Help needed with torsion tube area repair

florio · 01:52 PM

Hi everyone, if you've seen my build thread, you'll know I'm trying to bring back a 72 targa. Sadly, the area of the inner fender near the torsion tube was terminally rusted and I had to get one of those kits that come with a sleeve to repair the end of the torsion tube. Now, I'm trying to understand how it goes together and I need some help as I do not know for sure what it's supposed to look like once functional.

First question: The parts catalogue shows a "spacer ring" (part no 37 on the diagram below, 901 331 107 00). Does anyone know what this is for? It seems to me that the radial arms were fitted on this car without any spacers. Do I need them?

Then, the metal replacement panel I got comes with holes where to weld the captive nuts. I'm guessing that the three longer ones should stick out by 18mm, is this correct?

But, the hole for the shorter nut is very large, why is this? How should I weld the short nut in place?

(note, photo is upside-down, large hole for short nut is on top!)

Any and all help appreciated!

Dario

jpnovak · 01-16-2016, 02:19 PM

The spacer ring is for clearance on the spring plate. The two top and lower forward welded mounts stick out proud from the body. The lower rear is nearly flush with the body and has the external "spacer ring" as you show part 37. On stock suspension, when assembled properly the spring plate will cover the lower rear spring plate cover mounting hole. So, when you load the spring plate and it moves upward in its travel it will expose the lower bolt. The spacer just makes it the same height so the spring plate cover sits level with respect to the body plane.

florio · 01-18-2016, 11:13 AM

Thanks, I hadn't thought of the fact that the radius arm will cover one of the bolts when assembling. So, if I get it, the radius arm sits a bit off when initially mounted, and then finds the right position when loaded up a little. At this point you stick in the spacer ring and install the last bolt.

Is this correct? I've welded a lot of 911, but never assembled one

I still dont understand why that particular hole is so large! How is one supposed to weld in the bolt properly? It's not like I'm missing experience in welding up holes, but jeez...

jpnovak · 01-18-2016, 11:45 AM

You have it correct. Here are some pictures of the three spring plate bosses.

Cracked Spring plate bosses: The find. The cause. The fix.

The hole is larger because it has a mounting flange flush with the sheet metal. Just a larger diameter place to weld.

florio · 01-19-2016, 03:59 AM

Thanks! the thread you linked to had some excellent information. I seem to remember that some of the later models also had a similar small reinforcement plate welded to the inside of the panel, covering the nuts (bosses). Would you recommend something like this? It would be easy enough while the panel is on my bench, much harder once it's in place.

florio · 01-26-2016, 11:27 AM

Hi, I'm using the cover plate to make sure the captive nuts line up correctly while I weld them up, but something seems really wrong to me! If you look closely, you see that they are not all really level with the steel plate, and that the short one is not centred with the hole.

I'm wondering if this is the way it's supposed to be, or how I can make sure that it is going to work out right. i.e. that the cover plate is going to be located correctly. I removed the old rubber bushing from the spring plates as they need to be cleaned and powder coated. Should I have kept them as a guide? The thing is that without the torsion tube attached to the plate, they have nowhere to go!

This has me a bit stuck, I almost just pulled the trigger on the MIG! Weld now, think later!