Redid Front End, Alignment Questions

[mpost3r]

Hi all,

So we recently did the Meyle HD ball joint upgrade on my friend's 325i. First of all, I don't know why people say you can't replace the ball joints in these cars. It's just like any other control arm. You take the arm out, take the lollipop off, cut the tabs for the stock outer ball joints, and press both of them out. Simple as that.

Anyways, we put those new ball joints in, and put Garagistic 80a centered lower control arm lollipop bushings in. This is what we went with:


outer:https://www.fcpeuro.com/products/bmw...-31126758510my
inner:https://www.fcpeuro.com/products/bmw...-31121139131my
bushing:https://www.garagistic.com/products/...3f423416&_ss=r

All a direct replacement. Wax on, wax off. This is where my questions begin. The car drove fine before installing these parts, but the ball joints clunked like hell and were so torn and flopped around. After replacing them, there is no clunking to be heard, but the car pulls aggressively to one side(i forget which, and don't think it matters). While I've done a few alignments at the shop I work at, I'm still not sure as to exactly what can happen. And yes, we did line up the notches on the inner ball joints correctly.

Do you need an alignment after replacing these ball joints with heavier duty ones, as well as a poly control arm bushing setup? It should also be noted that the alignment was knocked off on the previous set of ball joints, so I'm afraid that the alignment was done when the original ball joints were already failed.

If not, is there any other signs to look for? He also put new koni and h&r shock and springs on it AFTER the old alignment was already done, so is that about all there is to it? I'm just trying to figure out why this would have thrown off the alignment this much. We're going in to double check our work later, but I'm going to do this to my car soon as well, and I'd like to completely know before I get into a position where it drives even worse than it did previously.

Thanks!

[spyderg0d]

Anytime you replace any suspension componant with the exception of sway links, there will be an alignment change.. Especially with sagged in knocking ball joints.. If a ball joint is bad, it has slop.. That slop allows the tire to sit in that sloppy positioning alignment.. Now that you replaced the joint.. Theres no slop. And thus the wheel is moved to the correct spot.. And... Youl need a new alihnment.. Thats kind of a no brainer.
This goes with any bushing, or bearing, or arm, joint, strut, spring ect... I suggest you learn more about how suspension systems work before doing anything on anyones vehicle without proper insurance.
Suspensions can be difficult to understand but should be learned before throwing parts at it. Every piece in a moving system effects all the other pieces and changes variables.

[mpost3r]

yes. it was a friend's car that both me and him worked on. I was aware of that, and understand that there are numerous forces that are applied to it, which is why I mentioned that I was afraid the alignment was done on the failed ball joints. I'm not the designated alignment guy at the shop, either; it's more of a "let him watch us and we'll have him turn wrenches as we explain to him what that's doing" kinda deal. If I had my own alignment rack I could dial this in as I do have a relatively firm understanding in the suspension geometry of an e36, but not necessarily every car. Perhaps you could jot down a force diagram on every joint and bushing, etc, and figure out how much force goes where, but that's a lot of vector calculus that I'll leave up to the alignment machine's computer and the simulations the engineers run. Plus, variables change almost all the time, up to whether or not you have a passenger in the car, etc. (that's actually why I got an e36 2 years ago. I have a ton of respect for all the thought that was put into dialing these things down).

Basically it was just a confirmation--like a "okay, I am on the right thought process" kinda deal. I'm just unsure of what exactly an 80a poly control arm bushing would do. It's not offset, because if it was, my brain is telling me that would slightly alter the caster--I'll have to go fact check that one, but the ones we pulled out were centered, so the new ones are centered too. Perhaps the stiffer-than-stock poly control arm bushing would prevent lateral movement of the control arm, as it's gonna be stiffer rocking back and forth on that lollipop.

I just can't think of many other things that could throw the alignment off THIS much. I knew changing suspension and ball joints and control arm bushings would alter the alignment, but not to the point where the steering wheel is almost a quarter rotation to the right. That seems excessive to me. We're going back under tomorrow to check out the shims on the struts and to double check the work done.

On that note, I'm working on dialing in the alignment specs that I want for the car. Which means..... Rear ball joints and RTABs need to be replaced too, because they're too worn!

[spyderg0d]

Your ahead of yourself already.

[gdavid]

I would set the toe-in with a piece of string strung down the tires on each side to get a rough alignment until you finish going through the rear suspension. The track width is 1/2" wider in the rear, assuming you have stock wheels, you can get the front toe pretty darn close to spec by just setting the wheel straight and adjusting the tie rods until the string is touching the front and rear of the front tire when pulled taught and in line with the rear tire.

If either of the rear trailing arm bushing are bad, it will really throw off the rear toe and make it pull hard. It is a good idea to replace these at an absolute minimum prior to getting an alignment. Even when they appear to be solid, if they are original, they are old and likely to fail once the car is getting some miles put on it.

[XnWarden]

Yeah honestly what are you even talking about? Just check the toe and set it. End of story. No need to type an entire essay.

Sent from my SM-G975U using Tapatalk

[mpost3r]

okay, thats the plan. cheers!

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how so?