Crank bolt torque for timing belt change (10v)

[Alan Pritchard]

hmm, when I did my cgt I just banged the bolt in, as it was, and using a 3/4
M breaker bar put all my weight on it (150ish pounds). Not a bad guess, that
works out at about the 300 pound foot mark....
Mind you, that's my yardstick for all f***ing tight torque settings.

 -----Original Message-----
From: 	rob hod [mailto:rob3 at hod3.fsnet.co.uk] 
Sent:	01 December 2003 14:05
To:	quattro at audifans.com
Subject:	Re: Crank bolt torque for timing belt change (10v)

  Hi Gang,

    I guess the main requirement is that the bolt provide a good clamping
force for the damper onto the nose of the crank. I don't presume the cast in
key is there for much more than location purposes.

    A while back I got hold of an ex-army torque wrench thats ideal for this
job as it's 5 foot long and rated from 180lb/ft to some crazy figure I don't
even recall. Driveshaft nuts are now literally a pushover.

  However, before I had this I needed to change the belt on my I5 avant as I
bought it with no recent history. I undid the nut using a breaker bar, but
for replacement I had only a wrench that went to 250 lb ft, so I used this
(and the recommended dose of thread lock).

 My theory, which seems to have held true was that the biggest force that
could ever be put on the asembly would be a stall, e.g. rev the engine in
gear and then drop the clutch, and that most problems that people had
experienced were probably due to monkey-boy type scenario's where a
seriously low torque had been used, and maybe no thread lock compound.

Since this car was an auto I figured that a good 250 plus thread lock would
be tight enough to transmit the torque to run camshaft, water pump etc etc,
and that the stall scenario would be unimaginable.

  Over 30,000 miles later it's still fine, now I'm not recommending anyone
follows my example, and I wouldn't even have considered this without it
having an auto trans, but I thought it might illustrate to listers that, as
someone already pointed out,
 a few pound/ft here or there around the 320 mark should be fine. On the
other hand I'm not so sure about jumping up and  down on the end of a 4 foot
bar, especially if like me you're weighing in around the 220lb mark! I mean
doesnt that equate to 880 lb/ft?

  Cheers,

rob

> Message: 10
> Date: Mon, 01 Dec 2003 06:09:39 -0500
> From: Ameer Antar <antar at comcast.net>
> Subject: Re: Crank bolt torque for timing belt change (10v)
> To: quattro at audifans.com
> Message-ID: <20031201110911.D8A694B4BE at audifans.com>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1"
>
> I'm not sure why I bother, but shouldn't the torque actually be a lot more
than that? If you use the tool and you're putting 258 ft-lbs on the
t-wrench, then for simplifiying the numbers you can assume the t-wrench is
exactly 1-foot and you're putting 258 lbs at the end of it. (You could make
the t-wrench 30 inches, but it's the same thing, you just need a different
weight to match the 158 ft-lbs). So then you are also adding another foot of
extension, so the new torque should be something like 258 lbs * 2 ft = 516
ft-lbs. Torque is simply the weight applied to the bar or wrench times the
distance from the bolt center to the point where you apply the weight. I
doubt you'd need to torque it that high to be safe, but it seems like that's
what Audi wanted you to do.
>
> -Ameer
>
> ---Original Message---
> Date: Sun, 30 Nov 2003 12:17:51 -0800
> From: "KUNZ,BOB (HP-Boise,ex1)" <bob.kunz at hp.com>
> Subject: Crank bolt torque for timing belt change (10v)
> To: "'quattro at www.audifans.com'" <quattro at www.audifans.com>
> Message-ID:
> <345D43ADFFFF864298F9ECD6C5D574E803136236 at xboi21.boise.itc.hp.com>
> Content-Type: text/plain
>
> OK, guys. I've looked for the actual torque on this bolt and have found so
> far...
>
>
>
> 330 ft-lbs at the bolt
>
> 450 ft-lbs at the bolt
>
> 400 ft-lbs at the bolt
>
> 258 ft-lbs at the end of the 2079 tool
>
>
>
> Of course Bentley says use the 2079 tool but they don't say how long the
> torque wrench is which is a variable one must know in order to get the
> setting right.
>
>
>
> The center to center length of the 2079 is 12 inches. If the length of the
> torque wrench is "L" and the torque setting on the wrench is "T" then the
> torque delivered to the end of the 2079 tool is: T * ((12+L)/L). This
> assumes the 2079 and torque wrench are in line, otherwise we have to apply
a
> sin function. So I'm missing one more variable, either the actual torque I
> need or the length of the torque wrench that Bentley describes. Picture
> 17-223 in the Bentley shows that clearly the torque wrench is longer than
> the 2079 but then the bar goes outside the picture frame.
>
>
>
> So, anybody have the actual torque for this bolt?
>
>
>
> --bob
>
>
>
> '86 5ks Avant original owner
>
> '02 TTQR
>
>
>
> ------------------------------
>


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