430 Rear shock mount trouble

That's quite a serious problem and must be put in real pro hands to resolve this (if resolvable). There exist some very hard resins which would be able to support the huge force from the suspension but this can be done only with some serious expensive tools. Try to find out if you can find any specialised handcraft. Otherwise, the only other solution I can think of is back to factory...

 

If it were me I would drill it as far as possible depending on what is behind the holes and retap the threads. There is no resin in the world that would hold that, maybe weld on an aluminum block over holes and drill and tap.

 

What is on the backside of these threaded holes? Is it possible to drill through the frame and use a bolt and nut here?
If so you can grind down the cracked surface and add a spacer to get the level right - and bolt it all together.
It is not so easy to drill by hand and make new threads that will last. If possible a bolt through is much better.

//Anders

 

Weld it.

Remachine it and rethread it.


Not rocket science and not a big deal for a good fabricator or machinest.

 

Yikes! Not good.

It's actually a far more "dainty" looking mount than one would expect for a component that's under such stress.

Definitely worth trying to have repaired as I'd say the replacement cost will not be cheap. That said, I think I'd always feel nervous about every bump on the road and it would be something you would have to disclose in a future sale....... Maybe replacement IS the way to go?

I'd be very interested to see how any repair turns out. As suggested by Anders, getting a bolt right through to the other side (if possible) might be a good idea and perhaps would also allow a plate to be fabricated front and back to help spread the load over a greater area.

Best of luck and do let us know how you resolve this.

 

Hi Fpayntr - just wondering did you manage to achieve a repair of this component?

 

I have metal fabrication company and people bring us items like this all the time. Here are the problems:

A. It is a casting which means junk metal was used during the initial casting process, and it becomes really hard to re-weld good metal rod back to the junk metal. It can be done however if the casting is of good quality.
B. That section of the car needs to be removed so that it can be properly prepared and then welded to be done right.
C. That shock has a huge amount of Shear loading on the bolts so it better be a good job.
D. If you go the epoxy route it will never have the chance to be welded b/c the area will be contaminated.
E. An engine shop might be a good place to start. They might be able to re-weld and then put in a heli-coil.

Good luck....

 

Personally, I would not do any work on fixing the casting.

That's the entire car frame, a one piece frame that is the entire car's structure.

My approach would be to drill the hole entirely, then use studs secured from the inside of the frame, and replace the small bolts that support the upper shock mount with nuts. The studs have to be tight enough. Use a steel washer between the frame and the shock mount.

Also, you could use a nut inside and another outside to make the stud tight. Add spacer rings to the other side of the car in the same thickness as the outer nut, to equalize rear upper geometry, then add lower camber shims to restore camber to your intended settings.