Proper Pulley Torque Question?
 

One more question guys.

I seem to be a little confused as to this, with or without air conditioning torque difference thing.

In Waynes book it states:

Crankshaft pulley bolt (without A/C) 80 Nm. use spring washer.
Crankshaft pulley bolt (with A/C) 170 Nm.

The problem is:
The car, use to be equipped with A/C. But not anymore. (No belt \ No compressor)

The pulley is the same, and I do have a spring washer below the nut.

My interpreted assumption is 80 Nm. As the Service Manual states.

Would this be the correct assumption?
I would hate for the pulley to come loose.:eek:
Thanks,

Mike.

Spitting off a pulley is a very bad thing. That is why we quit using the old style bolt in favor of the new, serrated flange bolt that comes on the later engines.
999 093 005 02 torqued @ 170 nm

http://forums.pelicanparts.com/uploa...1267146613.jpg
http://forums.pelicanparts.com/uploa...1267146757.jpg

Thanks, Henry.

I new you would come to the rescue.

So your saying it should be torqued to the higher number, regardless of which bolt I use?

Also, your highly recommending the later style bolt #999 093 005 02. Just toss the old bolt and washer.

80 Nm is not correct. I had it wrong.

Once Again, I should just order the bolt from you, along with those arms.

Thanks,

Mike.

"So your saying it should be torqued to the higher number, regardless of which bolt I use?"

I don't think this is what he meant, as you'll likely either plastically stretch or twist off a lower strength 8.8 or non-Durlock 12.9 bolt if you torque it to 170 N-m. Only the 999 093 005 02 12.9 strength class Durlock bolt should be torqued to that level.

See:

http://forums.pelicanparts.com/911-engine-rebuilding-forum/163214-crank-pulley-bolt-washer-no-washer.html

Thanks Jim,

I was waiting patiently for more feedback on this question.

Theres no way in heck, I was going to torque that bolt to 170 NM.

Over torqued enough bolts by now to see what could feasibly happen.

I'll just leave it at 80 NM or get the other bolt and go from there.

Appreciate the link.

Mike.

I guess I wasn't as clear as I thought.
Throw away the old bolt and buy the new style bolt. Then torque the new bolt to 170nm.
This is the best option for all engine rebuilds.
Sorry for not being clear before.
cheers

No problem Henry,

Thats why, I held off torquing it,
Kinda figured that, I may have miss interpreted the information you gave to me.

Thanks,

Mike.

Great thread!

Is 170nm the correct factory-spec for the pulley bolt on all air-cooled 911 engines? In particular I am wondering about the correct spec for a 1992 911 turbo (3.3L).

**Update - the factory shop manual for a 1994 911 turbo 3.6 lists the torque spec as 235 Nm (174 ft/lb).

Is this a one-time-use "stretch bolt" or can it be reused?

Does anyone know what year the new serrated bolt was first used by the factory?


Thanks :)

Looks like 1984 from the parts diagrams. Reason I say this is because in '83 it shows the bolt with a washer under it. In '84 it shows just the bolt.