Wisconsin Joe

85 Euro with the twin dizzy.

I'm getting leaks from the cam carriers (seems to be either the front cam seal or o-rings in there)

So I get to basically do a TB/WP (probably not going to replace the WP because it has less than 20k miles on it).

Following Dwayne's and a couple other pic heavy writeups.

In the stuff I'm reading, the crank gear for the TB should just slip off. Mine is on pretty good. I even tried a 2 jaw gear puller, but just bent the timing belt guide.

I've hit it with penetrating oil, tapped (gently) on it, tried tapping the woodruff key into the slot better (Dwayne mentions that).
No go.

Any suggestions?

Also, it has the M28/41 twin dizzy. I've pulled the hold down bolt, the wires and the caps. WSM simply says "unscrew the distributor and pull it out of the engine block."

It won't pull out and I'm reluctant to pry or yank hard on anything.

Any suggestions on that?

Thanks in advance.

Mrmerlin

a torch may be needed on the gear careful you dont melt the rear timing cover,
a 2 finger puller hooked onto the rear side of the rear thrust washer should pull the gear off.

NOTE make a pressing pin for the crank,

this is a 18mm bolt head that will sit on the snout face that you have drilled a small dimple into the head so the puller center pin will seat in it.

you dont want the puller to have it go into the threads of the crank.

Dizzy should come out after removal of the 13 MM bolt that anchors it to the lower cam guide housing, use some heat on the lower housing.

Then try tapping the housing with a block of wood and a mallet ,
NOTE leave the bolt in a few turns so the dizzy wont go flying.

Wisconsin Joe

I was using the crank bolt in place as a pad for the puller. But thanks for throwing that in.

I am hesitant to use a torch on it because there's leaked oil all over the front of the block. I was hoping not to have to use it. Oh well.

And the dizzy housing just pulls out? Nothing but the bolt at the top? That's what I thought, but I wanted to make sure.

Thank you for your prompt and detailed reply.

Mrmerlin

Joe your welcome.
I wouldnt worry too much about the oil catching fire,
use some wet rags to cover the surrounding area.

NOTE if you have the WSM there is a detailed description of the twin dizzy,
and how it comes apart,
If your removing it then its a wise decision to replace the belt.

Wisconsin Joe

Thinking about the dizzy belt.

There was a full TB/WP done at a Porsche dealer in late 08. PO told me that this dealer had one of the last active factory trained 928 techs around (he retired a few years later).

Dizzy belt was replaced at that time. WP was a factory Porsche. I'm guessing the PO balked at the additional cost to replace the 3 gears because they have gone through the coating and into the metal. Yes, they will be replaced. Putting in a PorKen tensioner too. Since the belt isn't much, that will be new too. I'm just balking at the cost of a WP and while I don't mind paying it, I don't want to do it unnecessarily.

It's been leaking a bit from the front left of the motor since I got it. Last summer the leak got noticeably worse. So that became my winter project. I thought (hoped) it was just the cam covers. Then I found out that the 16 valves don't have cam covers. Oops.

So, after a bit of research on here, I found that to get to what is leaking (front cam seal), I have to basically do a TB/WP. Yay. Thanks to all the info available on here (and stuff like Dwayne, which I count as "from here"), it's been going fairly smoothly.

And yes, wet rags, a soaked towel nearby, and a helper with a fire extinguisher are all standard procedure for me with an open flame in the engine bay.

Wisconsin Joe

Ok, the dizzy came right out. It turns out that the little o-ring was stuck inside the housing. Knowing that there wasn't anything else holding it in, a gently pry upward popped it out. I didn't think there was anything else holding it in, but I didn't want to pry on it without some reassurance.

Crank gear is still on though. I ended up stripping out the inside threads on my very old and tired 2 jaw puller.

But I'm making progress.

soontobered84

For the crank gear:

Use PB Blaster/ Kroil or som kind of penetrating oil.
Disassemble a leg from a 3 legged puller. (most of these have "hooks" on both ends but 1 hook faces one way and the other "hook" faces 180 degrees out.
Slide one end of the leg under the crank gear(wherever it fits)
Hold the puller leg with one hand and tap the opposite "hook" with a hammer.
I use a 3 lb ball peen with a metal shaft and just slide the metal shaft down the leg until it contacts the opposite "hook".

Generally, all you have to do is break it free and get it moving and it'll come right off.

Good luck

Wisconsin Joe

Ok, thanks.

I've already hit it with penetrating oil.

I hadn't thought of the "hook something on the back and hit it forward" technique.

I've tried the "pry on opposing sides" trick, but that hasn't done anything. Partly because there's nothing solid behind to pry against.

Mrmerlin

here are some pictures of what the twin dizzy should look like when it comes out and when its seated.

You will note that the rotor points to the anchor bolt when you go to install it.

after installation You will note that the leading edge of the rotor is lined up with the hash mark of the dizzy body.
Look carefully you can see the yellow paint mark on the body of the rear rotor

I should have mentioned that you can also drive a screwdriver into the opening of the base and the cam housing to lift the Dizzy out

Wisconsin Joe

Thank you Stan. That's exactly what I did. As I said above, I didn't want to start prying on it without making sure I wasn't missing something.

I'm at TDC so the cam gear is on the mark, the dizzy rotor is too.

Everything is making sense and (except for the crank gear) has come apart just the way it was supposed to. All the bolts seem to be torqued properly. None were loose, none terribly difficult to remove.

Hell of a learning process.

Mrmerlin

to remove the front cam housing the rear timing cover comes off first then the cam pulley then the front woodruf key.
NOTE there are two woodruf keyways on the dizzy cam,
after you remove the front key then tap the housing out.

NOTE on the dizzy side there are 5 seals to replace
the front radial seal,
the O ring seal that rides inside the front collar,
the fat O ring seal for the housing ,
and the little doughnut shaped one for the oil path.
last is the dizzy seal, This seal you may not want to change,
is the seal on the top of the dizzy housing just smear some DC 111 on it

Wisconsin Joe

Thanks as always.

Cam gear & 1st key are out. Rear cover isn't coming off until I get that #%@%$&% crank gear off. But I did get the little bolt that holds the rear cover to the front cam housing.

Dizzy seal looks pretty good. I may replace it anyway. Other four were already on the "I don't want to do this job again for something that stupid" replacement list. I love the exploded drawings in the PET.

Going past the storage on my way to do other stuff, going to hit it with penetrating oil again. Hopefully will get a chance to try again later today.

Wisconsin Joe

Ok, it's finally off.

Thanks everyone for their help. There was a bit of rust under the gear, that's what was holding it back.

Using the "hook behind the gear and hit it" in post #7 got it moving just a bit (just enough to see the scratches on the crank disappearing under the gear very slowly.
Small puller on it popped it about 1/16", but it held up there. Hit it a few more times, put the small puller back on and tightened it to the "I don't want to go any tighter" point.
Realized that the distance it was popped out gave me enough room for the bigger puller. Got that one tight, cranked slowly and gently on it and the gear came off.

The rust doesn't seem to go deep into the crank surface. I think it will polish off with a bit of crocus cloth.

Got the rear timing belt cover off, the oil pump looks like it's ok. The oil on it looks like it was coming from above.
The front cam housing came off reasonably easily (tapped it gently with a wood handle) and that seems to be where the leaks are coming from. Cam seal is leaking, the O-ring between the housing and the cam tower was leaking some, and the oil path seal was cracked.

Now to clean, order parts and put it all back together.