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3-Bolt Ball-Joint Versions and related info... a more definitive guide.

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  • #16
    Originally posted by M2ki View Post
    Okay, maybe these audi wishbones are forged.
    But cast iron wishbones are still used and made every day and they will not snap in 5 minutes like error404 claimed.
    you can ask this company: https://lightweighting.co/market-research/
    and find out about the cast iron LCA
    sigpic

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    • #17
      If you have some info on this topic, you can share it here, others will also appreciate it.
      I'm not gonna bother some company with my stupid questions.
      1989 Audi 80 Quattro
      1994 Audi 80 Quattro Competition

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      • #18
        Common sense of what should I use to translate word 'Gusseisen' to English?

        guss.JPG

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        • #19
          Seriously, you guys are really arguing about this over the wording in ETKA?

          You can see they are forged with your eyes - the big wide flash trim lines down the side give it away. Casting leave a very thin flash trim line.
          Panthero Coupé quattro 20vt
          Indigo ABY coupé
          Imola B6 S4 Avant

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          • #20
            Bingo, thanks for pointing that out (the trim-lines feature) sir. Error is exactly right. For those less familiar, what he is referring to, is that looking at our very likely forged A-arm that is laying flat, all along the sides of the arm one can see and feel how rough finished the steel is, as opposed to the smooth top and bottom surfaces. These side areas appear to have been ground just quickly with a hand-held abrasive wheeled tool. The width of that ground area (or more accurately it's height) is quite wide, wider than what one would find along the part lines of a cast part, as casting moulds are made to meet and mate more perfectly almost everywhere leaving a very narrow flash gap, whereas with forging dies, in order to have an effective hammer-blow, the perhaps only semi-molten metal has to be given a more generous area to be squeezed to, hence the wider areas needing trimming after being die-struck.

            Many other folk have long had this same question: "Is thing X cast or forged?" particularly when one can't have witnessed the original process, but require a definitive answer. Some myths and other determinative methods are discussed here:

            https://forum.millerwelds.com/forum/...way-to-weld-it

            https://weldingweb.com/showthread.ph...-forged-or-not

            Photo below shows in its' center, a cast crank's necessarily narrow mould horizontal part-line lined up against a forged one's wanted wider part-line:

            The tell-tales of two cranks.png

            Quite interesting all of that. However, from my perspective, particularly as there isn't much we can do about how the arms where made, the most significant thing is that, all of the advantages fall in favour of the likely forged arms, and in particular that they allow us to then employ the larger diameter OEM bushings they require vs. the earlier small ones. The proper care and feeding of those bigger OEM bushes alone will have as great or greater benefit to your driving pleasure every day; than whatever A-arms you may have. What I consider proper (in terms of cost, durability and steering response) is simply the use of these (link below) along with new OEM bushes:

            Arm-Stops

            All right then, if there are no more questions, eventually this OP would like to next steer the conversation back towards ball-joints if you don't mind?
            Last edited by Lago Blue; 31 December 2020, 03:48.

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            • #21
              A few thoughts and questions I had while writing the above:

              - It appears that the "B4" ball-joints where part of the B3 to B4 wheelbase lengthening component changes that also saw the front fender-arch move forward on the later cars;

              - It may be that the later ball-joints (for forged arms) with the raised ball position, were made simply to maintain the original (with pressed style arms) clearances (under the CV's and A/R bar?) above the arm's topside (photos below hints at how close ball-joints for pressed arms, mounted on forged ones; makes things):

              Forged arms & ball-joints for pressed arms close-up.pngForged arms & ball-joints for pressed arms RH side.pngForged arms & ball-joints for pressed arms LH.pngAndrey Puzakov's photos and interesting bushings

              - It may not be of any immediate consequence if one was to as above, use ball-joints made for welded arms; on the forged arms, simply closer particularly on full extension I'd guess (watch your fingers!), but the reverse (pressed arms with ball-joints for forged arms) may not normally be entirely do-able due to the presence of the buttressing on the later ball-joints, which might interfere with the pressed arms joint receiver plates (however as per photo below, it can be done);

              Pressed arms & ball-joints for forged arms.png NailTim's pressed arm mod photo

              - Question: The spacer-plates (item 5 in the ETKA illustration up-thread and in photos above) "under" the nuts, appear to be specifically for use with the plain lock-nuts (vice the later serrated ones), rather than a particular A-arm or stud, what is their purpose and/or how do they function?


              - Looking at the photo below, one can see how a less offset ball-joint (as the ball is moved towards the front of the car, towards the left in photo) will increase the caster angle, and due to that increased top-mount to ball-joint ball axis fore-aft tilt (which provides the caster angle), also increases the mechanical trail distance; ever so slightly;

              S2 hub ball-joint receiver offset.pngG60Rallye's S2 RH hub photo

              - Perhaps counter-intuitively, the analogous bearing to the ball-joint, on a bicycle's head-stock for example, would be the bike's more lightly loaded upper bearing, each carrying strictly lateral loads and zero vertical loads (unless one employs the early style A/R bar drop-links which connect to the A-arms*);

              - So the job description for the ball-joints would include, holding the strut base steady in position laterally, allow both suspension and steering to pivot, and transmit mostly horizontal loads*. It will therefore most likely first exhibit play front to rear and/or sideways.

              - Despite that unlike top-mounts, they aren't constantly carrying the vehicle's weight, but by sitting so close to the axle, closest to the cross-roads of braking, cornering and accel. forces (aka the wheel bearing?), they must transmit the largest of the lateral loads to the chassis and also help to precisely define front-end geometry, and being so small, they ought to be the joints that wear out the fastest, not the top-mounts!

              - Question: Is the forward offset of the B3 Coupe hubs' ball-joint receiver (seen in photo above) the same as the B4's?

              - Use of the later less offset ball-joints will also alter the Ackermann slightly (by effectively moving the rack aft), a small increase in its effect;

              - The above to say that, when cornering, the toe-out of an inside wheel increases as the included angle between the steering arm and the track rod is made smaller, as it would be by moving the strut-bases forward;

              see Dale Thompson's remarks re "move the steering rack rearward" on page 9 here:

              https://www.me.ua.edu/me364/PDF/Steering_Ackerman.pdf

              - The sum of these very small changes may help to explain any differences one might feel in steering two cars so equipped;

              - Citing the above possible effects, the obfuscation of various parts listings, and there being two near identical joint types (with both the raised ball position and the buttressing ridges), it would be easy (particularly for a garage!) to miss that your two ball-joints are not of the same offset.


              Audi B3 & 4 ball-joints 2019-05-23 2 at 21.20.58.png

              However, when it comes to achieving most effective ball-joint function, and even including the side discussion which hinted at the possible resilience of different A-arms, knowing all the above is but about half of it. To be continued...
              Last edited by Lago Blue; 21 February 2021, 17:48.

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              • #22
                Back-stopping your ball-joints.

                No discussion of ball-joints would be complete without an examination of how well they are hinged to the car. This is important because it is only through the A-arms' inner connections that any fore / aft ball-joint station-holding ability (the steadfastness of which is critical to sending and receiving pure steering signal) can be achieved. By fore / aft, what is meant here is, relative to the long front to rear axis of the car, the prevention of any front to rear sliding movement of the A-arms, along the hinge axis of each A-arm's inner connections to the sub-frame.

                That connection needs to be, as far as possible, just as strong, slack-free and precise as the ball-joints themselves, otherwise the effective accuracy with which those ball-joints can guide (or be driven by) the tires' contact patches will only be as tight as the looseness of that total inner hinge connection to the chassis. It is precisely because that primary A-arm hinge-line is much more easily degraded than the ball-joint itself, that ball-joint effectiveness while underway; is most often wholly contingent upon the tired condition of that hinge.

                What this will briefly speak to (as I have written of this at length elsewhere) is the A-arms' connection to the sub-frame. The sub-frame's other larger four sub-frame to body bushings which I view as, similar to OEM top-mounts, necessary filters, I will not address here further.

                Because of the inherent vulnerability of the stock installation, new OEM A-arm bushings perish quickly and will allow random fore / aft ball-joint mobility on a scale nearer to the pin offset difference between the two (of three) ball-joint types seen above (it may approach the thickness of the end of your little finger). This (until addressed) makes much discussion of A-arm construction moot, except to say that forged arms hold paint better and to repeat, require the larger bushings whose increased joint volume contribute greatly to achieving stronger and more durable A-arm hinge-lines. Even poly bushes used here may eventually disappoint. These oft neglected OEM metal-lastic hinges will, with simple assembly differences, reward those who choose to not simply dismiss what OEM bushings can provide; and who attend to this deficiency. This mod will subtract slack and random vagueness out of your steering linkage. One of the reasons this mod is so effective is that the two wheels are then made to more closely point in concert and work; as one. This mod is, IMHO often the missing other half of understanding and achieving proper ball-joint function and will do much to both preserve the A-arms' bushings (otherwise they're sadly replaced for naught) and improve the steering character of your car.

                Link to: Arm-Stops

                On another forum I read that a rally UrQ owner was asked, at perhaps a US event nearer their east coast IIRC, the function of the factory heim-jointed trailing links (photo below) and was told they were to help preserve both the A-arms and the bushings. Whether it was that arm-trunnion cracking, similar to what one may have heard sometimes occurs to stock pressed-arms (perhaps originally designed to carry the earlier OEM double-ended push-thru type bushings) when used with nylon or similar more rigid bushings, may have been taking place to these also welded tubular arms and/or perhaps bushing/joint damage as axial loading (loads parallel to and felt along their mounting bolts) is their weak flank, no matter. The point being the factory clearly recognized the need to address the cause of this issue, that the stock arm-hinge design was axially weak. On our street cars, we may wish to not have to employ such complex measures, but without any counter-measures, what is left of your stock bushes, restraining your arms from fore-aft movement; if much at all? This contends even your newly installed bushings are already lacking in this necessary ability.

                Audi S1 rally subframe with arms & long-links.png

                From under your car, one can get some idea of how far your ball-joints will wander under accel. and braking by levering your A-arms forwards and backwards in their mountings. Underway, your car will move them more, more often, more easily, faster and more violently than you can, but also individually, alternatively and unpredictably as you can well imagine. Each wheels' compass heading is individually changing course with every A-arm fore-aft shift and shuffle. It is also quite easily and economically fixable.
                Last edited by Lago Blue; 16 July 2019, 16:34.

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                • #23
                  From the Factory Service Training Manual for the early 20v 7A Coupe which lists new caster detail and other changes (including S/S A-arms!) between this car and the earlier 10v 90Q):

                  Audi 7A 20V Fctry. Srvc. Trg. Man. Fr. Susp. detail changes.png

                  Also from the above manual, the illustration below, ostensibly to demonstrate the factory tool in use to make fine camber adjustments on the 3-bolt ball-joints more easily, also details an early style A/R bar connected to a forged A-arm, something that never was done in regular production, and which contravenes the official factory warning to not mix early and late suspension components! However, this is exactly what I did on my car.

                  Audi 20V Coupe, Late Type Ball Joint Tool.png
                  Last edited by Lago Blue; 31 December 2020, 04:26.

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                  • #24
                    Stainless steel?? Is this another translation anomoly? Interesting information over the caster change but I'm not sure anyone will ever claim to have rust resistant front wishbones on their car!

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                    • #25
                      Regarding stainless steel, that would be my guess, but you just never know what someone may find. Considering that S/S usually yields to bending more easily, It is perhaps an unlikely choice. However, if such did exist, that there were at least 4 versions of forged A-arms to quickly follow these would have eclipsed that idea in any case.

                      What I think that description corroborates is that both the early (for pressed-arms) and late (for forged-arms) Coupe ball-joints, each with their respective arms, likely share exactly the same effective offset for increased caster, mechanical trail and wheelbase, vs the 1989 Q saloon, the later joints simply being a raised ball version.

                      Perhaps of greater significance for us today is that although the altered ball-joints evidence the importance with which Audi regarded the necessity of this change for "good stability", and the decision was made to nearly double the caster measurement, this is still a very small physical change; and yet, save for the welcome huge net bushing volume increase that finally came with the 2nd forged-arm versions, not enough attention was paid to how axially limp the inner A-arm bushes still quickly became, which soon undoes much if not all of the increased caster sought by the altered ball-joints in the first place! Further, this allows the geometry to be rather random, variable and each side can do its' own thing independent of what the other side is doing! Given OEM bushes, that one may likely have parts effectively in the steering linkage, so worn that their slop is of the same order of magnitude as a factory part who's purpose contributes to the change of the listed wheelbase of the car; has got to be a compelling reason to want to fix it! While one cannot say it was done this way to ensure ample dealer service work, as most folks don't even notice the degradation, however everyone who has done the mod notices after a car has gotten Arm-Stops.
                      Last edited by Lago Blue; 22 February 2021, 01:24.

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                      • #26
                        More notes on P/Ns, description and photos for the forged-arm ball-joints (and fasteners) to replicate the factory update which increased caster.

                        Perhaps part of the possible confusion around which joints to get to achieve this change, is because at least in Europe, apparently early S2's may have 1st appeared with the forged A-arms and the subject joints, and then later on had pressed arms and different joints as delivered. Further confounding arises as one is presented with various alternates and miss-labelled parts when one searches them out. This aims to clarify exactly which ball-joints are required to achieve this near caster doubling when also using forged arms, the way the factory did it, as:

                        a) This is the path most worthwhile following, for reasons already discussed above, that and
                        b) I have no experience to tell me if the late S2 pressed arms (and their appropriate joints) achieve similar results (although given the factory description in the 1st (factory) drwg. in post #23 above, I suspect they must).

                        Since we are largely referencing front-end parts, perhaps it needs to be said that these parts where part of a group of B4Q type parts that altered the fore/aft positions (and the track) of both the front and rear wheels of the Q-sedans; and changed the factory listed wheelbase of those subsequent cars by lengthening it slightly at both ends. The front end parts that ought to all be used together to achieve the new 2°+ of caster are:

                        a) Forged A-arms, there are several (4?) versions, perhaps the later the better (if looking for these used, think any V6 FWD or Q, and cabrio), I have no idea if the very earliest forged arm versions all present the same fore/aft placement of their installed 3-bolt ball-joints, but they just might, as there was only ever one front fender-arch position for the coupes;

                        b) 3-bolt Ball-joints P/N's 895407366A (the RH); and 895407365A (the LH: pictured below). Knurled on top-side, smooth on the bottom. The socket which secures the ball is (compared to type 89's) both raised, and bracketed on both sides on the top-side by sloping buttresses. Perhaps the key feature is that the center of the joint's pin is nigh on perfectly aligned with the center-line axis of the most forward joint to arm attachment slot (as drawn in 2nd photo below); and

                        c) To review, the attaching together of the above two parts was changed (via factory technical bulletin) to best be done with 3 each of these two graded M10 fasteners:

                        - Stud P/N: 893407745A This is a pressed in (from the top-side of the arm - see arm photo below) 'bolt' that is an interference fit into the arm-hole, it has a fatter splined shank above the threaded portion. It is almost exactly like a vintage 911 wheel-hub stud only in miniature, if you are familiar with those. It was normally supplied installed with new arms. If re-installing, you may want to try to line up on the previous spline 'grooves' in the arm-holes if visible. I did find a great photo of Mance's (2nd last below) that clearly shows this is a class 10.9 fastener; and the mating nut you use should be as good so that (considering the lateral loads this area sees), the required torque will 'stick'.
                        - Nut P/N: N90285602 This is the proper serrated-flange all-metal lock-nut (NLA and hard to find), a photo of this nut's underside is back in the 1st post of this thread, a 'top-side' photo below. See also no. 7a in the 7Zap link below:

                        https://audi.7zap.com/en/rdw/audi+80...407-407010/#7A

                        Ball-joint 895 407 365 A for LH arm 1 of 5 Screen Shot 2021-02-21 at 14.05.44.png Ball-joint 895 407 365 A for LH arm 2 of 5 Screen Shot 2021-02-21 at 14.06.19.png Ball-joint 895 407 365 A for LH arm 3 of 5 Screen Shot 2021-02-21 at 14.05.59.png Ball-joint 895 407 365 A for LH arm 4 of 5 Screen Shot 2021-02-21 at 14.06.35.png Ball-joint 895 407 365 A for LH arm 5 of 5 Screen Shot 2021-02-21 at 14.07.17.png A-arm studs press in from top of arm and head lettering Screen Shot 2021-02-21 at 14.12.31.png A-arm stud head lettering Screen Shot 2021-02-21 at 18.01.39.png A-arm stud heads 10-9 visible Mance-s photo blow-up Screen Shot 2021-02-22 at 12.54.07.png Forged A-arm to ball-joint nut 2 Screen Shot 2021-02-21 at 15.42.33.png
                        Last edited by Lago Blue; 22 February 2021, 19:52.

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                        • #27
                          Im not sure if I understand your post, maybe I got lost...

                          There is only 1 forged control arm (893407147D)
                          B3 late CQ/90 had it just like the B4 cabriolet and 90 (in the USA)
                          Ball joints have different offset.

                          (I have the forged control arms on the rear of my B3 90q)
                          Attached Files
                          sigpic

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                          • #28
                            Originally posted by varia View Post
                            There is only 1 forged control arm (893407147D)
                            Early ones are much thicker.



                            Originally posted by varia View Post

                            (I have the forged control arms on the rear of my B3 90q)
                            How? With what ball joints? Pics?

                            1989 Audi 80 Quattro
                            1994 Audi 80 Quattro Competition

                            Comment


                            • #29
                              Dustin,

                              A 3rd version (LH arm in 1st photo below) of the forged arms appears to be almost identical to the skinny one above, but does not have the two little triangular 'ears' on the inboard circumference of the trunnions which hold the bushes (when present (see RH arm in 2nd photo), these 'ears' appear to aid bushing removal). So the trunnions look identical to those on the fat arms.

                              A 4th version of these arms (perhaps the most rare) is fitted with the two usual but different diameter A-arm bushes, a small one up front and a large one at the rear. This arrangement is in a way, similar to what one finds on the early A4s. Both these designs reflect the thought that, or the recognition of the more significant fore/aft forces directed against the aft bush, which is also evidenced by that bush often failing the most, first. Shameless plug - see also 'Arm-Stops'.

                              A 5th version would be the fat type that has no drain hole (3rd photo).

                              Back to ball joints, the reason for my earlier post is simple. As your 1st photo attests, there are some very similar parts there not everyone might recognize as being different enough to matter (not everyone has done forged arms on the rear), and it would be easy to not have the proper or the intended joints, or perhaps not even two true mirrored twin joints; and not know it. When folks are shopping for their own D-I-Y project or even reviewing what a Garage has done for them, they need to know as much as possible; and sometimes more than the Garage does.

                              A-arms 2 different Screen Shot 2021-02-22 at 09.03.57.png A-arms thick and thin Screen Shot 2021-02-22 at 08.34.46.png A-arm forged fat no drain hole Screen Shot 2021-02-22 at 09.30.20.png
                              Last edited by Lago Blue; 22 February 2021, 19:54.

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                              • #30
                                Originally posted by M2ki View Post

                                Early ones are much thicker.





                                How? With what ball joints? Pics?
                                As I mentioned, in the USA we only had 1 type of Forged Arms. However every B4 cars (Cab, 90) came with forged arms.

                                I used the much thicker CGT front sway bar in the rear so i had to made some custom linkage (original was too short for this combination and interfering with the axle)

                                Ball joint # 893-407-365 E

                                Attached Files
                                sigpic

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