Rotor Arm Removal

[John Sims]

Typical Porsche over engineering - With my Capri you would unclip the distributor cap, lift of the rotor arm and replace it - Not on a Porsche you don't []

OK guys what is the secret? I fiddled off the distributor cap - a pain in the bum by its self - and find two fixings into the shaft:-

There is an allen bolt and an 8mm hex head bolt.

The Allen bolt is on the shaft of the new part as well so I assme you leave this alone. I did undo it on the new part, to see what happens, but it didn't achieve anything so I put it back again.

The hex head bolt is just under the edge of the aluminium casing so you can't get a socket onto it. it is also slightly recessed into the curved shaft so not ideal to get a ring spanner on to. I tried an open ended spanner but this was looking as if it would round off the head so I gave up on that.

Any ideas chapps?

 

[Guest]

See clarks garage

 

[944Turbo]

Removing the bolt is the correct way but it is very tricky - I bought a spanner from Halfords that didn't fit and ended up using a flat one, from, IIRC my circular saw.
I positioned it at 12 o'clock (4th gear handbrake off) stuffed in some cloth and a 'magnet on a stick' underneath dont want to drop it. I guess the timng belt cover could be reomved.
If its not urgent I could mail you the spanner or is Rick still planning on heading down to see Jon Mitchell?
Tony

 

[John Sims]

Removing the bolt is the correct way

Thanks Tony

This is what I thought as, while Clarks Garage say remove the allen bolt, I couldn't see the point in Porsche providing the camshaft extension as part of the rotor arm replacement otherwise.

I did have a look at removing the belt cover but it was becomming a big job for something I'd anticipated undertaking in fifteen minutes.

I'm up for a belt change within one of the next two services so I may leave it untill then and subcontract. The job has the makings of becoming a pain in the bum and I hate jobs which you get to a point of no return.

Beaky is running, although with an occaisional slight misfire, so I'll avoid a case of - "If it ain't broke, fix it 'till it is!"

 

[944Turbo]

Having said that there are I believe people that sell the allen bolt bit rather than the whole assembly - as comes from the OPC, but I believe you have to smash the old one off.
The full assy. has a type of loctite on the thread of the akward bolt (and the allen bolt).
Tony

 

[John Sims]

The full assy. has a type of loctite on the thread of the akward bolt (and the allen bolt).

After I removed the allen bolt from the new one I found that the rotor arm had in interferance fit on the cam shaft extension bit, so wouldn't come off any way. I did put the allen bolt back in with some threadlock. I don't want that little sucker comming loose.

 

[944Turbo]

As an addition to this thread, I changed a local friends rotor arm, he has an 89 car, it was different to my 90 model, it just had an easy to get at bolt where the allen bolt is on mine and once undone it was easy to replace. The replacement, from Porsche, was just the black bakerlite? bit on the end. There are obviously at least 2 types then.
Tony

 

[John Sims]

I changed a local friends rotor arm

Damn, you're a glutton for punishment Tony []

I've now found an easy way to change the rotor arm.........subcontract. []

 

[Guest]

There are definately two ways the rotor comes - just the rotor and the rotor with the shaft in a combined assembly.

If you purchase just the rotor, which there is little reason not to especially as it is cheaper, there are two items to be aware of. Make sure your allen wrench fits nice, tight and square so you don't round out the flats.

The rotor has some sort of varnish or loctite between it and the shaft. After removing the set screw, attack the rotor with a channel lock pliers twisting back and forth and pulling out. It will come off fine but you will have chewed up the bakelite pretty bad.

Put plenty of blue loctite on the set screw of the new rotor. That screw loves to back out. And make sure the plastic dust ring is in place when the new rotor goes on to keep most of the belt dust out of the distributor cap. 10 minutes at the outside to change out the rotor.

 

[944Turbo]

I am fairly certain the inner bit was different as well, we also both went to the same OPC and asked for a 'rotor arm' mine for a 90 car, the other for an 89.
Tony

 

[Guest]

I have recently replaced the rotor arm on my 1988 924s after doing much research:

1) Remove the small allen headed grubscrew from the rotor shaft
2) Use a hammer to tap the rotor - which will probably cause it to break/shatter and turn the rotor slightly on the shaft. You must be willing to break off the old rotor as it is "glued" to the shaft.
3) Twist off the old rotor with molegrip pliers and clean the shaft with a bit of wire wool
4) When fitting the new rotor arm you are meant to apply a bit of special glue (there is a Porsche part number listed for this, but threadlock will do).
5) Apply a little threadlock to the grubscrew and fit that to the rotor
6) Put the distributor cap back on after leaving for an hour for the threadlock to cure

I would strongly recommend replacing the plug leads - you will find that your car stereo will start to crackle slightly with the engine running once they have seen 100K miles.

Cheers
Mark

 

[944Turbo]

Ref the leads, I think its the age rather than the mileage, opening the bonnet at night will usually reveal if they are 'leaking' I couldn't believe how bad mine were and the car was still running pretty well, smooth tickover etc. There were sparks jumping all over the place.
Tony

 

[Guest]

I had a few problems starting my 1989 944 this morning - the only time in the last six months of owning a car which has run beautifully. It looks like it needs a new distributor but we also noticed one of the HT leads has been rubbing on the headlight mechanism as it lifts. Might be something to watch out for. Just wondered if anyone had noticed this on their own cars.

Marc
1989 944 2.7

 

[Guest]

As far as the wire from coil to the cap, that can rub on the headlight linkages if you don't have the orientation correct. Just twist the boots a bit to get it to lay right. Or use a cable tie.[]

Old spark plug wires can look fine on the surface but are jumping current like crazy. Go out one dark night with a spray bottle of water. Fire the motor up and spray the plug wires. If you see a laser light show it is time for new wires.

Rather than the stock wires, Magnacore has a set for the cars, though I'm not sure if they got a set for the S2 sorted out yet. $57 in the States and pretty good 8.5 mm silicone jacketed wires.

 

[John Sims]

Rather than the stock wires, Magnacore has a set for the cars,

I put a set on my Turbot - they fit, but you don't get any spare play and routing is very crittical.