Flywheel bolt torque?

[harryrcb]

Originally Posted by JFP in PA

There are not two procedures, there are two stages; for the flywheel bolts (new only, do not reuse), torque to 19 ft lb, then tighten another 120 degrees of rotation to gain the correct bolt stretch. For the pressure plate, torque to 17 ft lb.

Hi JFP, just a quick question, I know the bentley book says 120 but in my Porsche manual it says 18 and 90 - why the difference and which is right?

[JFP in PA]

I just took a moment to look it up in my OEM manual set, and in Group 3, 30-1, page five under torque specs for dual mass flywheel, it says “25 Nm (19 Ft. Lb) plus 120 degree tightening angle”. As we kept this set current with all updates, I believe this is the most current info; yours may be from an earlier text.

[Gilles]

JFP,
Out of curiosity, if you use Locktite red on these bolts (4 insurance) before applying torque, would the real torque values be too different? Since you are supposed to oil the threads..

Originally Posted by JFP in PA

I just took a moment to look it up in my OEM manual set, and in Group 3, 30-1, page five under torque specs for dual mass flywheel, it says “25 Nm (19 Ft. Lb) plus 120 degree tightening angle”. As we kept this set current with all updates, I believe this is the most current info; yours may be from an earlier text.

[JFP in PA]

You should be using some type of lubricant on any torqued fastener, be it anti seize, oil, or thread locker. I’m sure there are small differences between each, but that there would also be a larger variance if the fasteners were assembled dry. I think ARP did a “white paper” on this subject several years ago, so you may want to check their site for more info.

In any case, by far the most accurate way to assemble with fasteners is to measure bolt stretch rather than torque. This is one of the reasons why Porsche uses “micro encapsulated” single use fasteners in several locations (like the flywheel), and uses torque specs followed by “tightening angles”, which are attempting to take into account the stretch factor………

[spendy]

Originally Posted by JFP in PA

This is one of the reasons why Porsche uses “micro encapsulated” single use fasteners in several locations (like the flywheel),

Is this true with all engines? The OEM FW bolts I ordered for my 2.5 are not micro encapsulated. 999 073 092 02 Did I get the wrong ones?

thanks

[PorscheFan5]

Thanks all.

[JFP in PA]

Originally Posted by spendy

Is this true with all engines? The OEM FW bolts I ordered for my 2.5 are not micro encapsulated. 999 073 092 02 Did I get the wrong ones?

thanks

Not all engine's use them, but the M96/97 did. The bolts should have a blue-green area on the treads that is the micro encapsulated thread locker. If they do not, just use Loctite and you will be fine.

[harryrcb]

Originally Posted by JFP in PA

I just took a moment to look it up in my OEM manual set, and in Group 3, 30-1, page five under torque specs for dual mass flywheel, it says “25 Nm (19 Ft. Lb) plus 120 degree tightening angle”. As we kept this set current with all updates, I believe this is the most current info; yours may be from an earlier text.

Thanks JFP , I must not have the updates, do you know where I can get those?

[JFP in PA]

Originally Posted by harryrcb

Thanks JFP , I must not have the updates, do you know where I can get those?

You can no longer get them; they went out of print when Porsche stopped printing the manual sets and switched to an electronic subscription system at the time of the advent of the PIWIS system. You may be able to find someone selling a print copy of the last updates somewhere on the web…….

[harryrcb]

Originally Posted by JFP in PA

You can no longer get them; they went out of print when Porsche stopped printing the manual sets and switched to an electronic subscription system at the time of the advent of the PIWIS system. You may be able to find someone selling a print copy of the last updates somewhere on the web…….

Thanks. BTW what do you think of either Mitchell or Alldata ? Do they have enough data to make it worthwhile. I believe Mitchell has an electronic manual for single car for around $29/yr and alldata has a similar offer for around $23/yre or 44 for 5 yrs

[JFP in PA]

Both are OK in general, but all these services have weak spots with any particular make, and Porsche is anything but an exception to that rule. While often hard to decipher, and totally dependant on hard to find and expensive specialty tools, the OEM manuals are still the best.

[harryrcb]

Originally Posted by JFP in PA

Both are OK in general, but all these services have weak spots with any particular make, and Porsche is anything but an exception to that rule. While often hard to decipher, and totally dependant on hard to find and expensive specialty tools, the OEM manuals are still the best.

I agree about the OEM manuals but it does not apply to the new cars I have a project that I'm working on and need the 09 Manual but cannot afford the $5k per year to access the electronic one.