Front beam Spring Pack question

[Keith Lawrence]

OK - I'm in the process of putting my front suspension together after a crack test and cleaning and I have found that the turkey leg on the left side rotates about 2 inches on (more accurately "around") the spring leaves before it "catches" or engages enough to get spring effect.

On the right hand side, the spring pack went into the turkey firmly and held well even before tightening the allen screw.

My spring pack had 4 wide leaves in the center and 2 half leaves; one half leave each on the top and one on the bottom.

So I'm thinking that the leaves on the left side are too much like an oval and/or the turkey leg square hole on that side may be a little worn.

Can I just add some type of shim to take up some of the space that the half leave misses in order to get the spring pack to be more "square shaped"? Or am I missing something altogether.

I have not tried to tighten the allen screw to take up the different, as I'm afraid in racing situations that this may not hold it tight for long.

Advice welcome.

Thanks
Keith Lawrence
Pittsburgh PA
1964 AutoDynamic

[FV80]

Keith,
I'd say something is WRONG with your assembly. Take it back apart and I'm pretty sure you'll find that not all pieces of the spring pack are inside the left turkey leg. The ends of the springs don't get 'rounded' (too hard) and the inside of the turkey leg won't get 'ovaled' unless you leave it loose and race it that way for about a YEAR .

You should be able to look inside the square opening on the left side and see that there is SPACE where there should be SPRING .. (compare it to the right side).

BTW - you only have to take apart the left side to see what's up - but fixing it might require a new spring pack (or pieces thereof).
Steve

[FV55inSpokane]

Sometimes I've cut pieces off of the ends of the leaves and glued or taped them into place to act as spacers to fill in the empty areas of the pack. (sides and center need to have full packs in those areas)
Maybe yours was that way but some of them slipped out of position.
Lawrence

[Dietmar]

Keith:

The way I read this is that you have 4 whole leafs ( leaves) and 2 half leafs in your stack- 4 wholes in the middle and 1 half on the top and 1 half on the bottom. If we counted blades you would have 6. Correct me if this is not what you have. If this is so, that is why the arm wants to rotate without picking up the ends of the springs.

You SHOULD have a total of 8 leafs(blades) to start with. 4 whole and 2 SETS of half leafs.What you do to them after that is up to the individual set up. Some cut leafs, some remove leafs and weld pieces back in, some replace halfs with whole leafs.
Bottom line ( as Lawrene said) is that you need 4 whole and 4 halfs on the ends and in the middle.

If you do have the 8 blades total on the ends, and still have the problem, then I would do as Steve suggests and measure the square in the end of the arm and see if it truly is still square. Someone may have "modified" the end.
Hope this helps
Dietmar

[Keith Lawrence]

Lawrence and Dietmar,

Thanks. I think you have answered my questions. I will look closely tonight when I get home, but on the left side I'm sure I only have 6 leaves (4 whole in the middle of the stack and 2 halfs on the end).

On the RH (good) side, I think the half leaves are wider - I think someone welded in a spacer to make it more of a full leaf, but just at the turkey leg end.

On the LH (bad) side, I think a spacer may be missing. Should be easy to fab up an insert and I like the idea of tack welding the exposed end to ensure it stays in place.

This car has sat for many years before I got it and was most likely never raced since the previous onwers last took it apart.

I'm also going to do some more research on this wesbite to see if I should not try running with the 4 whole leaves and 4 half leaves (instead of the current 2 half set-up). It seems like someone thought the 6 leaf set-up was correct when they last raced my car and I have no open wheel car handling experince (YET!!!).

THANKS!!!
Keith

[FV80]

Keith,
You shouldn't have to put it on the track to find out. It's all about holding the car at the right level and if it does that, then you should be OK. You want the Turkey legs to be "about" level with you in the car - and it should move up and down more or less freely (no shocks for this test). Whatever works on your car should be correct. The only other issue is the spring RATE - controlled by the number of split/cut leaves in the pack. In the old days, most just BENT the entire pack (not an easy task) and therefore retained the spring RATE of the entire pack. It might be better to cut/modify the pack (now legal in the rules) to change the RATE of the spring (as it appears, has been done with yours). Adjustable centers are now also legal and can be set so that the car rests at the appropriate height (but you have to cut the beam and weld it in).
Steve