Thursday, 6 October 2011

7. Checking End Play and fitting Flywheel seal

We are now going to check the end play of the Crankcase and fit the flywheel seal.

You will need 2 of the soft iron gaskets that fit on the end of the flywheel. One is used to check the end play and then discarded and a new one used for final assembly.
Crankshaft soft iron gasket

Fit it onto the dowel pins of the crank. Note there are two holes that are slightly closer together and these must correspond with the 2 dowel pins that are closer together.

Take the shim that came of the engine and use this initially. It may need to be changed later but it is better to start with the original one.
Now take your (balanced) flywheel and fit to the crank (remember 2 holes are closer together) and then take your old flywheel nut and washer and tighten up by hand.
Take your breaker bar and a 36mm socket and lock the flywheel using a flywheel lock. torque to the maximum you can by hand.

Flywheel lock and 36mm socket with breaker bar

You will need a dial gauge and holder to check the end play. You are aiming for end play between 0.0041" and 0.0071" (4/1000 to 7/1000 of an inch)  ideally around 0.0055"

Dial indicator attached to engine stand.

Push the flywheel in and out and measure the amount of play using the dial indicator. If it is within the range then all is fine, If too much play then you will need a thicker shim and for too little a thinner shim. different thickness shims are available form most of the porsche parts suppliers.

We are now going to fit the flywheel seal. Take this seal from your gasket set. 
Now remove the flywheel and old soft iron gasket. clean the shim. and flywheel nut area. coat the shim with a little engine oil and put into position. 

You will need a seal installer. this is a VW tool 

Take your silicone seal and place in position. Coat the edges of the seal and the sealing edges of the engine case with white grease to aid its installation.

Use the tool to gently install the seal as in the picture below. I am using  a socket extension that runs through the engine stand yoke. Tighten up the seal installer nut until the seal is fully home.

Check the seal is in square. You are now ready to reinstall your flywheel. 
Take a new flywheel soft iron gasket and install. take your flywheel and place onto the crank dowel pins.
Take a NEW crankshaft bolt and washer and tighten with a 36mm socket.
The flywheel nut needs to be torqued to 425ft lbs. I use a 4:1 torque multiplier to achieve this.

Torque multiplier is just before the 36mm socket and is driven by an extension bar that runs through the engine stand yoke

You have now installed your flywheel.


  1. Very good article!
    Points out the fact that two of the dowels are closer together, which might be missed when assembling flywheel,

  2. Great post i must say and thanks for the information. Education is definitely a sticky subject. However, is still among the leading topics of our time. I appreciate your post and look forward to more.
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