Flywheel bolt torque?
 

Having done so many other jobs on the car now I want to do my first ever clutch job and have been reading up on the procedure. I've got the 101 projects book but he mentions two different tightening procedures. One was a 90deg final turn and the other was 120deg. What is the actual correct procedure for these bolts?

Thanks
Chris

Have you posted this question on the Pelican tech forum? I'm sure Wayne would be more than happy to address it.

http://forums.pelicanparts.com/boxster-cayman-forum/

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.

It is an easy job. I'm not too far away if you get stuck and want help. :)

Thanks guys, and JAAY that's very kind of you. I thought the 120 was the proper one but in one photo he wrote tighten to 50%, then final torque, then 90deg further. The 2nd just mentioned the 120 degrees. I'll post the the Pelican tech too.
Thanks,
Chris

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?

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,
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..

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………

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…….

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

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.

Well, they were offering a deal on subscription pricing, if you lease a PIWIS system, for $18,000 a year, they give you access to the manuals for $1,000.............

Seriously, this subscription nonsense is just another “intellectual property” doge designed to keep independents away from the cars, pure and simple. And I used to think that the 986 and 996 printed manual sets were overpriced at $2,300 (each) for the set….

Gee what a deal, where do I sign up? You are dead on about keeping independents at bay.

JFP and Team,

I finally have my adapter plate in my Boxster EV conversion and am going to be assembling the drive train - DC Motor + DMFW (stock) + Clutch Plate (stock) + 5 spd Tx (Stck).

Researched and found the below post and details from JFP on torque specs: FW - 19ftlbs+120deg, Clutch plate - 17ftlbs. Thanks!

What about balancing? I have no tools for balancing...:( Should I be worried about it given I will be using my Warp 9 DC motor and not the engine?

Please advise. Thanks!

Porsche factory components are "somewhat" balanced, but probably not to the RPM levels the electric motor can turn. You might want to consider having an engine balancing shop true yours up.

just for future reference.
final torque on DMFW should be 90 degrees and not 120.
in the 101 book there is a mistake that was copied from the Bentley book.
in the Bentley book it say 90 in one project and 120 in another.

this is from the shop manual.

http://986forum.com/forums/uploads01...1436476176.jpg

And for your reference, the was a later supplement to the Porsche service manual (a3050371, dated 2002) which reads:

"25 Nm(19 ft. lb.) plus 120 degrees."

That later data remains current according to Porsches electronic information system, PIWIS TSI.

Always makes me feel good when my manual agrees with JFP. :D
http://986forum.com/forums/uploads01...1436485271.jpg

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

Thanks all.

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.

JFP,

I checked with a local Machine Shop and they indicated that they balance at 500 RPMs and that's it. They indicated that that is what most shops will do. Given that then does it still make sense on spending $150 and taking the DMFW to the shop to zero balance at 500 rpm?

Separate question, how do people know that their FW is worn out and they need a new FW? My Boxster has 59K miles on it. To me the FW looks pretty good. Also With the EV I am not going to be shifting much and hence the FW (and Clutch) won't wear down as much. How do I make sure that I have reasonably ok FW? If I post some pictures, could someone who knows this stuff make out or it has to be physically examined?

Sorry of my questions are real basic...:)

Try a better balancing shop. In any case, even lower RPM balancing is better than not.

There is a standard factory test for the dual mass that measures twist of the elastomeric component. Porsche has released a Technical Service Bulletin on checking the dual-mass flywheel (TSB 911 8/02 1360). Basically, you are looking for a maximum of 15MM movement between the segment's.

Here is the bulletin for the 996, which is basically the same: http://www.pelicanparts.com/techarticles/Boxster_Tech/44-TRANS-Clutch/DualFlywheelTechBulletin.pdf

Thanks JFP!

When I read your response, I said great, now I can check my FW. Then I said wait, it said twist and how am I supposed to twist it? Rather than ask the stupid question on the forum :) I searched youtube and found my answer...:)

https://www.youtube.com/watch?v=uLp6nlYMssA

I will check it out. Also will check another machine shop.

Cheers for now.

i stand correct, as the manual i have is from 98.

You should check around and see if anyone is selling the supplements, there were over 100 of them for the 986's, some with as many as a dozen individual pages.

I found a good shop that can do the balancing.

Question: Does anyone know if the Boxtser 2.7L engine is internally balanced or externally balanced? The shop owner (it is a racing shop), who is quite knowledgeable, asked the question...

Cheers.

Internally balanced .

JFP,

Attached are some pics of my DMFW before clean-up. Would you agree that it seems in good condition? I tested based on the testing procedure you posted. The twisting results in deveation of about 10-12mm. So that is good. It is identical on both sides.

However, the FW does not go back to the original position (center) when released after twisting. Please tell me that I don't need to get another FW...:) I am planning on taking the FW for balancing today. Hopefully you'll see this message and are able to respond.

Thanks!http://986forum.com/forums/uploads01...1436811160.jpg
http://986forum.com/forums/uploads01...1436811173.jpg
http://986forum.com/forums/uploads01...1436811184.jpg

The flywheel should return to its original position after being tested. If it does not, the elastomer is failing and the unit needs to be replaced.

Thanks JFP.

Bummer. Now I need to get a DMF now...:)

While I am replacing the DMF, and given that I will be mating it with the Warp 9 DC motor and not the engine, should I go for a single mass FW? My clutch remains the same, correct?

Thanks!

If I understand you DC set up, it is a constant torque at any RPM. If that is the case, you can use any flywheel that is properly balanced.

Getting back on topic....
Just finished editing the 996 and 997 today. We hadn't planned on a Boxster version, but can do one.
Sounds like you guys need this:
Here's a copy of the cover
http://986forum.com/forums/uploads01...1436841288.jpg

JFP,

Thanks for your response. Therefore if I can find a DMF for and S model, would that work too? Is the fitment and diameter same or different? Can I use my exisiting Clutch with an S-FW? Or do I need to change clutch too?

Appreciate all the help! Thanks!

Is 17 ft lb correct for the clutch pressure plate. Installing soon. Thanks.
2001 Boxster S

Yes, new bolts only, dab of blue Loctite.