RSAErick

After successfully removing and replacing the distributor belt (without removing the secondary distributor shaft), I am ready to re-install the primary distributor shaft into the distributor housing. The bearings for the primary and secondary shaft seem to rotate easily and smoothly. So I have a couple of questions:

1. Should the primary distributor shaft be greased? Should the bearing be re-packed with grease? What type of grease to use - wheel bearing grease, white lithium grease, or other?

2. Should the rubber (?) o-ring seal on the lower housing be replaced?

FYI, the process has been relatively simple so far - far better than I expected. Drilling out the gear pin was a bit of a pain, but not too bad. Driving out the primary shaft required some force, but not that bad.

Thanks in advance for your advice.

JasonAndreas

Bosch Distributor Grease?

RSAErick

Yup, that was probably the stuff. Too bad it's too late for me.

I talked to a Porsche dealer mechanic who clearly didn't have time for my question. What I was able to get out of him was:

1. Don't use white lithium grease because it will turn to concrete. (???)

2. Don't use wheel bearing grease. (I don't know why not)

3. Just use a touch of motor oil. (Which is what I did)

Anyway, I was most concerned with the open bearing at the bottom of the primary shaft housing (especially since I didn't remove the secondary shaft... thanks to Jason and John Walker's advice). I didn't use brake cleaner on it, so I suspect that it retained any lubrication that was already in there. But after 115,000 miles, it would have been nice to get the proper lube in there.

Next time.... Bosch Distributor Grease.

Thanks!

e911

Erick,

I am probably going to do this in June. You didn't have to remove the the secondary distributor shaft. Anything special you did here? Any other tips?
Thanks
Ps where does one get the bosch grease.

KirkF

I replaced the bottom O-ring with one of the new style viton green ones, and repacked the bearings with synthetic bearing grease. The bearings are not easily replaced as Porsche does not list them as a part. Mine were full of rust.

Kirk

RSAErick

Here are the references that I used:
https://rennlist.com/forums/diy-964-1989-1994-911/219861-distributor-belt-replacement-thread-collection.html

It's true that there was no need to remove the secondary distributor shaft. The upper and lower housing separates about a 1/4 inch with the secondary shaft still in place. This provides enough space to remove the distributor belt.

In my opinion, the hardest parts were:

1. Drilling out the roll pin that holds the gear onto the bottom of the primary shaft. I broke a small drill bit in the roll pin as I was drilling it out, so I'd advise starting with a larger bit than I did.

2. Being confident that you have the primary and secondary shaft lined up respectively. I had to move the belt gear a step or two forward and backwards to convince myself that it was in the right tooth. Even then, I never felt that the primary and secondary shaft were simultaneously pointed perfectly at the TDC marks on the housing. But once I proved that forward or backwards a notch on the belt was even further off, I fell confident enough to believe that it was in the best position.

3. Inserting and mushrooming the new roll pin. It takes a big C-clamp to get enough pressure on the primary shaft so that the holes line up. Once the roll pin is in place I had to fabricate a way to hammer the roll pin so that it would mushroom out and stay put. I used a finishing nail set, and placed a socket under the pin to provide sold surface to drive the pin against.

In summary, doing it again would be a breeze. But there are enough unknowns when doing it the first time, that it's a bit of a challenge.

Other than a large C-clamp and a nail set, there are no unusual tools required.

Best of luck!

JasonAndreas

Pelican Parts sells its and most automotive supply shops will sell it or can order it from Worldpac.

Obviously a drill press will help tremendously in a situation like this but the one change that I made to my drilling routine that led to the biggest improvement has been to no longer use garden variety hardware store drill bits. The old retired machinist that works at my local hardware store sent me off to buy tungsten carbide coated bits and told me to use tapping/cutting fluid whenever I cut or drill into metal. The change was night'n'day compared to the titanium//etc. stuff I was using.




For future reference for others; you can drill out 1/3 or so of the pin and then punch out the rest.