I changed the front ball joints to my car as i had installed a grease fitting to another pair of ball joints i had and wanted to do the same for the pair that was on the car. I noticed that the two pairs i had were completely different in every way. The other pair was a steel casting with threads in the flange. I haven't found any markings of manufacturer from these. The other pair has a steele body with the ball joint obviously pressed into it. These had VW logos stamped inside the cavity where the strut tower fits into.
The cast-steele ball joints (ones with the threads in the flange) feel much more stiffer than the other brand. I didn't find any play from any of the ball joints but still the other pair was obviously much more stiffer.
You can see the obvious differences in these pictures i took. 'Full steele casted' type on the left and the 'pressed on' type on the right:
I've seen yet another type of ball joints with welded-on fastenign nuts. If i was buying new ball joints and had the possibility to choose between these three different pairs, i'd go for the full cast steele bodied ball joints.
The ones with the pressed in cap.....are early. In gneral they are equal to the later ones. They both have cast steel bodies. The early ones with teh cap are simply loaded in from the cavity side and have the lid swaged on from the inside. The later ones have the parts loaded in from the ouutside and have the outer lip swaged to keep the parts in against the spring.
Parts and spring wise they are identical on the inside. The one with the cap on the inside simply "feels" smoother and moves easier because the outer seat or lip that the ball rides against is smoother than the one that is swaged at the outer lip.
The one with the cap...tends to last a little longer...without grease. The later one tends to wear a little harder on the ball and lip. keeping them greased seems to alleviate most of this.
The test to see if one really is weaker...is to put them in a spring tester with a dial gauge like you sue for valve springs and compress teh stud until you see movement and read the psi. You will gnerally find that they are the same. You can also drill the grease hole right into the center of the cap just like on the later all cast one.
The aftermarket ones I have seen pictures of.....but never used. Personally on those aftermarket ones.....I would make a three hole support ring for underneath the bolt flange and use longer bolts. Ray
i just took a closer look at the ball joints that came off my car and they're a mismatched pair; although identical from the outside (including fully threaded holes), there are a few differences under the boot and inside the cavity:
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the joint on the right (with the pressed-in cap on the inside) is considerably easier to turn...i can do it by hand no problem, in all directions. the other one wont budge. i can get it to rotate a little by gripping the flats on the stud with pliers, but thats it. i didnt check them on the car before i pulled everything off, so i tried to fake it by putting them on my drill press table and using the wheel to send the chuck down onto the stud and feeling for play. the free-turning one has i would guess 1mm or less, the other i couldnt feel any.
it makes sense to me for them to be matched, at least in terms of friction...opinions? i did find a spare set in a bin (late-type), but they're even harder to turn. anyone ever pulled outside cap off and serviced the insides?
Being really stiff is just fine, it shouldn't cause any problems and should give the tightest possible suspension. Having two joints that were exactly match would be nice, but it shouldn't cause a problem having two by different manufacturers. There must have been at one time at 5 or more different companies making these as evident from the slight changes in design. The ones with the welded on nuts are the only ones that I know of that can be bought new these days, but they tend to bend and should be avoided if possible.
Yep...I agree with that. I have used matched and mismatched pairs of both types. It will make no difference in driving.
The only thing to watch for is if the spring pressures are greatly off. The springs can get weak with age...and typically...this is also the failure point. Damaged struts...or struts that are frozen or too stiff...transfer the compressive load to the ball joint springs ...over compressing them and either weakening or cracking the springs inside.
The reason teh sealed type ball joint is stiffer..is partly because the lower seat flange that the ball rides against is rougher because it is the part that was machined swaged. The "capped" joint has a machined lower ball flange that is smoother because its loaded in from the other end. I have been inside both of them.
As long as one is not noticably weaker of spring there will be no difference.
The aftermarket ball joint with the welded nuts...I woudl grind off teh nuts and make a 3/8" thick traiangular flange of good steel with threads in it to come up fron the backside. Ray
