Porsche Enthusiasts Club Forum

Gentlemen ,
I need the combined skill and expertise that exists on this forum please.

I'm in the process of replacing all the front of engine seals on my S2 cab , and slowly everything is coming off as it should.The balance shaft sprockets are off , as are various idlers , tensioners , Crank Pulley and crank balance shaft sprocket.However the timing belt sprocket on the crank is proving troublesome.I cannot remove it from the crank .I've tried a puller on it , but to be honest there isn't much space to get the puller legs onto it and as I tighten up the puller , it slips off.I've tried levering with screw drivers but am a bit frightened of damaging the oil pump casting.The key is still in the keyway on the crank and I don't think that will come out until the sprocket is off.Am I missing something blindingly obvious , or is it a case of more brute force needed?Has anyone else experienced this and if so how did you get round it?

Thanks guys

Toby

Hi Toby -
I am not a fundie on this but I think the key is a lock for the cam sprocket onto the crankshaft. ie I don't think that you can pull the pulley off with the key in place. As the whole assembly is only held in with one bolt, the key would be incorporated to secure the pulley: remove the key should free the pulley. Just an idea -

Dave

There is a German chap on youtube that does both belts and all front engine seals on an S2. You can put the subtitles on.
Not sure on how to put the link up! Very informative video though and might just help.

just search porsche 944 s2 its one of the most watched ones.

regards

Mark

They can be a little tight ... I had discussions with one of JMG's mechanics (apparently it's one of John's favourite tasks to give the novices!) about getting them off. You can just tap them to loosen the bond, they will come off eventually, heat is always a good thing in moderation...

My Cab was relatively simple as I'd taken off the radiator and A/C cooler so I could get at everything through the front which makes things a lot lot easier IMHO - especially if you're doing belts as well simply because you can see everything and reach everything without any significant obstruction. I don't recall any major difficulty getting the puller on - are you sure the puller's 'teeth' are sharp?

The other thing that nobody tells you is that the crankshaft key is different to the camshaft/balance shaft keys. The crank key is what is known as a feather key which looks like a section of rectangular bar (imagine a long thin brick) whereas the cam and balance shaft keys are conventional woodruff keys





The woodruff key can be pushed out normally, but the feather key must be lifted out - best with a pair of end cutters.


I didn't realise this and was banging away at the 'stuck' key thinking it was a woodruff, but all I was doing was jamming it harder into the keyway. I ended up having to weld a small lever onto the f ucker to get it out.


HTH

Greg

No. The sprocket comes off with the key in place.


From about 7:30 here:

Keys should stay in the shaft as the sprocket comes off ... Watch as the balance shaft sprocket comes off...

Thanks Guys , especially Mark/Jim - that Youtube video is very good.I guess suitable heat and penetrating oil/brute force is needed!!Hopefully will be sorted over the weekend , assuming I get over the excess of food and alcohol over the next few days!!

Toby

Well, have you pulled it off yet?

Not yet!! Large engineers fine adjusting tool booked for the weekend!It will come off - maybe in bits though.I've bought another sprocket in preparation for massacre and demolition of the current one.I'll keep you posted.

Toby

Here how I did mine !

Balance shaft belt sprocket was easy , but my sticky bit is the camshaft belt sprocket - cant get a puller behind the sprocket ( lack of clearance between it and the oil pump casting).Going to try easing it out enough to get the puller on with chisel!!Have tried a 3 foot long wrecking bar to lever it and the wrecking bar just bends!!

Toby

Lord have mercy!!

In approaching three decades of doing these I have never had to use a puller to get that pulley off.. but there is a trick to it.

Vibration is the key...

Use a small hammer and tap all around the sprocket, over and over again and when you try to get it off, keep tapping it and easing it on one side and then the other.

Sometimes you might get it to move a fraction and then it will bind up again, just keep working it and it will come off.

But seriously, lots and lots of vibration will do the trick.

Well , it's off!!
Jon , tried the vibration trick ( the wifes rampant rabbit will never be the same again !! ) , but made little impact.Eventually drilled down to the feather key and spread the sprocket with a chisel and off it came!!Fortunately , I've bought a replacement sprocket and feather key.Looks like I need new top hats , though as there is a scoring on them.
Happier days!!

Toby

Good to see itself off, albeit with unconventional means!