Torque spec on SWB ball joints

[Fritter]

I have a Haynes manual that says torque spec on the 2 castle nuts on the early SWB ball joints is 109 ft lb. Not sure that is right, because I blew out a castle nut when trying to torque to that spec. When torquing the other 3, 60-70 ft lb "felt" about right.

I just replaced the one I blew out (stripped) with a new self locking nut, worked good. But I went through two of them, I tried to torque the first one to 109 ft lb and it stripped also?

Anyone know the scoop here? What's the torque spec? I think Haynes is wrong....

[JohnT]

My Porsche "Technical Specifications" book dated Dec. 31, 1967, says

"Ball joint castellated nut, M12 x 1.5 ...............4.5MKP"

By my calculations that's about 32 FtLbs.

johnt

[Fritter]

Yikes, well that explains it!! Thanks for the info.

[304065]

What nuts, EXACTLY, are you talking about?

I did this very job last weekend-- there are several different fasteners in the front suspension and the German translation in the FWM is about as useful as a dog's ass when it comes to actually assembling these parts. The old meter-kilopond measurements are illegal today, so you won't find any modern torque wrenches calibrated in MKP, you have to convert to foot-pounds or NM.

First you say, "2 castle nuts" and then "the other 3." Are you talking about the:

1) L-shaped ball joint that mounts in the control arm with two screws, and the pin of the joint protrudes through the triangular part of the steering arm and is secured by a M12 x 1.5 castle nut and cotter pin (which is 34-foot pounds).

or

2) The ball joint pin that goes through the END of the steering arm, which is M10 x 1.0 pitch and is also 34 foot-pounds?

[Fritter]

It is confusing! I meant the big guy that slides into the control arm. I'll have to back the torque off on those guys.

Thanks everyone, where else could I ask these obscure 911 questions and actually get answers?

[304065]

Mike, get yourself some yellow paint and brush it on the nut and cotter pin after you set the torque. This will come in handy when you go to assemble everything and you are doing the final torque check- no wondering "did I torque that castle nut that is now inside the strut? Did I torque those four M10 bolts that hold the brake caliper carrier to the strut?" Etc.

When you put it together you realize why the factory simplified the suspension in 1969.

Also don't forget to get new lock plates for the steering arm-to-strut bolts-- 901 347 481 01- picture shows two per side, but I used three (there are three bolts) and PET says six.

[Fritter]

The yellow paint dab is a good idea, John, and now we know why the factories do that when they build the cars!

[edmayo]

Mike, that is the danger in using aftermarket manuals, they tend to throw many details from different years into one book. They may have meant the retaining nut from the LWB ball joint. The prize example of that is once someone brought me the engine he had just built for me to time the cams. I told him I'd time them, but what did he want to do about the cylinder deflectors that were mounted on top of the cylinders instead of beneath them ! He said that's the way the manual shows them. I jokingly accused him of holding the manual upside down. He brought in his Haynes or Bentley (don't remember which) and by gosh they had posed the picture wrong!!

[Fritter]

Ed, yes, aftermarket manuals can be sketchy...the orange Haynes is pretty good for the most part, but it helps to know a little about the cars beforehand before delving in I guess, so one can judge if something is just blatantly wrong, like the cylinder tin issue....yikes.

I retorqued the nuts last night and all is well now.

Now I just need to raise front ride height a bit, do a garage alignment, get new tires, and then I'm set for the summer!!