When you say heavier? More meat inside, may help, just have to machine some of it away! Can't see the OD adjacent to the starter gear being bigger, or the nose of the starter motor would not clear? Photo. would be most welcome, and useful. Woking really hard to come up with an elegant solution!
The mk3 8v single dowel pressure plate is pretty much the same as the mk2 style other than one less dowel. The friction disc is the same as a mk2 16v with the larger gearbox input shaft splines. The three lugs you point out on the pressure plate are there to centralise the flywheel onto the pressure plate. They just fit inside the recess of the flywheel. I always leave this bit on the flywheel when getting them lightened. Mk3 8v 020 GTI flywheels are heavier than mk2 ones as they have a larger ring of metal around the perimeter next to the ring gear. Mk2 diesels use the same clutch as the mk2 8v GTI. Not sure if the diesel flywheel is a bit heavier though, and I am not taking the gearbox off my AAZ IDI Scirocco to find out either.
Das is gut! Off to the dealers when they open to see if they have some flywheels and pressure plates to play with! [:^(] Come on, play the game! I took the box and clutch off the PB to study all this!
This is a Mk3 LUK clutch, in my Mk2 flywheel, at the dealers. He did not have a Sachs or Valeo. Lots of nice lugs on this!
Those lugs should certainly help centralise and locate the flywheel. That is if they a tight fit around the perimeter of the pressure plate to the inside of the flywheel? Would a lightened flywheel not help reduce the strain on the M7 bolts too?
i have had that lugs braek off in the past two out of the three and the ones on the pressure at about 64000 miles on a standard 8v i would have very good look at them and smooth the corners or get them shotpend as daved has said it would have better with a hole in the corner this could still be done with care nice picture be the way
The 9 bolt problem: The 9 bolts, on the periphery of the flywheel, have little chance of preventing the flwheel from rotating. They are fitted through a a recess in the flywheel which allows them to move if they want to. They can't really take shear loads as torque is applied. The joint area, where the flywheel touches the pressure plate, is not very good to permit high local pressures and transmit the torque loads through friction. The small diameter bolts, M7, also, don't permit high loads for friction drive. The only solution to establishing two separate systems. One to hold everything together, and one to take the shear loads. The 9 original bolts will hold everything together, if they don't have to take shear. To take the shear, we need a good dowel system. The two spring dowels can not do the job! They are fitted in loose "U" shaped holes which are so close together that they will permit relative angular movement between the pressure plate and the flywheel. This lets you throw the things together on the car. For a solid shear drive, using dowels, we need to line everything up, ream through and press in tight fitting dowels. See below: What we need is some of these. 6 dia x 24 long. These allow you to pull them out again, for disassembly. And, a hand reamer 6 dia + 5.7 mm drill. To experiment I drilled through the existing rolled pins, 3.25 mm dia and then removed them, M3.5 bolt. For the proper solution, you would then drill through with a 5.7mm drill, using a good solid pillar drilling machine, putting 'ASP', on the flanks of the drill, to avoid spoiling the original reamed hole. Then ream through 6mm. You would also drill and ream another hole 120 deg between the originals. Or you can drill and ream new holes 120 deg apart to suit the pressure plate you use. You then screw everything together, using the original dowels to line things up. Then drill and ream through the nice centring lugs on a Mk3 pressure plate. The original bolts are more than long enough. 35mm will do the job, but keep a set of long bolts for final assembly below. Take it apart and fit the pressure plate to the crankshaft. Bolt it up, with original long bolts, hand tight. Fit the dowels and press into place until they are just throught the pressure plate. Tomorrow I will post a way to check this easily. I believe we should use Loctite on the bolt threads. I have assembled the unit with: 3 bolts using medium strength blue Loctite. 3 bolts using high strength green Loctite. 3 bolts no Loctite. With ASP under the heads. Will report the breakaway torques tomorrow.
Thanks, Chris. Looks like the alignment and dowelling should be done before lightening? Accurately fitting a new pressure plate, after lightening, may prove problematical? Will need to think about it!
The test using the various Loctites, or not, proved inconclusive! New test is in hand, will report later. What I will say is: If you use Loctite, then, the bolts need to be turned out, with effort, all the way. The bolts without Loctite spun out by hand as soon as the preload was released! Loctited bolts, even if they loosen, will not spin out!
Without the distraction of a Scottish loony and his lawn mower-powered brewery, a lot can happen in these parts!
The "Scottish loony" has been assisting behind the scenes I will have you know. If I had not been so busy rebuilding three inferior 16v heads I may have been able to be more useful to Daved's quest. Top work there by the way Daved. You do realise you are going to have to drive like a lunatic to try and see if you can get the flywheel to move on the pressure plate! On that note I have a few spare gearboxes for you when the diff bolts let go..... and driveshafts if you manage to break any of them too.
