PU bushings

["Ralf Philipp" <doc.brown@xxxx>]

> For your purpose, you should probably do
> the galvanize first at 450 degrees F, and then do the stress relief bake
afterwards. The reason is that galvanizing can
> introduce hydrogen into the steel, which can be bad if the part is used at
high stresses. The baking operation will tend to
> drive the hydrogen out of the part. I don't know if hydrogen
embrittlement is really an issue for these parts, but you
> never can be too careful.

As far as I know, hydrogen embrittlement *should* not be an issue with mild
steel, but I will do some research on this, to be absolutely sure.

> What happened to your parts such that you need to weld them? Are you just
reinforcing them,
> or repairing them? Just curious.

Both, reparing and reinforcing. One of the lower links had a fracture at the
opening were the lower ball joint is pressed into. As it is obvious, that
the lower links are designed a little too weak, I intend to reinforce them a
little bit at the ball joint area and at the flanges.

> Also, weren't you the person that made contact with a urethane supplier
over there, and
> could get some of the suspension bushing parts made? I think that you
were going to wait to see if I was able to do
> anything here in the US. I haven't had much luck yet. Could you let me
know what is available to you in the area of
> urethane suspension bushings? Thanks. Keep in touch.

Yes, I am still in contact with the supplier "superflex". I have several
samples lying around. At the moment, we concentrate only on the bushing
"100154", which is used 10 times in the Delorean (8 for the rear suspension,
2 at the lower links of the front suspension). The samples I have will
definitely work for the rear suspension. But the front lower links are a
different thing. I am not convinced that the PU bushings can take the forces
at this special point, because they are designed differently than the
original ones. There is the danger that the bushing could slide from the
inner pipe, as the PU body is not bonded to the pipe.
As I don't want to risk any accidents, I will make a test mockup and measure
the force which is needed to press the mounted bush out of the lower link. I
will do this with an original bush (...ouch) and with the new PU ones. Then
we'll see, if they are capable. If the test results are not convincing, then
I will not give my o.k. for the use on the front suspension.

The bushes are not yet available, but they are listed on their homepage:
www.superflex.co.uk

Do you know the hardness of the original rubber bushes? Anyone? The PU
bushes are available in 70, 80 and 95. The samples I have are 95, and they
are much too hard! A simple test showed that they are at least 10 times
harder than the original ones. I don't want to increase the road noise and
the stress on the frame, so I tend to much softer bushings.

I will let you all know, as soon as they are available.

ciao,
Ralf
VIN10284