In a message dated 5/5/2006 8:11:20 AM Central Standard Time,
spamiam@comcast.net writes:
> That are the thoughts on tube shock conversions for a TR4A? As far as I
> can tell there are 3 types.
>
> 1) The conversion which bolts the upper end of the shock to the inner
> fender.
Run, don't walk, away from this one. The fenders are not designed to take
this loading and will suffer for it. These conversions should all be rounded
up
and set ablaze!
There is a modification to this type that includes two other pieces (per
side) that bolt to each other eventually transferring this force to the
original
shock mount. If you want to drill 16 largish holes in your car you may
consider these as acceptable.
>
> 2) An adapter bracket which bolts to the original lever shock mounting and
> holds the top of the new shock.
This is what I have. My only qualm is that the shocks are a bit too short
for my new competition springs that returned the car's ride height to original
specs - for the 76 model. But they work well and don't foul my tires.
>
> 3) A coil-over type. Apparently TRF has a few of these on hand but says
> they are "expensive".
Grunt, grunt, grunt. I want. I want. They may not be all that much more
expensive but the ones I've seen require some machining, and possibly, welding.
Not a bolt in like #2.
>
> So, what is the best way. I bet option #3 is more expensive that I would
> like.
>
> I prefer #2 because it is completely reversible. But, I have heard that the
> tube shock itself becomes the stop at full downward travel of the trailing
> arm.
This is true for the front suspension. And just about any other suspension
system with tube shocks. Only the TR2-3 (and possible the TR4) front
suspensions are the only one's I've seen with an external down travel stop.
The lever shock has a stop on the lever arm itself. I saw something on the
> internet saying that this off-center torque will make the frame fail.
Why? Is this force more that that exerted by the shocks during severe
suspension travel episodes? I don't think so. Unless the shock is shot.
DOes this actually happen in real usage? I would think that maximum downward
> travel would be relatively rare.
As referenced above, my car reaches the end frequently. It's ride is more
like a TR3 in that regard. No detrimental effects so far (but I don't have too
many miles on it yet, only about 1000 or so.
>
> The, the torque from the off-center upward force is probably much the same
> for both the original lever arm and #2, but I have not analyzed the geometry
> of #2 since I have not seen one personally.
I haven't thought about it much seriously but since the two end points are
the same it should lead the frame the same.
Dave Massey
57 TR3
71 TR6
80 TR8
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