When I started refreshing this 16v engine it was obvious to see where the oil leaks were originating - the rear of the balance shaft housings...on both sides!
As you can see from the image above - and this was after I started to clean it - the engine was caked in oily grime with fresh pools of oil behind the rear balance shaft seals. It's taken a lot of elbow grease but the engine cleaned up nice enough to begin, what I perceived to be the most arduous task - stripping off the balance shaft housings and resealing them.
With all the necessary new seals ordered up, and Loctite 574 located on eBay (as this was specified by the Porsche workshop manuals I decided to hunt some done) - it was time to tackle the flanks with vigour!
Not having any special Porsche tools meant I had to be a bit inventive with removing the balance shaft gears - they need to be locked in place while the bolt is removed.
With those out of the way then came the dreadful looking cambelt tensioner:
Starting with the lower balance shaft which despite it's awkward location went smoothly:
With all the bolts torqued up in correct sequence the lower balance shaft rotated freely and smoothly - it was then time to begin the upper balance shaft housing install.
This proved far more challenging for some unknown reason and I had to redo the install three times in order to get the shaft rotating smoothly. I had been very careful to keep the shafts separate so that they'd be installed into their original housing - just to be sure. When I torqued up the bolts the shaft would refuse to rotate - which after the second time was an area of concern. However, after removing the whole upper balance shaft assembly and redoing the installation for the third time - the balance shaft rotated perfectly...job done.
Why Porsche thought it necessary to have a floating cap inside the ends of the balance shaft housings is anyones guess - I would have thought that the fewer o-rings the better...
With all the necessary new seals ordered up, and Loctite 574 located on eBay (as this was specified by the Porsche workshop manuals I decided to hunt some done) - it was time to tackle the flanks with vigour!
Not having any special Porsche tools meant I had to be a bit inventive with removing the balance shaft gears - they need to be locked in place while the bolt is removed.
With those out of the way then came the dreadful looking cambelt tensioner:
And finally the housings - which were then carefully cleaned. The machined surfaces need particular attention to remove all the previous Loctite residue - I took my time with this because I want to be sure that no leaks start here ever again!
Lower Balance Shaft Housing |
Upper Balance Shaft Housing |
With the surfaces carefully prepared and throughly cleaned inside & out, I applied some Loctite 574 to the machined surfaces and began reassembly...
With all the bolts torqued up in correct sequence the lower balance shaft rotated freely and smoothly - it was then time to begin the upper balance shaft housing install.
This proved far more challenging for some unknown reason and I had to redo the install three times in order to get the shaft rotating smoothly. I had been very careful to keep the shafts separate so that they'd be installed into their original housing - just to be sure. When I torqued up the bolts the shaft would refuse to rotate - which after the second time was an area of concern. However, after removing the whole upper balance shaft assembly and redoing the installation for the third time - the balance shaft rotated perfectly...job done.
With the new rear balance shaft seals in place the little caps in the ends of the housing no longer move as before - and to sure up the seal even further I applied some gasket sealant along with the red rubber o-ring to fill up the gaps:
Quad Ring parting lines are between the lobes, away from the sealing surface, thus eliminating the problems of leakage often resulting from a parting line’s irregular surface as found on an O-Ring.
ReplyDeletedone many of them ( lot of them under warranty at dealer ) fun stuff
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