Crank bolt torque for timing belt change (10v)

[Kneale Brownson]

Where does the recommendation for thread lock come from?  I'd think adding
a thread lock compound would make future removal impossible.


At 02:05 PM 12/1/2003 +0000, rob hod wrote:
>  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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