More LCA - Hotchkis problem ?

[morgan]

Chaps - me again. Yeah, I know. Sorry.

Quick sanity check please. I think these hotchkis pivot bushes are not right - will try my best to explain.

The shell get pressed into the LCA as normal, the 'inner' bush is a poly jobbie which is shaped like a mushroom or muffin-top. See pic for detail. This hasn't looked right to me from the off....

The problem comes that because of this (I think) the LCA does not sit far enough forward on the pivot. The net result is that the torsion bars don't go far enough forward either, and the struts at the front (the diagonals that bolt onto the LCA) cant bolt up either, they don't go far enough forward.
The problem can be clearly seen on the other LCA (still off the car) - the pivot doesn't go all the way into the bush - it cant, because of the muffin top.

I realize that is a really bad description. Basically "Does that bush look right to you? I think it needs the mushroom cutting off". This would allow the whole LCA (torsion bars, strut, the lot) to sit a 1cm forward and thus align properly. It really isn't much - less than a cm - but its a critical cm without which the assembly wont work.

A quick pic under your car would be good to see where the LCA meets the pivot. Its the one angle I don't have

[Pete]

Looks wrong to me - does not look seated suffiently deep.

I always use rubber LCA bushes as they are positively located and this issue does not arise.

I guess - If the bush is the correct one for your application - the issue is understanding why it sits so proud..........

[morgan]

I know - and then I find this - all sitting proud ?!? Don't know what to think now. Will extract poly and check the shop pressed shell deep enough - seems a good starting point. (tomorrow that is)

[Pete]

Might be ok then, just need to measure up.....

[morgan]

I aint getting this.

Google search on lower control arm bushes. First 2 pics show the problem.

The one on the left is what I have (and seemingly all poly bushes look like this). The one on the right is a stock LCA bush from yearone.
Clearly they are not going to locate the LCA in the same place - The stock item will allow it to sit closer to the k-frame.

I have a set of stock bushes. If the hotchkis pivots fit them then I think I might press the poly out and start over. I cant help but feel I am missing something though ? They cant be wrong - why would they all be made like that ??

[Pete]

Measure from the surface of the LCA to the Top side of the Pin where it contacts the "K" Frame.

If the distance is the same as a stock one (Someone may be able to measure one for you - I will try later - in milimitres) then you know what is going on..............

[Dave-R]

The images are not cear enough to see well but it looks to me as if the poly bush has not been installed correcly into the LCA.

Did someone do this for you?

I think they have knacked the bush.

[Dave-R]

There is a knack to installing these bushes. From memory (errr...) I think you have to install the bush in the arm first. Then press the pivot in. If you put the bush on the pivot first and then try to press the bush in it f's up.

[Pete]

Also, check the pin lengths against the originals to see if there is something amis there......process of elimination....

[morgan]

Yeah, more research tonight.

Few quick answers -
- Yes, bush pressed by local autoshop. I was there. Shell first, poly second, pivot last.
- Poly insert comes out OK (bit of pulling) so will check shell is all the way in.
- I have the old pivots etc. Will do a compare later.

As you say Pete, process of elimination.
Measuring of LCA to k-Frame would be really useful info - thanks !
Better pics later.

[Pete]

I can't get a measure in the space dueto t he shape of the "K" but I have taken some photos - will up-load later.

Pete

[Adrian Worman]

It seems likely that the outer sleeve of the old bush has been damaged at the front end when it was pressed into the lca, any nicks or creases will stop the poly from seating.
I don.t usually take them out when I do that, just burn the inner sleeve and rubber away with a torch and carefully clean up the inside of the remaining sleeve.
Take it apart again, if necessary get some new lca bushes, I would suggest tho that you stick with high perf poly bushes as you.re using much stiffer torsion bars, the std rubber ones won.t cope so well with the increased spring rate

[Pete]

Here are the pics, don't help a lot, I'm afraid....

[morgan]

Actually Pete, thats pretty helpful. there *is* a gap between bush and pivot, which implies it doesnt need to 'butt right up'. Which in turn means that if the poly seats right, the muffin-top should just sit on that gap. My muffin-top must be too proud.

Not sure what stops your LCAs moving forward though ? Must be the shaft butts right up to the torsion bar inside the LCA. (which would seem logical) Pic (A)

Either way - what you have shown me gives a good lead. I do appreciate it.



Pic (B) shows the root of my issue I believe. That shaft should be flush to that torsion bar mount. Need to discover why it aint. Much measuring and compare first.

[Pete]

.....Not sure what stops your LCAs moving forward though ? Must be the shaft butts right up to the torsion bar inside the LCA. (which would seem logical) Pic (A)

...Which is why I don't like Poly bushes.

People will disagree with me, BUT I found the LCA moved back and forward in the S&M Barracuda with Poly bushes. There is nothing mechanical to stop the movement. I solved it (badly) by shimming the Torsion Bar so there was no movement fore and aft. You should not really do anything that loads the Torsion bar circlip in my opinion........