DIY - Fan Clutch Nut Installation

Just replaced my defective "MTC" Fan Blade.

Those of you who have replaced water pump or done the cooling overhaul know it is a PITA to install the Fan Clutch onto the WP Hub: the space is tight, the thin 32-mm wrench does not have much room to move etc and etc. Sometimes it can take up to 15 minutes to thread this stupid 32-mm Nut.

Well, I just came up with this trick that makes the Fan Clutch Nut Install in 10 seconds! It was a breeze!

- Remember that this NUT is reverse thread, so turn it Counter-Clockwise to tighten it.

- Get a short section of a poultry cord (dental floss or shoe lace is also OK)

- Use a small piece of masking tape to tape one end of the cord onto the NUT.

- Wrap the cord around the 32-mm Nut 3-4 times in such a way that when you pull the cord, the NUT turns CCW (Viewed from FRONT of car)....See Picture.

- Apply a bit of grease or antiseize on the 32-mm Nut to make install easy (also making future removal easy).

- Hold the Fan Clutch snugly against the WP Hub, then Pull the cord upward. This will turn the NUT CCW. No need to tighten the nut. Engine rotation will tighten it.

Install takes less than 10 seconds!

HTH.

ingenious! i'll do that next time. gonna put it on as a bookmark!

I don't need this advice, but I like it.

Originally Posted by djfitter

I don't need this advice, but I like it.

My advice is always free...hehe....

slick... i would just put it on when the car is running..... NOT.

Originally Posted by chivas

slick... i would just put it on when the car is running..... NOT.

Heh he heh ehheheeh funny stuff!

Originally Posted by chivas

slick... i would just put it on when the car is running..... NOT.

Buy $1M life insurance before doing that chivas...hehehe...

That's great! Don't pull too hard, you might start it.

If your fan clutch is in proper working order, just spin the blades and the nut tightens 90%. The last 10% i use a 32mm wrench and a rubber mallet.

Originally Posted by bimmerd00d

If your fan clutch is in proper working order, just spin the blades and the nut tightens 90%. The last 10% i use a 32mm wrench and a rubber mallet.

bimmerd00d, that is not the issue: the issue is how to start the first thread of the stupid NUT!!!! Once it starts to catch the 1st thread in, you spin until it stops. The engine rotation will tighten it.

Originally Posted by cn90

bimmerd00d, that is not the issue: the issue is how to start the first thread of the stupid NUT!!!! Once it starts to catch the 1st thread in, you spin until it stops. The engine rotation will tighten it.

OH, yeah that's a pain in the buttocks (forrest gump).

Thanks Cn90--When I was opening the thread ,I started to wonder if it was possible to tie a piece of cord on and make it do the trick--will be useing this in the next couple of weeks.
I was just imagining how difficult putting the fan back on was going to be-no room and all
The fan will sit on the hub I understand and with the rope trick I can see this greatly aiding the rebuild.

Yeah, some people spend up to 30 min to thread the 32-mm nut in, after some "nice" language like "wtf" it will go in. This is because the space is so tight, unless you have small child hands, it is very difficult to catch the 1st thread...Been there done that...

Very clever, but sense my both belts snapped last week and left me stranded on the side of the beach...the easiest way I found to put the fan back on was to hold the fan so that the nut was pushed up against the bolt and have my buddy give the car a real quick crank(not start the car) on the ignition.

Another option is to go from the bottom and thread the nut on. The fan shroud has larger gap on the bottom that makes it quite easy to reach your hand up and start the threads.

Would you be offended if I took a life insurance policy on you?

Very clever!

Or you could just give up and weld it on.

good tip- getting the thing started is the hard part, at least for me.

I am getting ready to replace mine this weekend on my 528i and can't thank you enough for the tip before I get started.

Good job.

Great idea!

I didn't know about this wonderful trick until it was too late.

The last thread or two of my water pump shaft is "sharp" to the touch, such that the fan nut is going on crookedly (details here and here).
I'll bet this next question has never been asked on Bimmerfest before ... but I need to know ...

Q: Do you know what the tap size is for the water pump shaft threads?

BTW: Below is a pictorial DIY of cn90's suggested method. It failed for me, but, only because I had already stripped the last thread or two of the water pump shaft NOT using this method!

That's awesome. I just did the full cooling overhaul and they say the first step
and the last step (dealing with that hex nut) are the hardest. They turned out
to be the easiet thanks to that trick. I used kite string and duct tape.
*
now I just gotta deal with air in the system. Everytime no matter what I try
I always get it.

I was amazed I guess or maybe just lucky but I was able to just grip the fan on both side and spin it right on the nut to start it*...then I just spun the fan to tighten it as much as possible and threw the 1 1/4" wrench on it to tighten it a tad more. Just let the engine to the rest over time.

* - Okay, I tried doing it from above for a few mins...then below for a few mins...then I was going to try the string trick and decided to try it from above again and son of a gun, spun the sucker right on. Lucky me.