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Engine Specific Info and Questions => IDI Engine => Topic started by: BP10000 on September 09, 2009, 10:50:23 am

Title: Clutch-Crankshaft Bolts (AAZ)
Post by: BP10000 on September 09, 2009, 10:50:23 am
What is the proper torque for these? The 6 M12 bolts holding the pressure plate to the output flange on the crankshaft.

My haynes (I know...) manual says 44lb-ft +90deg, which seems like an awful lot. I read 22lb-ft in a post on this forum.
If it is the higher figure, should I be replacing the bolts?

I am transferring a used sachs clutch from my blown engine to my replacement one.

Also, would this clutch likely contain asbestos? I'm not blowing the dust around anyway, but it would be nice to know.
Title: Re: Clutch-Crankshaft Bolts (AAZ)
Post by: rallydiesel on September 09, 2009, 10:57:03 am
Those bolts always need to be replaced. All stretch bolts need to be replaced since they deform on the first use and weaken if stretched again. It's 22 ft lbs plus 90 degrees for the 1.6 so the AAZ would probably be the same. Also, they must have threadlock compound on them.
Title: Re: Clutch-Crankshaft Bolts (AAZ)
Post by: Turbinepowered on September 09, 2009, 01:24:01 pm
According to the Mk3 Bentley I have, the tightening torque for the six bolts on an AAZ is 44 ft-lbs plus a 90* turn.
Title: Re: Clutch-Crankshaft Bolts (AAZ)
Post by: burn_your_money on September 09, 2009, 04:14:17 pm
I read 22lb-ft in a post on this forum.


That would either be in reference to the bolts that hold the flywheel to the pressure plate, or it's a mistake. It most certainly is the 44 + 1/4 and they are definitely one time use bolts. Although I do reuse them and I even install them with an impact gun :o That's the midnight I-have-to-have-this-thing-running-in-the-morning mechanic coming out though. If you have the time, do it right
Title: Re: Clutch-Crankshaft Bolts (AAZ)
Post by: rallydiesel on September 09, 2009, 05:32:47 pm
I read 22lb-ft in a post on this forum.


That would either be in reference to the bolts that hold the flywheel to the pressure plate, or it's a mistake. It most certainly is the 44 + 1/4 and they are definitely one time use bolts. Although I do reuse them and I even install them with an impact gun :o That's the midnight I-have-to-have-this-thing-running-in-the-morning mechanic coming out though. If you have the time, do it right

Tyler, you made me check my Bentley twice!  ;) For the 1.6, it is indeed 22 ft lbs plus a quarter turn.
Title: Re: Clutch-Crankshaft Bolts (AAZ)
Post by: BP10000 on September 09, 2009, 07:22:37 pm
ok, where do I get new 12.9 grade bolts? Facca fasteners tried to sell me 8.8 like I wasn't paying attention. I figure this is a case where it makes a difference.
Title: Re: Clutch-Crankshaft Bolts (AAZ)
Post by: Syncroincity on September 09, 2009, 07:40:50 pm
Facca da customer before-a he find out ::)
Title: Re: Clutch-Crankshaft Bolts (AAZ)
Post by: theman53 on September 09, 2009, 07:47:48 pm
I will send a pm. I can get ANY bolt...some of the weirder ones you may have to pay for. Metric 12.9 are some of my better sellers. Just call me when I send you my phone #. Thanks Lucas ><>
Title: Re: Clutch-Crankshaft Bolts (AAZ)
Post by: burn_your_money on September 10, 2009, 04:49:54 am
That would either be in reference to the bolts that hold the flywheel to the pressure plate, or it's a mistake. It most certainly is the 44 + 1/4 and they are definitely one time use bolts. Although I do reuse them and I even install them with an impact gun :o That's the midnight I-have-to-have-this-thing-running-in-the-morning mechanic coming out though. If you have the time, do it right

Tyler, you made me check my Bentley twice!  ;) For the 1.6, it is indeed 22 ft lbs plus a quarter turn.
[/quote]

Well that's kind of strange. Thanks for the correction. Any idea why it would be different?
Title: Re: Clutch-Crankshaft Bolts (AAZ)
Post by: lord_verminaard on September 10, 2009, 06:51:35 am
That's weird.  I'm gonna check mine when I get home.  Having just done this I could have sworn it was more than that.  I think the flywheel to pressure plate bolts, (the really small 12-point ones) were something like 22 but I thought the bigger ones to the crank were more.

These are stretch bolts, so you cannot use normal grade 12.9 in this application, you have to use the VW stuff.  German Auto Parts sells a clutch install kit that comes with new crank/pp bolts, and flywheel/pp bolts, along with some other things.

Brendan
Title: Re: Clutch-Crankshaft Bolts (AAZ)
Post by: Turbinepowered on September 10, 2009, 08:56:24 am
According to the Quantum turbodiesel section of that Bentley, 1.6 flywheels get secured with bolts torqued to 55 ft-lbs (nonshouldered) or 74 ft-lbs (shouldered bolts).
Title: Re: Clutch-Crankshaft Bolts (AAZ)
Post by: Rabbit on Roids on September 10, 2009, 09:10:09 am
That's the midnight I-have-to-have-this-thing-running-in-the-morning mechanic coming out though. If you have the time, do it right

LMFAO. i so understand where you are coming from here...
Title: Re: Clutch-Crankshaft Bolts (AAZ)
Post by: rallydiesel on September 10, 2009, 09:14:01 am
According to the Quantum turbodiesel section of that Bentley, 1.6 flywheels get secured with bolts torqued to 55 ft-lbs (nonshouldered) or 74 ft-lbs (shouldered bolts).

Yeah but flywheels bolts and pressure plate bolts are two different things, especially on the ass backwards IDI's.
Title: Re: Clutch-Crankshaft Bolts (AAZ)
Post by: Turbinepowered on September 10, 2009, 09:18:18 am
According to the Quantum turbodiesel section of that Bentley, 1.6 flywheels get secured with bolts torqued to 55 ft-lbs (nonshouldered) or 74 ft-lbs (shouldered bolts).

Yeah but flywheels bolts and pressure plate bolts are two different things, especially on the ass backwards IDI's.

Don't ya mean the ass backward transverse IDIs? My longitudinal diesels all have the flywheel and pressure plate in the right places. :D


Yup. To clarify, that's the values for flywheel-to-crankshaft bolts.
Title: Re: Clutch-Crankshaft Bolts (AAZ)
Post by: BP10000 on September 10, 2009, 10:27:21 am
I thought the pressure plate attached to the crankshaft and the flywheel attached to it.

I tried reusing the bolts but at least one of them gave it up on final torquing (44+1/4), so it's off to the stealership for me. At least they have free cookies.
Title: Re: Clutch-Crankshaft Bolts (AAZ)
Post by: Turbinepowered on September 10, 2009, 12:29:57 pm
I thought the pressure plate attached to the crankshaft and the flywheel attached to it.

I tried reusing the bolts but at least one of them gave it up on final torquing (44+1/4), so it's off to the stealership for me. At least they have free cookies.

On the transverse cars (Golf, Jetta) it does go that way until mid nineties-ish. The longitudinal cars have a more traditional setup where the flywheel attaches to the crankshaft, then the pressure plate bolts onto the flywheel. The transmission input shaft is supported by a bearing inside the crank as well as the bushing where it passes through into the case. The throwout bearing wraps around the input shaft and pushes directly on the pressure plate spring rather than the transverse cars' method of the throwout bushing pushing on a rod traveling through the center of the input shaft and pushing on a plate to disengage the clutch.

This is why the early transverse cars don't need a pilot bearing in the crank, while all the longitudinal cars and the later transverse cars do.