Balljoint with slightly different taper - OK to use?

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Hi guys,

I have a Mitsubishi Mirage that I converted to a track car.

In an effort to raise the front roll center, I am looking for longer ball joints.
That is a MacPherson front strut and I want a longer lower ball joint that connects the upright to the lower control arm.

I have found one that fits all the criteria except that the taper is slightly off.

When I insert the tapered end into the upright it can wiggle by about 0.5mm.
When tightened there is of course no more wiggling.


Is this safe to use?
I can the issue being that there is in reality only a slight amount of metal on metal contact due to the slightly off taper but don't know how much of an issue this actually is.

I may consider getting either the ball joint or upright modified to suit one another if is an issue.
 
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Not good, but you could try filling the excess with something softer, like alu foil. As it is the load is all on the threaded part and the taper bears none.
 

Astro14

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Not good, but you could try filling the excess with something softer, like alu foil. As it is the load is all on the threaded part and the taper bears none.
I think the tapered portion of the balljoint is carrying all the load. The threads simply keep the taper tightly seated so that the load can be carried.

No way I would use this as is.

Ream the control arm to match, or find another control arm/ball joint so that they match.
 
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In an effort to raise the front roll center, I am looking for longer ball joints.
That is a MacPherson front strut and I want a longer lower ball joint that
connects the upright to the lower control arm.

That's generally a good idea, in particular if your car is lowered
(because lowering a car with McPherson struts will inevitably lower
the roll center of that axle commonly much more than the center
of gravity is lowered).


I have found one that fits all the criteria except that the taper is slightly off.
When I insert the tapered end into the upright it can wiggle by about 0.5mm.
When tightened there is of course no more wiggling. Is this safe to use?

I wouldn't use it and send it back. It has to be a perfect fit. No
trimming please! Remember due to the extended lever of this
longer balljoint forces are elevated anyway and that even more
so if you use dedicated track rubber. Don't take that risk please!
.
 
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I can't imagine using anything but exactly the correct part in a critical steering or suspension system. No filing, no aluminum foil, no wiggling. But maybe that's just me.

The balljoints seat in aluminium knuckles on several cars, what it needs is support which it doesn't have now
 
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I think the tapered portion of the balljoint is carrying all the load. The threads simply keep the taper tightly seated so that the load can be carried.

No way I would use this as is.

Ream the control arm to match, or find another control arm/ball joint so that they match.

The tapered part is carrying no load in his case as it doesn't fit. But it should bear the whole load.
 
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I saw in "Powerblock" of all places that you can get a tapered drill bit/ reamer to adapt knuckles for different ball joints.
You'd have to find the engineering drawings for your stock and proposed replacements to get the correct tool.
 

D60

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Tapered reamers common for TRE flips in the off road world. I'm guessing the ball joints are a different taper but it's worth looking for a tapered reamer.
 
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.
It isn't the job of the customer to trim suspension parts for fitment.
That's my understanding at least.
If they are that poor of a fitment I strongly question the design and
the quality control of that manufacturer. Why trust someone who
doesn't control the bascis? Why use suspension parts from someone
who you can't even trust? Some people seem to have a surprisingly
lowish approach.
.
 

D60

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.
It isn't the job of the customer to trim suspension parts for fitment.
That's my understanding at least.
If they are that poor of a fitment I strongly question the design and
the quality control of that manufacturer. Why trust someone who
doesn't control the bascis? Why use suspension parts from someone
who you can't even trust? Some people seem to have a surprisingly
lowish approach.
.
Um, burrito?

As I read it he's using an entirely different application. This is custom, or in this case mix 'n match hodgepodge

It isn't the responsibility of the manufacturer to guarantee that, say, their Subaru ball joint will fit a Mitsubishi. Example only, I have no idea what application(s) the OP is mixing
 
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The balljoints seat in aluminium knuckles on several cars, what it needs is support which it doesn't have now

Just curious, what cars? All tapered seats of aluminum swivels
I've seen so far were sitting in pressed-in steel inserts. So are
the ones of my GTI.

Schwenklager MQB GTI 5Q0407253A links 1M.jpg

Schwenklager MQB GTI 5Q0407254A rechts 2M.jpg

.
 

D60

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Just curious, what cars? All tapered seats of aluminum swivels
I've seen so far were sitting in pressed-in steel inserts. So are
the ones of my GTI.

View attachment 99481
View attachment 99482
.
That'd be sweet if this was the case and you could press out those seats, ie have new ones made and press in.

The only Al knuckles I have experience with are JL's but they're inverse: bj body presses into knuckle and the tapers are in the inner C (axlehousing) which is steel.
 
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