air conditioning renew

so after some considerations finally i have decided that in order to have the necessary gap between radiator and fan i need to go back to the original reibekupplung, AKA the friction clutch with the five blade fan

i have checked all the other posible combinations, and NO the visco with the big nut is NOT thinner tan the other one

the question was why my original friction clutch was dead and not working, well i found that the only faulty part was the friction element, too thin to work properly, so i tried to find one, mission impossible, no way

so i have it recored in new friction pads, just in the moment i did found a NOS replacement, life is funny !



left: NOS replacement
right: my old one recored in new friction pads

 
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Friction wheels

When I worked at the dealer, we use to add shims to the friction discs in order to get them to lock up sooner. I can't remember what the thickness was but it wasn't much. They were small discs made from a hard material, not steel, almost like cermaic but of course not in those days. They were put into the small hole in the center of the friction wheel so they would cause the friction wheel to expand quicker and. therefore lock up the fan quicker. If I really look through my "junk" drawer in my toolbox, I might be able to find a couple. It was sort of a trial and error system but after a bit, we were quite able to get them done fairly quickly.

Thanks, Rick
 
stphers said:
When I worked at the dealer, we use to add shims to the friction discs in order to get them to lock up sooner. I can't remember what the thickness was but it wasn't much. They were small discs made from a hard material, not steel, almost like cermaic but of course not in those days. They were put into the small hole in the center of the friction wheel so they would cause the friction wheel to expand quicker and. therefore lock up the fan quicker. If I really look through my "junk" drawer in my toolbox, I might be able to find a couple. It was sort of a trial and error system but after a bit, we were quite able to get them done fairly quickly.

Thanks, Rick
Click to expand...

hi rick, it seems that your action was trying to elongate the life of the friction element by making the thermo element push forward

it is a good meassure to give an extra duration to the element

my process has been to renew the element to its original thickness, but i will consider your tip for the future

regards
 
you will recall that i made the schematics for gaining some free space for fan relative to triple core radiator,








now this has been applied

here is the solution done, i used the standard conical piece and we removed 5mm from the base to allow the clutch go backwards 5mm



this means 5mm less, so the clutch and fan assembly will go 5mm backwards providing a 5mm bigger gap between fan blades and radiator,...

... but there is one aditional feature, take a look from the top:



yes, the bolt has been changed to a flat allen bolt and submerged into the locking piece, this gains 7mm space compared to the original bolt position, remember that the bolt protrudes from the fan blades into the radiator place, so you do not get much better if you do not make both of these modifications



 
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You may still need a washer of some type in order for the base to only contact the rotating inner bearing of the clutch? Otherwise it may lock in place?
 
results

original system





height: (158mm from table to top) (table level will be the reference point in the engine block )




modified element: a copper 1,5mm washer has been added (there is no real need, but just in case)





meassure now (146 mm between table and top ) top point is now 12mm more away from radiator, but in fact radiator fan wings have moved backwards only 5mm )




 
the impossible

thanks to the generosity of a very generous man,...

parts they are, those ones you never dream you would be able to touch with your fingers ever

parts that my grandfather recalled hearing stories about them to his grandfather

parts that maybe never did exist

parts that Little Fritz, master of fake and lies, included in the drawings that filled the BMW microfiches in the seventies for his own secret joy, or in a disputed contest with Hans for the Price of some "Heffeweissbier"

secluded in the darkness of the belly of the central console, this is one of those parts,...:wink:











it is being cleaned, and still looking for some felt to redo the sealings,...planing to include it in my airconditioning renew

BTW if someone here knows about mold tooling for plastic parts, can probably realice about those negative angles that make the part (even it is a two halves) so complicate to produce
 
@deQuincey : I have disassembled my fan system, and my (quite original) car still has the friction elements. I'd like to check if they need to be resurfaced, just as you did.
Where can I find the dimensions of the lower tolerance of the friction material (or Diameter)?
I've looked into the technical, under Water pump, but all i can find is the spec of 0,9 mm plm 0,2 for the clearance between housing and impeller.


1640008110903.png


I also do not find any value in the tech books:
1640008448901.png


Anybody has a value I could use ?
 
eriknetherlands said:
@deQuincey : I have disassembled my fan system, and my (quite original) car still has the friction elements. I'd like to check if they need to be resurfaced, just as you did.
Where can I find the dimensions of the lower tolerance of the friction material (or Diameter)?
I've looked into the technical, under Water pump, but all i can find is the spec of 0,9 mm plm 0,2 for the clearance between housing and impeller.


View attachment 132641

I also do not find any value in the tech books:
View attachment 132642

Anybody has a value I could use ?
Click to expand...


i replaced the friction material with a 2,7mm thickness pad
 
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