LCA design - Ideas and Opinions needed..

[naughtika]

fellas.. as most of you know, my LCA gave way and now I'm determined to replace it with something better..

someone here mentioned, 'why not just replace the ball joint with something better' it is a very good idea, but question is, how strong will that ball joint be? and also how long will it last? and to put it simply, it still is a ball joint..

so I thought why not replace the damn thing with a proper LCA.. not with a ball joint but with a rose joint..

I know the ball joint thread is 12mm, which in turn we use a 17mm nylock nut..

now, the idea I have is to replace the control arm with something like this..

View attachment 9486

and have the heim/rose joint installed upside down on the hub that way the control arm itself can move freely vertically and horizontally to about 20* each side - not that it will

also these will be added to the joint that way there's no resistance and possibility of dust getting in..

heim joint spacer (aluminum)

boot

at the moment these are just ideas, til i find out from what Bruce thinks about this idea..

so fellas, once again, I need your opinions and ideas so we can make this work

 

[naughtika]

also I've thought of using the aluminum spacers for the heim, so that if pivots too much I'll know due to the marks it make on the spacer..

 

[Nitephyre]

Looks good... and chunkier

 

[naughtika]

been reading a lot about rose joints and ball joints... trying to compare if what would happen if the ball joints were replaced with rose joints.. some say they cannot take that much load unless the proper size is used as well as how they're positioned..

I've ordered m14x1.5 Rose joints which is rated to handle static load of 65.8kN which equates to 6580kg..

fyi, I ordered the rose joints so that Bruce can tell me whether my idea will work or not..

 

[unclepaulie]

idea:

not sure if it would/could work, ill hav to suss out the clearances etc. But, the advatage is that the rose joint is supported from both sides

the I beam section is just an idea/for show too, it might need all the material there anyway, depends on the FEA.



EDIT:

scrap that idea.


EDIT:

this would be better (same as orange one)

 

[naughtika]

well this is the idea, I've got..

uses a m14x1.5 rose joint

 

[unclepaulie]

same same

 

[naughtika]

due to safety concerns that were pointed out to me, I'm not going ahead with this anymore..

 

[godzilla]

What concerns?

 

[naughtika]

the design itself, apparently there's possibilities that the alloy would not be able to hold the load.. so it's possible that it'll snap easily..

same goes to the rose joint, as the hardware itself isn't made for that purpose..

 

[Kenneth]

That is basically the conclusion I came to. Ok to do for yourself, but I would never share it as a good idea with anyone else in case there was a catastrophic failure.

After that, I started thinking about alternatives. The one I like best at present is to somehow relocate the pickup for the shock onto the actual hub carrier. The main issue will be allowing it to pivot correctly without fouling, however the result will be to totally unload the lower arm. Without that load on the lower arm, it is also likely that it could be reduced in size (weight) without any worry.

 

[rockit]

The one I like best at present is to somehow relocate the pickup for the shock onto the actual hub carrier. The main issue will be allowing it to pivot correctly without fouling, however the result will be to totally unload the lower arm. Without that load on the lower arm, it is also likely that it could be reduced in size (weight) without any worry.

I agree with that.. would involve a fair bit of work, and would possibly need different spring as you may require a new springrate to keep the wheel rates the same.

 

[steveP]

So the best solution is to just replace the stock item with a new one.

I've had this slight knocking sound when I go over a pot hole, or drive over bricks or similar at slow speed. Now I'm paranoid.

 

[unclepaulie]

So the best solution is to just replace the stock item with a new one.

I've had this slight knocking sound when I go over a pot hole, or drive over bricks or similar at slow speed. Now I'm paranoid.

steve, if you're super worried, put a little nick in the rubber boot and spray some lube in it, just make sure it is the good stuff that repels water. Then duct tape up to nick in the boot if it's big.

i think the reason they fail is due to lack of lubrication, they dont just explode. there would hav been a tablespoon worth of dust in the ball joint. the pictures tell the story




EDIT:
or if you're really worried, take them off, take the boot off and inspect them/regrease them

 

[Kenneth]

If there is a knocking, you need to inspect the joints for play. If there is ANY play, it needs to be replaced ASAP.

Of the failures I have known of, at least half of them were when the person KNEW the joint needed replacing and was just "taking it easy" while they waited for a replacement.

Paul is correct in saying that they don't just explode, in every case of failure I have heard of, there has been warning in form of noise. If you are getting noise and have play, then this is your warning and it could go at any time.

I just replaced the left hand LCA on my Galant, it had play in it but was still well greased and was not making any noticeable noise. Once it is making noise, it is a lottery to how long it is going to last. On average they do last a little while until total failure, but you never know.


The knocking could be something else, you need to have the ball joints checked for play to know for sure. If you want to check yourself but are not sure how, let me know and ill help.

 

[naughtika]

i strongly suggest that you avoid putting a hole on the rubber boot and fill it with grease, every time that the ball joint pivots.. the grease would wanna come out of that hole..

also just found out that we can buy rubber boots from mitsubishi.. part number is MB808555...


my plan now is to replace my current control arms once and for all.. then in 6 months time, will buy another set (4 pieces - straight and curves - LH & RH) and as well as several pieces of the rubber boots..

that way when I check the ball joints every year to see its condition and to re-grease it, I can replace it with new rubber boots..

trying to find out if who stocks MB808555 - in terms of aftermarket ones.. I haven't tried whiteline or fulcrum - will contact them soon and hopefully they can supply better sets..

and after searching several sites, there is a special tool to remove this spring that holds the rubber boot in place..

 

[Kenneth]

I would advise using OEM LCAs as they have a much better reliability record than non OEM. They are more expensive, but should last much longer under the same conditions.

It isn't just about lubrication, they will eventually wear and fail regardless. As per my post, I just replaced one which was still well greased because it had developed a small amount of play.

 

[unclepaulie]

side note: if we did ever do a group buy from mitsu japan. Jesse Streeters container is stored about 300m from my house, so i could go and collect them from there and post them out. might be cheaper than individual shipping.

 

[naughtika]

doing a group buy for the control arm's gonna hurt our pocket.. the overall weight of it will cost use a fortune when posted from Japan..

also just a reply to Kenneth,

I do fully understand that replacing the control arm is inevitable.. hence I mentioned to stock another set of control arms just for peace of mind..

but if we can extend the lifespan of these control arms, I think that's a plus..

 

[unclepaulie]

doing a group buy for the control arm's gonna hurt our pocket.. the overall weight of it will cost use a fortune when posted from Japan..

also just a reply to Kenneth,

I do fully understand that replacing the control arm is inevitable.. hence I mentioned to stock another set of control arms just for peace of mind..

but if we can extend the lifespan of these control arms, I think that's a plus..

wont be as bad if they're stuffed into a container thats already on its way here