Trailing Arm/Spring plate bolt question

[EJC]

I have a '74, 911 and am replacing the rear torsion bars and installing new adjustable spring plates. The lower bolt on one side, which is holds the spring plate to the trailing arm is frozen!! The nut is off, but the bolt is solidly in the arm. I would appreciate advice--does this need to come out to be inspected?? Or is this just a happy bolt that will continue to do its job when reassembled. Thanks.

[ZOA NOM]

That bolt stays there. The nut you removed is normally loosened to adjust toe or camber, I can't remember which.

[Chuck Moreland]

Zoanas, the front bolts adjust camber and toe. The lower bolt simply secures the spring plate to the trailing arm.

EJC, with the nut off that bolt should come out pretty easily. Have you removed all 3 nuts that secure the spring plate to the trailing arm? You do have the car in the air with no wight on this corner right? Gotta pic?

[ZOA NOM]

A picture is worth a thousand words:



Thanks, Chuck, you are correct. I was thinking about the oval shape of the bolt holes at the trailing arm when I posted above. Those two nuts need to be loosened to make any adjustments to toe or camber.

[EJC]

It is indeed one of the bolts that holds the trailing arm to the spring plate. Car is in the air, and the other bolt is free, and the camber and toe bolts are also free and out. Space limitations make a 1/2" break bar almost impossible due to trailing arm. Sprayed wd40 & pb blaster to no avail. I have not gone to the heat yet, but is it really a problem? Thanks for the input.

[imcarthur]

Are you sure the bolt is not just pinched due to the force of the torsion bar? Have you tried jacking up the edge of the springplate & relieving the weight? I started to strip one because of this . . .

Ian

[imcarthur]

And it was the lower one btw.

Ian

[ZOA NOM]

I think Ian's onto something. I had the same problem with mine, also the lower one. I put a small bottle jack under the corner of the spring plate and lifted it just enough to relieve the pressure on the bolt.

[randywebb]

Now somebody write which way to turn each nut does what/how much and we have a nice pic of suspension adjustment...

[EJC]

Photo gives a better idea of my question.

[lateapex911]

So, basically, you're saying that bolt has become oxidized in there?

I would try mild heat on the surrounding area, and then thread a sacrificial nut or two (one as a jam nut) on the threads, with the outer suface of the nut proud of the threads. Now, a few mild raps with a hammer might do the trick.

[EJC]

It must be oxidized, almost as if it were welded. What is the downside of leaving it as is and then doing the reassembly? Any thoughts about that?

[lateapex911]

Oh....I thought you wanted it out as a matter of course, LOL

If the threads are good, then it's doing the job, and should continue to....

But, it will continue to oxidise, and isn't too likely to get better. So, if you can get it out, why not and replace it wth a fresh properly plated version. That would be, in my eyes, the way to do the job 'right'.

But I would venture that it will function fine as is.

[ZOA NOM]

Try putting the box wrench on it, and use an air chisel vee bit on the open end while you turn it. Or simply a BFH to tap it loose. Worst case, you twist the head off and have to drill it out.

[EJC]

Thank you all for the input, very helpful. Other ideas always welcome. I will let you know when I get it out. Thanks again.

[imcarthur]

BFH is what I'd use & just buy a new bolt. There's nothing holding it in but rust.

Ian

[DCred911SC]

EJC, I had one exactly the same when I did my torsion bars. In fact, one of them snapped right off, and one was left like yours. The alloy arms and the steel bolts aren't a good mix, and after salt, water and time the aluminium and steel will react and virtually weld the bolt in place. I tried for 2 days to get the bolt out and ended up cutting it flush, and drilling it out, like I did the one that snapped (only did it bacause I had to do one anyway). If you don't fancy drilling it out, then leave it in, I can't see it doing any harm

David

[EJC]

David, thanks for the follow-up. I was somewhat lucky and able to use the propane torch and hammer method. It did come out, but there were several uneasy moments. I was not looking forward to drilling it out. EJC

[kslizzy]

I just tackled this in the last couple of nights. It seemed my bolts had formed threads onto the trailing arm. I gave the bolt a couple solid wacks with a rubber mallet to break the bolt free then backed it out with a wrench. It might be worth a shot.

Regards,
Kris