Crank Dimensions

Mark McClure · 11-15-2009, 01:33 PM

Hi,

I posted on the tech forum but did not really get the answer that I needed....lots of good advice though.

Crank - 3.0 SC 79.

I need to get a speedi sleeve for the rear main seal......I would like to buy it before I drop the engine. Can anyone supply the crank dimension, depth of the rear of the crank where the seal runs.

The are are several speedi sleeve depth sto buy...would like to get the right one before the job.

Thanks

Mark.....

BURN-BROS · 11-15-2009, 02:06 PM

Hi Mark,

Why not install the seal at a slightly different spot in the case so that it rides on a new area of the crank?

Mark McClure · 11-15-2009, 03:41 PM

Burn-Bros,

Tried that....The seal leaked before the rebuild and then leaked at the perimeter on the case join afer the rebuild. This is the third seal, not sure there is a place that it has not run...just want to eliminate all possibilities and make this the last engine drop before the gearbox rebuild.

Thanks

Mark......

bela928 · 11-17-2009, 02:48 PM

buy the porsche rear main from the dealer. we had a bunch of leaks with the victor reinz

Henry Schmidt · Henry Schmidt's Garage

The best way to repair this issue is to grind a few thou off the crank flange.
Any good seal will handle the difference with little or no compromise to reliability.
Grinding will also true the flange making it perhaps as good as new.
In addition you can tighten the seal lip spring (old VW trick) increasing the tension and sealing prowess.

Mark McClure · 11-18-2009, 05:34 PM

Thanks Henry, I have been tossing up the spring method against the speedi sleeve. In an effort to minimise any chance of a leak I though that the sleeve would remove any rsk of the crank being scored, burred or in any way damaged. It will be hard to grind the crank without removing it from the engine...the plan was to drop the engine remove the clutch/flywheel on the floor replace the seal and put the engine back in again. in an afternoon/overnight.

So the question still remains what is the depth of the back of the 3.0 crank where the seal runs.

Thanks

Mark.......

Mark McClure · 11-25-2009, 02:57 AM

I really need the measrement now....I even got desperate enough to go to the porsche dealer....he had a great little book with lots of dimensions and setup parameters......but no width measurement.

So again can someone please measure the width of the crank on a 3.0 sc where the rear seal runs, in order to get the right speedi- sleeve.

Thanks

Mark........

MBEngineering · 11-25-2009, 03:12 AM

HI Mark
is this any good for you???

or have you this already? there is a tool for fitting the rear main/flywheel oil seal, would you like the size of that?

regards mike

Henry Schmidt · Henry Schmidt's Garage

Quote:

Originally Posted by Mark McClure

I really need the measrement now....I even got desperate enough to go to the porsche dealer....he had a great little book with lots of dimensions and setup parameters......but no width measurement.

So again can someone please measure the width of the crank on a 3.0 sc where the rear seal runs, in order to get the right speedi- sleeve.

Thanks

Mark........

I measured 4 cranks from the shelf and came up with 19.25 mm plus or minus .10 mm.
I hope this is the number you were looking for.
Cheers

Mark McClure · 11-25-2009, 02:02 PM

Fantastic...this is exactly what I needed....thank Henry and Mike...I can start on the engine drop tomorrow and hae it back in the car on Sunday.

Very much appreciated.

Mark....