Re: Am I Just Lucky?

[paul.heneghan@bbc.co.uk (Paul Heneghan)]

From: orin@netcom.com (Orin Eman)


>> 1)  To break my crank bolt loose, I used a 2 foot extension on a
>> 1/2" drive breaker bar.

>I did use the 5' pipe to break it loose, though I was pulling upwards
>meaning I would be putting considerably less than my weight on it...

Not necessarily.  I (and most other people) can lift considerably more than 
my weight.  However, I can only push down with my own weight (I can of 
course increase this if I wear a backpack full of stones).  It's worth 
remembering this when trying to loosen a wheel lugbolt by the side of the 
road after some ape has tightened it with an air tool.  Just a pedantic 
point, but I'm feeling pernickity (sp?) today.

>> 2)  My Bentley specifically shows the torque on the crank bolt to be
>> 258 lbs/ft., or 350 n-m.

(For info. only: It's lbs x ft, not lbs/ft, also it's Nm, not nm)

>For the 84-88 5k, the Bentley shows an extension tool (2079?) which is
>approximately 12" long.  The given torque spec was for use with this
>tool only.  Assuming a torque wrench of around 18" length, we calculated
>the torque at the bolt to be 400 - 500 ft-lb!

258 x (18 +12)/18 = 430.

>> 3)  I hear a lot of discussion about using Loctite on the crank
>> bolt when re-installing it.

>The older Bentleys talk about a locking compound, hence the confusion.
>I hadn't heard the Anti-corrosion discussion when I did mine, so I
>used loctite.

I had one come loose on me (I had the belt replaced by a workshop a year 
previously). The car lost a LOT of power as the valves became very retarded. 
 It made a complete mess of the crank pulley and also did a slight bit of 
damage to the crank.

Next time I do the job (I'm not going to trust the garage - I think either 
they didn't use loctite or else used the wrong torque) I'm going to torque 
it to about 500 lbs.  That's the equivalent of me (about 200lbs) standing on 
a extension 2.5ft long.  That should hold it.

Paul
paul.heneghan@bbc.co.uk
1984 Audi 80 quattro
1989 Audi 100 Avant