after 22 years I changed 1st time my fan clutch

[shogun]

While driving today to our wrenching meet to make a headliner on an E32 750 Alpina B12 I had heavy traffic jam, instead of the usual 1 hour it took me 3 hours. Noticed that while in stop and go the needle went up on the coolant gauge and then down again when driving with normal speed on the Highway, so a clear sign that the fan clutch was on the way out. Instead of the usual 83 degree C it showed somewhere around 106 degree C = 223 degree F
http://www.nmia.com/~dgnrg/tempgage.htm
As I had still some new fan clutches on stock in our place, we changed it immy after arrival and testing the fan clutch. Out came a Behr fan clutch from 1988, I have to admit that shows quality. 22 years is indeed a very reliable fan clutch.
Now the gauge shows less than 83 degree C = left of the 12 o'clock a bit with the new fan clutch.

I found in the new fan clutch box (imported from a German online shop) an interesting instruction. The box showed an arrow how to store the box = the fan clutch horizontal in a flat carton box, and the opening where the bi metal is should be of course on top so that no fluid can leak during storage.

Further it said:
before installing the fan clutch keep it stored for 24 hours vertical. Then turn the fan clutch by hand 5 times before installing it.

The old one I will refil and test again, just to see how much longer it will run, like shown here by Johan
http://bmwe32.masscom.net/johan/fan_clutch/fan_clutch.html

That shows to me that a visco fan clutch is very reliable. I have my doubts that an electric fan would last 22 years too.

[Kibokojoe]

Go figure I have kept everything I have ever taken off the 5 except for this part. Dang

[shogun]

thanks Joe for this info you sent me:

Based on the following I found on the web...I am going to say that the silicone oil in the clutch is a 3000 CST

"*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)"


Here some cut off pics
http://www.bimmerboard.com/forums/posts/461360/
http://www.ms-motor-service.de/ximages/1385172_flpinr14lu.pdf
http://www.roststopp.de/strichacht/daten/MB-SA-Viskoluefterkupplung-1968.pdf

[Kibokojoe]

Heres an article where they used the 10,000 CST (08816-10001) but it was on a Overlander 4 wheel drive

http://tinyurl.com/y9vee2c

[bmwrp8]

2 years ago my old fan clutch failed. drilled a little hole filled it with new silicon oil and just closed the hole and used it for around 1 year until it broke again. I brought a new one after that:)