[tamathumper]

Congratulations! And how did you determine that was the problem? Did you find the disintegrated connector by inspection, or did you find it by performing the tests in the workshop manual?

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[Bulti]

It came to mind that last winter, when I changed my flywheel and clutch, I already noticed some tape wrapped around it. Off course, this was put on my "what to check out when I have some time left"-things, but forgot about it!



So now I pulled of the tape to see how bad it was, and I suddenly held in my hand a bunch of loose wires and little pieces of black plastic, hmm.



I do not know how the thing was still working before I did my belts, but in any case, pulling the tape off gave it it's "coup de grace".



Lucky me it was the connector at the sensor's side, so I could just hook a new one on :-)

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[Bulti]

BTW, any suggestions about my vibrations? I checked the "Ultimate Belt DIY"-post, but Flash clearly has other stuff on his mind.

Shall I dare to ask him again for the ETA?

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[flash]

lol - no. i'm not even going to think about that for at least another 6 months. i'm slammed through january.



as for your vibration, i do not think it has anything to do with belts, if it is off throttle only. that sounds more like a driveline thing. i'm not sure what "shift back" means though. can you describe exactly what you are doing and what is happening?

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[Bulti]

Well, off throttle everything seems to be fine. Then, when I start to drive, the are a slight vibrations, I can feel those all the way through my gaspedal. By "shift back" I mean shifting from for example 6th gear to 4th on the highway (oops, prob bad translation from Dutch to English - is shifting DOWN correct?).



When doing this, when the engine tries to slow itself down, and the revs go up, the vibrations go times ten. Oddly enough, when I took an offramp this morning (while shifting down (?)), the vibrations even got worse... <img src="/forum/images/smilies/968/blink.png" class="smilie" alt="" />



Since my engine and drivetrain never had such poblems before changing my belts, I strongly suspect my (Contitech) balance shaft belt...

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[flash]

belt vibrations are very consistent. they tend to peak at about 4k or so, but do not change relative to shifting, gear, or anything like that. if the balance belt is off alignment, you will get a vibration. it will have nothing to do with tension though. it's entirely related to position.



i tend to think you have one of a couple of things going on.



downshift judder is almost always clutch. a glazed clutch can do this very easily. it happens all the time when people re-use a pressure plate, and happens sometimes with a flywheel that has suffered a burned clutch disk. just like brakes, you cannot put contaminated items back into service. if there is any "bluing", scoring, or discoloration on either the flywheel, or especially the pressure plate, it must be replaced. a tiny amount of grease or oil on the disk will cause this too. too many times i've seen people change their clutch, only to either ignore the rear main seal, or put the wrong grease on the fork bearings.



it could be driveline. the torque tube bearings could be going, or you may have slipped the collar on the bearing. this is actually becoming a more common issue, particularly on cars that run light weight flywheels.



it could be input shaft related.

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[Bulti]

But isn't it at least a bit strange that none of these problems occured before?



My clutch and flywheel have been replaced very recently with brandnew parts. My clutch isn't slipping or anything...

The only thing I could think of which is wrong with my driveline is my firewall that has to be fixed properly. It's been welded, but not entirely as it should be, the clutch engages far too close to the ground. Both my master- and slave cilinders are brandnew, and so are lines connecting them. The firewall must be still flexing a tiny bit....

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[banditsc]

Check to make sure the balance shaft pullies are properly lined up, they can easily slip 180 degrees while your installing the belt or tensioning.

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[gbarrier]

Sounds like a balance shaft gear 180 out.



The guy who owned my current 968 had the belt changed at a reputable shop. As soon as I drove the car I suspected it was out. Am guessing that the gear was 180 out when they did the belt and just put it back the same way.

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[Bulti]

[quote name='banditsc' timestamp='1376496948' post='147229']

Check to make sure the balance shaft pullies are properly lined up, they can easily slip 180 degrees while your installing the belt or tensioning.

[/quote]



My bottom sprocket WAS indeed upside-down, but I already corrected this. Now they are nicely alligned with the notches, the upper at the 12 o'clock position, the bottom at 7 o'clock. The bottom "o" is showing through the rectangular opening, the upper through the round opening.



It must be something I did wrong, but I changed all front seals, the belts the VarioCam chain and -pads... So were to look first? If I put the cam sprocket at <acronym title='top dead center'>TDC</acronym>, everything lines up nicely, the upper balance sprocket is off by not more than half a tooth, but according to Clark's garage this is not uncommon and is not an issue.

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[flash]

it's not about the notches. it's about the keyways. you can have the notches lined up and still be 180 off.



as for the clutch, if you didn't replace the pressure plate, then you may still have a problem there. the only reason i say that is the downshift issue. balance shafts will have no impact on downshifting. the vibration will be the same regardless. it may be though that you are noticing it more merely because that downshift coincidentally puts you in the higher vibration rev area.

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[Bulti]

I will check the sprockets once more, but isn't it true that, when the "O" mark in showing in the correct slot of the sprocket (round slot upper, rectangular slot lower) cover, the keyway prevents it from being mounted on the shafts the wrong way? Therefore, if the notches line up, the oriëntation of the balance shafts must be right?



The pressure plate is also brand new...

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[flash]

yes - and no



the gear can go on either way. they use the same gear for both locations. keyways both must point up, but there is one notch for the upper and one for the lower position. that's what messes people up



   

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[Bulti]

You are absolutely right about this, but I know for sure my sprockets are mounted the right way on the shafts.



Thing is, I just checked the sprockets again and guess what? The bottom one doesn't line up with the 7 o'clock notch anymore... It's now at 3 o'clock. <img src="/forum/images/smilies/968/whine.gif" class="smilie" alt="" />



So, unless I'm going completely crazy, the belt must have skipped some teeth after I adjusted it a couple of days ago (a previous post). Probably too much slack in the belt?!



Anyways, I will correct my error (again) and pray for a P9201 to fall out of the sky.



To be continued...

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[Bulti]

Balance belt working fine! Finally!



Even the irritating noise went away! It seems that the right tension in combination with the idler pulley NOT touching the belt did the trick for me!



Woehoe!

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[flash]

that idler pulley is there to prevent belt slap. you should have a small amount of deflection 0mm-1mm). it should always be touching though. without it the belt will go slack on one side at high rpm, and you'll be right back where you started.



look carefully at the diagram. it is fuzzy, so it looks like a gap at first glance, but it is really the amount of deflection



   

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[Bulti]

I will keep an eye on it, on the upper side it touches, but barely. When the belt needs to be readjusted after about 1500 km, I will check if everything is still ok.



Thanks a lot for your help! If any of you guys goes to Europe for a holiday, don't forget to stop by, I'll buy you some beers!



Next om my to-do list: loose firewall, sweaty oil pan gasket, overhaul servo pump, new paint job, new "bat-wing" undertray... Sigh...

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