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Engine Specific Info and Questions => IDI Engine => Topic started by: lloydbiker on December 23, 2010, 10:03:58 pm
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Can anyone explain to me what is different about AAZ flywheels? I need to replace the clutch in my '97 Jetta TD (CDN AAZ engine) I see notes re: a compatibility problem between Sachs (German) pressure plates, and LUK (Mexican) flywheels. What exactly is the problem? From what I read, one has 7mm dowel pins, the other 7.4 mm, but which is which?
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one has a single dowel pin (mexican) and one has 2 dpwel pins (german)
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I will assume the Mexican is the 7.4mm, as it's the single, and the pins appear to be in the wheel. Do you know if the pin circle centerlines are the same? If so, wouldn't it be possible to drill out the pin holes in the pressure plate to 19/64 (.005" clearance), and use the German plate with the Mexican wheel?
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you gotta know what one of the location slots to slide the dowl pin into on the pressure plate. other wise you will be 120* off in timing your engine..
my rabbit has a german pressure plate, and a mexican flywheel off an ABA engine. the groove in the pressure plate was just ground slightly bigger with a grinding wheel it looks like..
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So, in fact, the pin goes in a slot, rather than a hole, or has somone modified your plate to make it fit? So, the trick is, when replacing as a kit, get the pressure plate oriented correctly first, then make sure the flywheel is in sync, or you'll have trouble with the timing marks? I also assume there is more than one slot, if there are supposed to be two pins in the German wheel, and they are 120 deg apart? The pictures I've seen look like the pins could not possibly be diametrically opposed, because there are three torque transfer bars on the pressure plate.
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Now here's a weird one for ya! There is a supplier, here in Canada, that shows the following as available :For Jetta TD (AAZ engine), up to '99, Clutch kit (specifies flywheel must be changed if it's LUK) $228. Flywheel, up to '94, German, 2 pin $132+$2 for the pins. Also: Flywheel, '95 on, OEM (Mexican?), 1 pin, $340. all prices $Cdn.. So, it would appear, if you suspect you have wear problems with disc, plate and wheel, one should definitely go all German, and be done with it.
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Being a belt-and-suspenders kinda guy I always install entire clutch kits... pulling trannys or engines is such a pain and a couple hundred bucks spent knowing your flywheel is true and your pressure plate is straight are cheap peace 'o mind for me. ;)
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Vince: Do you agree the following is what I need for full clutch replacement on my '97 Jetta (AAZ engine) regardless of what flywheel it currently has?
From autopartsonlinecanada.com
1-I2030-90685 Sachs Clutch Kit
1-I1000-38376 Sachs Flywheel
2-I1110-137386 Flywheel Dowel pin 6.2x22mm
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I'd think so... checked at BestPrice as well... definitely issues a warning that the Sachs and Luk parts are *not* compatible, so you gotta go for a matched pair.
Dunno if you need the flywheel pins or not... I would have thought they came with them... and *yikes* that flywheel is definitely more expensive then the last time I bought one... but it certainly looks like you need a matched set.
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autopartsonlinecanada.com definitely states the pins are separate, and R.O.R-2.0 said above that he's running a slightly modified German plate with the Mexican flywheel from an ABA, although I have no idea what engine he's running. So it looks like mix and match is workable with slight mods, but only one way. But then, probably no-one has a new Mexican pressure plate.
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autopartsonlinecanada.com definitely states the pins are separate, and R.O.R-2.0 said above that he's running a slightly modified German plate with the Mexican flywheel from an ABA, although I have no idea what engine he's running. So it looks like mix and match is workable with slight mods, but only one way. But then, probably no-one has a new Mexican pressure plate.
was on a 1.8 8v engine, now its on a 1.6TD.
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There is a slight additional difference the single dowel system has small tangs on the pp to help keep it centered. Although i don't see what it effects of any concern. I have also modified the pp to run the larger dowel and its functional.
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i never had 2 of the same plates to compare, but with different manufacture origins..
cant tell if there is a difference for sure. but i know the dowel pins are a tiny bit bigger on one of them.
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There is a slight additional difference the single dowel system has small tangs on the pp to help keep it centered. Although i don't see what it effects of any concern. I have also modified the pp to run the larger dowel and its functional.
supposed to be a balancing deal. If the PP is off center the bearings wear? Our diesels don't even have a harmonic dampner IIRC so I don't know why it would be too bad. The bolts should center it for the most part anyway.
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i do remember the pressure plate on my setup did center on the pressure plate.. even with the bolts out, there was no play..
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[supposed to be a balancing deal. If the PP is off center the bearings wear? Our diesels don't even have a harmonic dampner IIRC so I don't know why it would be too bad. The bolts should center it for the most part anyway.
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The AAZ does have a Harmonic Balancer, as part of the serp belt system though, and I can see where having the locator notch, without the pin, could cause a very slight imbalance.
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[supposed to be a balancing deal. If the PP is off center the bearings wear? Our diesels don't even have a harmonic dampner IIRC so I don't know why it would be too bad. The bolts should center it for the most part anyway.
The AAZ does have a Harmonic Balancer, as part of the serp belt system though, and I can see where having the locator notch, without the pin, could cause a very slight imbalance.
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i believe he is talking about the 1.6, not the 1.9.. ;)
i believe all aaz engines came with harmonic balancers? and even a few late 1.6s?
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Lloyd did you see Mike Malone has an almost-new Sach clutch and pressure plate for sale... dunno if this helps you any?
http://www.vwdiesel.net/forum/index.php?topic=27894.0