Distributer shaft slop

eps938 · 07-29-2003, 07:26 PM

Anyone know the spec for allowable end to end distributer shaft play for a 1988 911 Turbo? Thanks - EPS

350HP930 · 07-29-2003, 07:50 PM

I'm guessing but I would hope that there would not be much more than 5 thousands of slop in the free end of the distributor.

Jdub · 07-30-2003, 06:23 AM

0.1mm vertical play.

You are going to have a heck of a time finding the bushings for this item.

A kit with pin and various washers, etc. is Bosch P/N 123-7010-00.

Try International Auto Electric at 313-532-5350 and 313-532-3169.

John

eps938 · 07-30-2003, 06:32 AM

Thanks - appreciate the input. EPS

Superman · 07-30-2003, 06:47 AM

I disassembled my distributor once. I'm used to re-bushing distributors since I mostly drive jalopies. Well, this one was tight as a drum. JW said they almost never get slop. As it turns out, I probably caused the Hall Sender windings to break, eventually requiring a complete distributor replacement. So my advice is to wiggle the shaft and if you don't sense much play....leave it alone.

Jdub · 07:50 AM

I am 100% with Super on this one - if it isn't obviously rattling about there is no need to replace those bushings.

That said, I DO believe that 99% of the folks reading this post have never considered pulling and cleaning their dist internals. Why should you do this? Well, it can correct a wandering idle and bring your mechanical advance back to spec.

When you open up your dist you will find two springs with plastic covers on the mech adv posts. Typically the plastic items have fallen away, giving your advance curve a new profile. The springs, possibly worn, may need replacing due to stretch but the real beauty of this operation is cleaning up the mech adv. plate which will be hardened in place via crud and heat which turns the old grease to glue. This cannot be done with WD-40 down the shaft - you have to go in and clean it up.

The work will also let you check the state of your advance pod (the item on the side with the diaphragm). It is not uncommon to find that the arm into the dist from the pod is no longer hooked to the post on the mech adv and thus you have no actuation.

These are corner cases/worst-case scenarios to be sure, but my '78 was very much in need of the work once I cracked it open. I'd very highly recommend a cleanup of your dist for peace of mind and a return to normal operation.

Just my 10cents,
John

EDIT: None other than the famous EarlyS shamed me into this...that ought to convince a few of you!!

eps938 · 07-30-2003, 08:06 AM

Thanks for the input. I have .100" play at this point so it should be interesting to see what I find inside. I have decided to update the distributor to later style C2 cap with male tower wire connex so have the unit out. Car runs pretty well anyhow however. Recently ran 173 in open highway event. Will be curious to see how tightened-up set up works out. Would expect more bottom end and less MPH if play is taken out and lead is set to spec.

BradH · 07-30-2003, 06:00 PM

I started a similar thread about R&R'ing my SC distributor here:

http://forums.pelicanparts.com/porsche-911-technical-forum/121297-disassembling-sc-distributor.html#post899683

Removing the internals of the distributor seem pretty simple, save unattaching the vacuum advance from the mechanical advance plate. Any tips out there? Mine seems to be riveted on.

Thanks,

Brad

john70t · 09:33 PM

Great thread!
My early car has a total advance of about 15 deg max and comes on at about 3500 so it's either smooth with no top end, or bumpy with power.
The distributor slop with points should be cleared up with the Pertronix AC pulse generator, but with the bushings a stitch in time...
(edit: I second the thanks in retard Early_S_Man!!(pun intended)