dr bob

I'm into the first of the winter projects, motor mounts and oil pan gasket replacement. Tom at 928 International supplied the aftermarket mounts which are now quite common. I believe that these are the same mounts that Roger offers. A recent thread here mentioned the "extra" pin in the top mounting face, and how some vendors grind that off before the mounts are shipped. The mounts from 928 International do not have the pins ground off, and it turns out that it's a Very Good Thing.

The Porsche mount includes a rectangular indexing "boss" protruding around the top stud. When installed, this boss fits perfectly in a rectangular cutout in the upper bracket, keeping the bottom pin in the correct alignment to index into the crossmember.

To duplicate the function of the original, I decided to drill a hole in the bracket to receive that pin in the top of the aftermarket mount. The pin is 5/8" center-to-center from the stud, a shade over 1/4" in diameter. I measured and drilled the mount so the stud will index the mount correctly.

In the picture, you can see the new hole in the mounting bracket on the bottom left. Above that see the top of the Porsche mount with the little boss at the base of the top stud. On the top right, the aftermarket mount with the little pin, and the bottom right shows the aftermarket mount installed in the bracket, pin indexed in the new hole.

The new hole is drilled next to the big hole, on the opposite side of the bracket from where the safety hook is on the bottom. Looking at the bracket as it is the picture, the larger holes for the block bolts are on the right, hook is at the top right away from the camera, and the new hole is closer to the camera.

In my opinion, drilling the hole and utilizing the top pin maintains the indexing function needed when installing and tightening the nuts on the ends of the mounts. No undue torque is transferred to the rubber part of the mount.

The aftermarket mounts use M10x1.5 nuts, different from the 12mm hardware that the Porsche mount uses. I added some grade-8 hardened washers (not what's shown in the picture), and found that I needed to dress those top pins a little shorter to get the right clamping with the washer there.

Mrmerlin

crafty Dr Bob thats a great idea as its sometimes difficult to center the mount in the upper portion

dr bob

I ended up using some grade-8 "thick fender washers" 3/8 x 1.25" from the local Ace Hardware under those top nuts. The original bottom washers will be used, with a grade-8 standard 3/8 washer directly under the nut. There are no readily-available washers the same OD as the original but with 10mm or 3/8" ID.

I ended up using a flat file to shorten the pins some, so the end of the pin is a little lower than flush with the top surface of the bracket. The washers are already yellow-cad plated so look like they belong there. Still, another "modification" to document and add to the car's logbook.

For those interested, the mounts were last changed at least ten years and about 40k miles ago now. The engine sits about 10mm lower than when they first went in. I'll measure, and post the New Porsche vs New Aftermarket before-and-after pics when it's all together again. May be this evening, more likely tomorrow before I get back underneath to button it all up again.

ROG100

Our mounts come with the correct hardware.