutch and the noise and airflow will drop. The fan will continue to turn but at a much reduced speed. As the engine warms and the thermostat opens to regulate the temperature, the air thru the radiator gets hotter and the clutch will sense this, thereby increasing the speed of the fan to maintain a normal operating temperature.

Testing the fan clutch:

If you have reason to suspect that a fan clutch is defective, here is the recommended procedure to verify the condition of the fan clutch.

1. Start the car (cold) with the hood open and note if the fan is turning, increase the engine RPM and note if the fan turns faster and the noise increases, if it does, first good indication, if it does not increase speed/noise, clutch is bad and needs to be replaced. (Remember, this must be tested after the car has been off for and extended period, over night etc.)

2. Leave engine running and note if the fan starts to slow down after 2-5 minutes, speed/noise should diminish and even raising the RPM, the fan should not make as much noise as when first starting, if it does slow, this is the second good indication. If speed/noise does not decrease, clutch may be “frozen” and should be replaced.

3. Leave the engine idle and watch the temperature indicator. When normal operating temperature has been reached, some increase in fan speed/noise should be noted, in particular when the RPM is increased. If temperature is fairly stable and the fan noise/speed increases or cycles, third good indication. If temperature indication continues to increase, with no increase in fan noise/speed, clutch is defective and should be replaced.

4. After the engine is at normal operating temperature or above, is the only time that the “rolled up newspaper” test that many people talk about should be performed! Take some newspaper and roll it up into a long narrow tube. Be carefull, keep hands and fingers away from the fan while performing this test! With the engine at full operating temperature and idling, take the rolled up paper and insert it on the back side of the fan and try to reach the hub of the fan avoiding the blades until close to the hub. Push the rolled paper at the fan increasing the friction to the hub area of the fan. If the fan can not be stopped easily this is the fourth good indication, if it can be stopped the clutch is defective and should be replaced. Again, this test can only be performed when the engine is at or above full operating temperature.

[BennyM]

I have read this, but I havne't done the newspaper test. The fan is really loud at startup and then it does get quieter when the engine reaches operating temp. While bleeding the coolant system yesterday, I could definitely tell when it was engaging and dis-engaging, and it was irrespective of engine speed, but it never gets as slow or quiet as I would expect. So, I don't think it's forzen in the clutched position, it just doesn't seem to be un-clutching completely. The outside air temp is actually really cold right now (40-50* F), so I don't need it to spin at all, but alas it is. I wonder if I messed it up by forgetting to store it upright for two days after it was delivered. No oil leaked out or anything, which I understand is the concern when storing it flat.

[Tiger]

I would contact your seller... I believe BMA regarding this. Doesn't sound normal to me... I had a fan clutch like that and it died very soon afterward... it is just so freaking loud and partically locked.

[shogun]

or just normal as he said:

it's been so long since I've had a functioning fan clutch, that I forgot how strong it is

better a good functioning one than a bad one.
I have repaired meanwhile more than 10 visco clutches by injecting oil. And depending on my buddies request I added as much oil as they wanted, some wanted to have a stronger fan clutch. Trial and error was the case.
as I am lazy, I drilled a hole like this
ML 320 Fan Clutch Repair - Benzworld.org - Mercedes-Benz Discussion Forum

And I thought that was my "patented invention" to drill a hole

[genphreak]

I like the idea of refilling/topping up the fan clutch. Is the reason they go defective that:

1. the factory oil spins out due to a worn bearing, or
2. if it gradually just exits due to time/use/ambient temperatures?

... and wonder where else that oil can be found!

- 10,000 CSt oil- silicone oil
- Toyota part XXXX-TBA

[shogun]

over the years tiny amounts are leaking. That is why the fan clutch manufacturers also have special instructions how to store new fan clutches = flat and the opening in front on the top.

If you refill small amounts, the fan clutch will have another life. My buddy uses on his Alpina B12 E32 always such refilled fan clutches, he says, he can fill up the amount as he likes it for more cooling speed.

quote

TOYOTA Silicone Oil refill the fan clutch*.



*The Toyota dealer says there are three types of viscous fan clutch silicone. They are rated at 3000 CST, 6000 CST, and 10,000 CST. (the higher the Cst rating, the higher the viscosity (THICKER fluid) All priced the same. The only reference to this stuff that the Toyota parts jock could find, was a TSB from 1975 specifying the fill procedure for the clutches of that year, The 3,000 Cst. was for all Toyotas except for the Celica (the only “sporty” car they offered in 1975), which got 6,000 Cst. The 10,000 Cst. was not assigned an application by the TSB. He guessed maybe the Land Cruiser but didn't really know. Anyway, the part numbers are 08816-03001, 08816-06001, and 08816-10001, respectively. (Each bottle is 18mL; you will probably need 2-3 bottles depending on your specific fan clutch)
unquote


so just buy some silicone oil with the required cst and make some tests. Amount/volume of injected oil is just by experience.

Here are the instructions:

[shogun]

another idea, older Mercedes Benz models had them OEM installed

modifying torque converter with drain plug

here made on a TC on a 4HP22
shogun WandlerAblassschraube, Bilder-Speicher.de

Made by Dansker, a member on the German 7-forum and independent repair shop owner and specialized on older BMW.

Good idea, still needs to be long time tested.

He does not like the mess to get the air out of the TC with compressed air, so he welded on a drain nut with plug.
His comment:

Den mit Oel gefuellten Wandler in einem Schraubstock legen, und an der tiefsten Stelle, mittig neben der Schweissnaht, ein Loch von 5mm Bohren. Natuerlich laeuft dann das Oel aus, aber es nimmt dann gleich eventuelle Bohrspaene mit. Als naechstes, eine 6mm Schraube (Am besten mit einer Spitze) in eine 6mm Mutter hineindrehen, so das diese dann buendig auf der beigebrachten Bohrung auf dem Wandler zu liegen kommt. Nun die Mutter auf den Wandler anschweissen. Anschließend mit einem 6mm Gewindebohrer, die Bohrung im Wandler, mit einem Gewinde versehen. Danach mit einem Winkelfraeser die Mutter konisch auffraesen, dass sich eine 6mm Flachkopf Senkschraube, mit einer 6mm Kupferdichtung, uebergangslos in die Mutter Schrauben lässt.
Achtung Aufpassen!!:
Am besten, mit einer Bohrmaschine mit Anschlag Arbeiten! Nicht tiefer wie 7mm mit dem Bohrer in den Wandler Bohren, da sonst ein Schaufelrad verletzt werden könnte. Die Ablassschraube darf nicht laenger wie 8mm lang sein, da sie sonst in den Wandler ragen koennte, und die Mechanik blockieren koennte.
Noch etwas: Es muss eine Senkkopfschraube verwendet werden, da zwischen Wandler und Wandlergehaeuse nur 6mm Platz ist. Bei Gebrauch einer 6-Kantschraube, wuerde diese an das Wandlergehaeuse schlagen.


translation by google
The oil-filled TC put in a vice, and at the lowest point, in addition to the center of the weld, drill a hole of 5mm. Of course then ATF runs out/drains, but it will also take metal particles caused by the drilling out of the TC. Next, screw in a 6mm bolt (Preferably with a point) in a 6mm nut so that it then comes to lie flush with the hole on the TC. Now weld the nut onto the TC. Then with 6mm taps, the hole in the converter, provided with a thread. After reaming with a conical Winkelfraeser/angle grinder the nut that a 6mm flat head countersunk screw with a 6mm copper gasket, can be seamlessly integrated into the bolts.
Caution, Be careful!:
At best a drill with a stop works! Not go deeper than the 7mm drill drilling into the converter, otherwise a wing insert could be injured. The drain plug should be no longer as 8mm long, because they block otherwise could extend into the TC.
One more thing: a flat head screw should be used, there is between the TC and TC housing only 6mm space. In use, a 6-head screw, this would damage to the TC housing.

He mentioned that the weight is about 5-10 grams and hopes there will be no unbalance.
Others mentioned the Mercedes Benz has such holes for draining fluid in TCs in the old W124 model. As counter weight they welded on the other side of the TC small metal plates as weight. ads say:"Brand new Auto transmission torque converter drain plug for All Mercedes, gasoline and diesel, from the late 60s up to the late 90s. If you are doing a complete transmission flush you will need to drain the torque converter."
But apparently the MB fans also have their probs, quote
Draining the torque converter
Unlike Chevies, the torque converter on the Benz has a drain plug. But it must be rotated so that it ends up at the bottom.
OK... but how do you rotate the motor? I looked for a bolt on the crank pulley but, short of removing the fan and shroud, it is not accessible. Is there a trick to it? I tried the starter method, but I keep missing the mark. And I felt I was abusing that poor starter. Any ideas, suggestios, recommendation? unquote

Further was mentioned that the TC wall thickness is about 2.5 mm.
I have made some pics some years back when a shop in Yokohama remade my TC, here you can see the innards
http://www.bimmerboard.com/members/h...Convertor1.jpg
http://www.bimmerboard.com/members/h...Convertor2.jpg
http://www.bimmerboard.com/members/h...Convertor3.jpg

[BennyM]

Well, I'm sure a certain amount leaks out over time, but the fan clutch I replaced was completely covered in oil, so I'm thinking some kind of internal seal had also failed over time.