Fan housing stud conversion

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tommu
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Fan housing stud conversion

Post by tommu » Thu Apr 19, 2018 8:33 pm

I am removing the 4 studs that the fan housing hangs on and replacing with bolts. I shall use blue thread lock when I install. Is this generally seen as a ‘bad’ thing to do? I’m planning on fitting AC some time later this year or early next and want to be able to get to the pulley without too much hassle.

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SlowLane
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Re: Fan housing stud conversion

Post by SlowLane » Fri Apr 20, 2018 7:38 am

I'm sure that I saw a thread on the Samba on this very topic fairly recently (ie. within the last year) Can't recall if there was any conclusion to the discussion.
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Amskeptic
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Re: Fan housing stud conversion

Post by Amskeptic » Fri Apr 20, 2018 9:21 am

tommu wrote:
Thu Apr 19, 2018 8:33 pm
I am removing the 4 studs that the fan housing hangs on and replacing with bolts. I shall use blue thread lock when I install. Is this generally seen as a ‘bad’ thing to do? I’m planning on fitting AC some time later this year or early next and want to be able to get to the pulley without too much hassle.
No, you don't want to do that. There is a definite and limited life to any threaded fastener going into a soft material like aluminum. The reason we have studs is to leave the aluminum alone, and just annoy steel nuts on steel studs.

The indexing of the fan housing is a marvel of German precision. There are "lands" for the fan housing to index to, and the studs as installed by the factory are perfectly aligned to those lands, Once you have removed the studs and start chewing in bolts, you are losing the index, which is within about a quarter of a millimeter of the true circle described by the crankshaft.

So what about the air-conditioning pulley? You merely remove the rear tin, the fan, and there is the air-conditioner pulley. That is how you install/replace the belt, too.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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tommu
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Re: Fan housing stud conversion

Post by tommu » Fri Apr 20, 2018 9:24 am

A good point about the pulley. I suppose I was thinking of leaking seals, oil cooler seals etc too. I should have more confidence in my own work!

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Amskeptic
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Re: Fan housing stud conversion

Post by Amskeptic » Sun Apr 22, 2018 2:58 pm

tommu wrote:
Fri Apr 20, 2018 9:24 am
A good point about the pulley. I suppose I was thinking of leaking seals, oil cooler seals etc too. I should have more confidence in my own work!
I just had NaranjaWesty's fan out this morning. I said, I said to myself, I said, "that's a fine indexing of the fan housing."
Then I put in the fan:

Image
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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airkooledchris
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Re: Fan housing stud conversion

Post by airkooledchris » Thu May 23, 2019 12:20 pm

Amskeptic wrote:
Sun Apr 22, 2018 2:58 pm
tommu wrote:
Fri Apr 20, 2018 9:24 am
A good point about the pulley. I suppose I was thinking of leaking seals, oil cooler seals etc too. I should have more confidence in my own work!
I just had NaranjaWesty's fan out this morning. I said, I said to myself, I said, "that's a fine indexing of the fan housing."
Then I put in the fan:

Image


Wait, does that mean you switched to bolts after suggesting not to?

While im sure this will end up in someone's signature line someday : "Those don't look like nuts"
1979 California Transporter

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Amskeptic
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Re: Fan housing stud conversion

Post by Amskeptic » Thu May 23, 2019 8:57 pm

airkooledchris wrote:
Thu May 23, 2019 12:20 pm
Wait, does that mean you switched to bolts after suggesting not to?

While im sure this will end up in someone's signature line someday : "Those don't look like nuts"

No. I think you may be mixed up as to what we were talking about?
The fan bolts thread into steel hub. That is fine.
The fan housing magnesium has to attach to aluminum crankcase. You should not use bolts here, you should have studs that are permanently installed, the you can r&r nuts all day long, steel on steel.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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