Another Fan Conversion Thread

[floridabmx]

Ok, I have a 72 3.0CS with AC. It's the 5 blade original style and the clutch took a dump. So Im looking to update it.

Theres too much info every where for my head to wrap around. Ive searched but I cant figure it out.

So what exactly do I need to update this the easiest way?

Any help is MUCH appreciated.

 

[HB Chris]

There are two viscous clutches each matched to a specific water pump. The earlier clutch has the typical four small bolts, the newer style which needs the newer pump has a single large bolt behind the clutch, this is called a spin-on clutch.

 

[floridabmx]

There are two viscous clutches each matched to a specific water pump. The earlier clutch has the typical four small bolts, the newer style which needs the newer pump has a single large bolt behind the clutch, this is called a spin-on clutch.

So either will work for my car?

 

[HB Chris]

Depends which pump you have. Buy the same clutch that you have now (they are expensive!).

 

[Markos]

So either will work for my car?

I think that really depends on whether you want to spin a few bolts or drain a bunch of coolant.

 

[floridabmx]

I think that really depends on whether you want to spin a few bolts or drain a bunch of coolant.

Radiator is already out. It's so tight I don't see how it'd be possible to remove the fan without taking the radiator out anyhow.

 

[Markos]

Radiator is already out. It's so tight I don't see how it'd be possible to remove the fan without taking the radiator out anyhow.

Hmm come to think of it my radiator was out when I pulled my fan...

 

[rsporsche]

i took a fan off of an e12 that used 4 allen head machine bolts with the radiator in the car ... we cut off the end of an allen wrench with a dremel tool and was able to get it in there to take the fan off and replace the water pump and put the fan back on. it wasn't fun, but we got it done without pulling the radiator in my friend's driveway. and YES, i still have that allen wrench.

 

[Roger S]

Try this tool for easier removal. Seems corny but was a life saver this past weekend when I installed and pulled the fan and pulley a few times. I tried to attach the link but it keeps resetting. Amazon seems to have it for the cheapest price; search for BMW 32mm Fan Clutch Water Pump Nut removal tool.

Just struggled through the same fact finding and installation scenario. Had the e9 water pump installed years ago to use the stock fan on my 3.5 swap toward a more original appearance. Unfortunately, I only found two viscous clutch fans, no stock 9 fan, and no pulleys for either application.

I got the square "double" pulley for the stock application in error (but right for my pump style) because I was not aware of the rectangular "single" pulley pattern. Fortunately, Carl bailed me out and sold me an early model single pulley (and TA). Buying another pump was the most cost effective and quickest route for the better performing option.

I'm now using the single large bolt or spin on clutch that Chris referenced.

*If anyone reading this has an original AC bracket or one from an 83-88 e28 they want to part with, please PM me. It's part of car lowering strategy and something else I've misplaced/lost. Thanks in advance.

 

[rsporsche]

when i changed one on my e28 533i, 15 years ago, i used a bicycle crank wrench - very thin, strong and long enough. might not be as cheap as what amazon has ... but back then it was the best option ... especially if you have friends who are serious bike guys.

 

[Roger S]

when i changed one on my e28 533i, 15 years ago, i used a bicycle crank wrench - very thin, strong and long enough. might not be as cheap as what amazon has ... but back then it was the best option ... especially if you have friends who are serious bike guys.

Found a cheaper one on eBay and hoping the link works from my phone...

https://www.ebay.com/i/122227699347?chn=ps&dispItem=1&ul_ref=http%3A%2F%2Frover.ebay.com%2Frover%2F1%2F711-117182-37290-0%2F2%3Fmpre%3Dhttps%253A%252F%252Fwww.ebay.com%252Fi%252F122227699347%253Fchn%253Dps%2526dispItem%253D1%26itemid%3D122227699347%26targetid%3D364127856121%26device%3Dm%26adtype%3Dpla%26googleloc%3D1023039%26poi%3D%26campaignid%3D936424496%26adgroupid%3D44875990057%26rlsatarget%3Dpla-364127856121%26abcId%3D1129646%26merchantid%3D113781723%26gclid%3DEAIaIQobChMIueH9-qnE1gIVybjACh0hbwWDEAQYAiABEgKfbfD_BwE%26srcrot%3D711-117182-37290-0%26rvr_id%3D1320600903636

 

[Stevehose]

Hmm i bought a set from UUC and it seems i overpayed. Well maybe not as i bought the single wrench and sent me both. Nice quality though as I believe they make their own.

 

[Ohmess]

I have the four bolt clutch and if I had it to do over again, I would change to the later spin-on clutch. How old is your water pump? Given that you already have the radiator out of the car, consider buying a new water pump and changing to the best fan/clutch alternative.

 

[nashvillecat]

Despite what you might consider to be too much information, I would consider rereading some of the threads on cooling fans and clutches found on this forum and elsewhere.

The so-called one-bolt spin on fan clutch is probably the most popular choice, but consider that there were also a few fan variants that bolted to the viscous clutch. All of the variants have worked well for me, although the thin, more-flexible blades found on the later models seem to move more air than their predecessors. If you are still unclear about the different pumps and clutches and fans, it might be prudent to acquire all three items as a complete assembly. If your cooling system is clean, i.e., well maintained and free-flowing, any version of the viscous fan clutch should be adequate for most needs. Consider that the original five blade assembly served well for decades.

Newer style fan

Older style fan

Note three rather than four fasteners that attach fan to fan clutch.

Also available in red.

With enough duct work, a cooling fan is probably surplusage. More important to have the vehicle number properly illuminated.

 

[floridabmx]

Despite what you might consider to be too much information, I would consider rereading some of the threads on cooling fans and clutches found on this forum and elsewhere.

The so-called one-bolt spin on fan clutch is probably the most popular choice, but consider that there were also a few fan variants that bolted to the viscous clutch. All of the variants have worked well for me, although the thin, more-flexible blades found on the later models seem to move more air than their predecessors. If you are still unclear about the different pumps and clutches and fans, it might be prudent to acquire all three items as a complete assembly. If your cooling system is clean, i.e., well maintained and free-flowing, any version of the viscous fan clutch should be adequate for most needs. Consider that the original five blade assembly served well for decades.

The photos help tremendously. I think my ignorance of the parts is what stopped me from understanding. Thanks a bunch for your time.

 

[floridabmx]

Depends which pump you have. Buy the same clutch that you have now (they are expensive!).

I looked for a replacement clutch for what I have now. Couldnt seem to find it.

 

[Honolulu]

I changed the fan clutch (spin-0n) on my '83 533i once. It was seized REALLY BADLY. I ended up taking off the water pump with fan attached, then destroyed the water pump trying to keep it from spinning so I could unscrew the clutch. Ended up taking the mangled mess to a friendly indie. He put it in his 8" vise and slugged the crank down with all he had - and he was a large person. Then he put a craftsman 32mm wrench on the nut, picked up a sledge and said "stand back". He swung for the fences and on about the third slam, the clutch let loose.

So what? The moral of the story is to keep some anti-seize on the spin-on threads.

I use a bicycle wrench (from a bicycle store, natch) since it's a game I very seldom play. Put the wrench on, sticking straight up, remind self that it's left hand threaded, and whack it several times with a piece of 2x4. Works, as long as the anti-seize is doing its job. Some thoughtfully placed rags help when it lets go.

As for preference between the various styles, you'll have to do what fits, and there can be variances in the relative fore-and-aft positions of the radiator and engine. Some small movement may be available by shifting the entire motor/trans assembly back on the mounts.

Hey, check out the door window misalignment in the Calder replicar...