1989porsche928

I just got the camcovers off. I am going to find something to drain the coolant in, the lines are getting in the way. I am going to remove the power steering reservoir to make the re-install easier. Looks like I am going to have to unscrew the electrical parts that are attached to the pulleys.

1989porsche928

I did not write on the pulleys with the red marker. I am not sure if it comes like that from the factory.

Mrmerlin

those electrical parts are called rotors they can only fit one way.
NOTE when the engine is at TDC both rotors will point to the left fenderwell.
The red marks were put on by a mechanic that worked on the car

1989porsche928

I rotated the engine to TDC. The marker on the crank is at 0|T for TDC, I did not see any notches from the front of the engine. I thought it was strange, the notches on the pulleys are on the back so you can see it closer to the covers notches.

GregBBRD

What am I missing here?

Are we actually encouraging someone to remove the cam belt with the engine anywhere but at 45 degrees BTDC?

A pro like Stan, who knows exactly what to do and what not do, plus knows exactly what to do when things start moving, can get away with this....but a rookie?

Sounds like a disaster movie, in the making, to me.

Mrmerlin

Greg your right the belt should be taken off at 45deg BTDC.

I am also wondering why the index marks are missing from the front edges of the cam gears/
The rear hash marks do look correct.
NOTE Belt removal at 45deg BTDC is done so that if the cam should turn .
the valve will not hit any of the pistons.
45deg BTDC at the cams will be 4 valleys before the hash mark.
so thats why you have different red lines being drawn. To mark TDC and 45 BTDC

1989porsche928

Thanks for the reply. I just drained the radiator and removed the hoses. The two valve timing covers are off. Mrmerlin you said to zip tie the belt at the tensioner. I don't see the belt at the tensioner the middle cover is blocking it. I remember seeing a 4|5 before hitting the 0|t. Is their another 4|5 that means bottom dead center

1989porsche928

I thought it was a little strange after watching the 928 training video that you said top dead center. Anyways I am convinced their is only one 4|5 and that means bottom dead center. I attached a picture of the pulleys so you can see the part numbers off of them. Are they China knock offs? What I don't get about the training videos is the fact it does not show that timing ring that was damaged.

Mrmerlin

Whoa........... 45 deg BTDC means........... 45 degrees before top dead center.

so if you had the engine at TDC then the 45 would already have passed the timing mark as you turn the crank CW.

To get the engine to 45 deg BTDC turn the engine around again almost two more turns,
so the cam marks are getting close to lining up with the pointers.
as the 45 comes into lining up with the crank pointer stop.

Now the cams should be 4 valleys away from lining up with the cam pointers.

This is 45 BTDC this is when its safe to remove the belt.

All of this being said since your asking these questions I would strongly suggest to get some help from a local mechanic thats familiar with the 928 ,
as if your not doing things correctly you can easily bend a valve/s
Also reading the workshop manual would possibly give you more information,
if you dont have the WSM then you should just stop working on this machine, till you get it and read it

Leon Speed

My eyes might be deceiving me but the right cam sprocket appears to be riding very close to the cam backing plate. Looks like some rubbing occurred as well. Maybe just the angle and lighT at play. Any chance the cam backing plate is loose?

Mrmerlin

http://s560.photobucket.com/albums/s...End%20Refresh/

Hilton

No, they're just the early cam gear part. Someone either installed old-stock from somewhere, or fitted used gears off an early 32V engine.

The 00 suffix on the part number was superseded by 01 which was the mainstay on the S4-onwards cars for years and added the front "groove".

1989porsche928

thanks, I put the engine at 4|5, im going to grab some zip ties from the store and continue working.

1989porsche928

Here is what the damaged ring looks like:


I am thinking about buying a new bracket for the hall sensor, it looks a little bowed and wont sit flush on a flat surface

Leon Speed

The bracket doesn't matter since the hall sender sits flush on the cam backing plate.