Once upon a time, I saw here a CAD diagram someone made which showed how deep into the long the "backing plate" of the jack tube went. Since both of mine were gone, I don't have any points of reference and I'm getting ready to fabricate the inner plate and install the new pyramid and tube.

I know I can always grind the tube on the outer end so that it's flush with the rocker panel later if I install it too "proud", but I'd like to have as much tube as possible in the car for the jack to engage in. Make sense?

Does anybody remember seeing that diagram? I wasn't able to turn it up with a search.

Thanks!

On my 75 the jack tubes are 2.5 inches deep. They appear to be protruding into the outer long .5 inches approximately. I think they are original but they do have a primer on them from some work done in 91 by another owner.

This is my research into the same issue. Not sure if this is what you saw earlier or not...

http://motorsport.zyyz.com/project_914_03_05.htm

http://www.914world.com/bbs2/index.php?showtopic=92540

Richard, you rock!

That was exactly the diagram I was thinking of and the fact that the missing values were filled in later in the posts is icing on the cake.

THANK YOU! Now I know where to start from when I get back in the garage.

Now I am concerned that the earlier repair on my 75 is not original in that the tubes are only 2.5 deep and are closed in on the end. The diagram posted shows about 2 7/8 deep. I didn't see the tubes closed in on Richards repair. Are they open to the inside of the long originaly? Surely not.

Glad I was able to help!


The original metal on mine was totally gone (removed by previous owner) on both sides. I had the inner wall that has the recess plus the hole in the recess. Then there is an outer wall (that I was missing) that is also recessed, but there is no hole. So the jack tube does not open up into the inside of the longitudinal. My measurement diagram doesn't show that the recess. It makes it look like it is floating inside of the longitudinal. Later photos down on the page show how I fabricated the outer wall with the recess. I also put in a non-stock drain hole so that water, dirt, etc. does not get trapped in the pyramid.

My car is not finished, so I have not mounted the outer rocker panels (other than a test fit). But I think my measurements are good. I received input from two different people (from unmodified original cars) when I came up with my numbers.