[Grady Clay]

Tom,

Great.

What is the difference in profile of the old face that originally contacted the transmission axle flange with a gasket and the new face that contacts the end-cap?

Please post the axial thickness of the inner races of both old & new CV joints.

Does your axle use a conical spring washer?

What is the measured dimension on the axle shaft from the circlip grove to the seat?

How many splines?
What diameter? (This is a difficult measurement because of the splines.)

Please measure the axial thickness of the outer race of the CV joint.

Compare the ball diameter.

Post a comparison between the joints of the ability of the center of the CV joint to move axially.

When you have the transmission axle flange available, carefully inspect the clearances between the end-cap and the inside of the flange.
There are several ‘course-spline’ 108 mm flanges with various clearances for the cage, balls and inner race of the CV joint.


There are two reasons for all these questions:
First is finding the best compatibility for updating our 911s.
Second, Lobro-like CV joints are ubiquitous. I suspect we will see some cars with incorrect joints for the application. We need some idea of areas where compatibility is critical.

For example, what if your new end-cap doesn’t fit inside the transmission axle flange and there is no provision for a gasket. Do you just bolt-up the new joint without either a gasket or end-cap? Do you modify the end-cap? How? Do you machine provision for a gasket?
All important questions – hopefully not necessary.


Another important question about CV joint and axle splines is; what are the specification? Are these DIN, ISO, SAE, other? What specification size, number, etc? I can see some ‘third-world’ part being hawked and not properly fitting (‘fits-all’ clearance).

This is an area of replacement parts where almost every car in the world is using these CV joints. Some may have a wholesale cost sub-$1. I can see the temptation for some of those finding their way into our ‘parts stream’. Not good if they don’t work as expected.

Best,
Grady