So Mk3 Golf plus axles - more castor FTW...

I can't remember if this has been illustrated so vividly....

Mk2 Golf wishbone on top of a Mk3 Golf plus axle wishbone (GTI/VR6):




And Mk3 GTI/VR6 wishbone placed up against an on-car Passat B3/B4 wishbone:





Front of car to left...




One thing which did look entirely swappable was fitting standard non-GTI/VR balljoints into the Mk3 wishbone... Anyone?

 

Indeed, the wishbones are dramatically different - I've collected wishbones from Passat B3 2.0 and VR6 to VW Mk II, III, and IV with intentions of posting a series of photos and dimensions, but as yet cannot find a Mk I to complete the set

A GTI/VR6 ball joint has its two outermost 8mmd boltholes at 58mm centers vs 55mm for Mk I and II

Just slot the GTI/VR6 wishbone's two outermost boltholes 1 1/2mm towards one another, and a Mk I (edit, Mk I may not), II, or III ball joint will fit perfectly

The GTI/VR6 wishbone's single innermost 8mmd bolt hole is fine as is

You'll also note the single innermost 8mmd bolt hole in MK I and II ball joints is just that - - a hole as in surrounded by material, whereas the GTI/VR6 ball joint 8mmd bolt hole incorporates an open slot toward the car's central axis

 

I`ve got GTI wishbones on my TDI, and the outermost b/j mounting holes were 3mm further apart than the original TDI items (as above).

I only slotted one hole per wishbone (rearmost), and used slightly larger washers to compensate. No issues with several thousand miles done since.

 

Tigger, where are you based? I've Mk1 wishbones. Or give me the measurements you need. The Mk1 holes are 7mm OEM btw.

Cheers for confirming that Stu, I thought they looked near-as. A bit of weld on the back edge would be the perfect finish.

Are you on TDI shafts still? Have you ever had the box off or had reason to check the float on the inner driveshaft cups. Just curious what the fit is like (centred, compressed inwards, stretched outwards), obviously all subject to ride height also.

Passat shafts are marginally longer than Mk3 (6mm - here), so that must be due to the original plus axle ball joints being canted inwards and taking out a few mm.

 

I would not compare balljoint mounting holes as a datum. All three types have different spacings.
The curve at the end of the wishbone that the balljoint sits against would be a better point of reference IMO and from experience.

The discrepancy in lengths between the passat and mk3 gti shafts could be down to the added castor of the gti hub setups, making the sweep of the outer cv effectively alter shaft length at varying steering inputs. ie shaft plunge.

It is awkward to measure shaft plunge on the 5 stud setups due to the outer cv joints being very tight in the drive flange.

 

I'd agree with that. To avoid that, I tried yesterday to measure the wishbone front bolt centreline to the centreline underside of the ball joint.

These were the results:

Mk2	Ibiza Mk2 & 3	Passat B3 & 4	Mk3 GTI/VR6
377mm	377mm	400mm	400mm

... but the canted in nature of the Mk3 plus axle ball joint, and unknown differences between inner hub => CV face position between plus and non means it's tricky to work out relative track increase precisely. Not hard to assemble and check though.

 

Cheers for that, that'd slipped my mind.

 

I hadn`t factored castor at first, because I was swapping in a GTI subframe due to a busted captive on the original.

I hadn`t intended to use the wishbones too, but since the original bushes were shot it was the `easiest` option (considering I thought they were the same...).

I`d bought new GTI balljoints in preparation, but too late realised the were different (canted, as opposed to the `normal` Mk1/2 type the TDI had as standard), so had to retain the TDI ones (since swapped for new) with the resultant wishbone butchery to get them to fit.

As you know I run it ridiculously low (shafts pointing upwards, inner CVs very much squashed inwards) and with around 3.5deg -ve camber, so turn in is awesome (even the GF commented that it turns like it`s swivelling about the centre of the rear axle...making her feel quesy in fast, tight bends... ).

The caveat to that, besides destroying tyres in short order, is a margin of bump-steer (liveable), and the fact the shaft-plunge is bound to be on the excessive side.

I have retained the TDI shafts, but it`s only this week that the o/s inner CV has started to make it`s feelings known. I expected it much sooner, but that`s a little over a year, so not complaining.

I`ll do Curborough on this set-up, then ditch the crap ebay coilovers in favour of a -60mm Spax setup a mate has going spare, and return to TDI wishbones. It won`t be half as much fun, but at least it won`t kill the car as quickly as I am now!

 

Go waay West young man, clear across both the Atlantic and Canada before dipping your piggies-went-to-market into the Pacific at Vancouver, B.C.

So far as selecting datum from which to derive wishbone lengths is concerned, I suggest the following

Flip the wishbone upside down on the workbench (or alternatively elevate the car on stands and eyeball it from underneath), then slacken off the three ball joint mounting bolts and force the ball joint assy as far "out" as the bolts/holes will permit (I've measured as much as 4.5 mm movement between max "in" and max "out")

Note that an imaginary line extending from the wishbone front mount securing bolt axis will pass directly through and at right angles to the axis of the rear bushing securing bolt

Place the edge of a 1 meter carpenter's steel square along that imaginary line, then move the square towards the vehicle's rear until the short leg of the square passes directly over the center of the ball joint assy

Take one's favourite tape, and measure

You'll find that measuring from, say, any part of the wishbone proper adjacent to the front bushing mounting bolt will result in an inaccurate reading, as correctly deriving the radius of the arc described by a pivoting wishbone relies on measuring the length of that arc at right angles to the imaginary line extending between the two mounting bolt axii

I believe this method is more accurate than measuring to bolt hole centres alone or edges of the wishbone stamping, as both appear to vary with year, model, and component manufacturer - - and after all, it's the ball joint centre which dictates the suspension assembly's geometry

Whilst the "canted" ball joint fitted to Mk III GTI and VR6 engined cars complicates this technique somewhat, I have obtained reliable comparative measurements by following the above process then taking an engineers 30mm adjustable square, holding the body of the square against the correctly positioned carpenter's square, sliding the 30mm blade of the engineer's square through the body until the end touches the very centre of the back of the balljoint, marking the carpenter's square accordingly, then measuring from that mark to the edge of the carpenter square's long leg, which has remained on the imaginary line running through front and rear bushing mounting bolts

Sorry I've no piccies to offer, and no I'm not deliberately challenging your 3D imagery skills

Just for interests sake, I also used the single innermost ball joint mounting bolt to fit a conventional Mk II ball joint to the Mk IV and B3 Passat VR6 wishbones (as previously noted, the two outermost wishbone holes would require slotting in order to fit bolts there too), dimensions following:

	Conventional bj (17 or 19mmd)	Mk IV/VR6 bj
Mk II	372mm
Mk III 4-stud	393mm
Mk IV	400mm	406mm
B3 Passat VR6	408mm	414mm

Note I: As previously mentioned by others, with the VR6 bj tapered securing fixture being "canted" compared to the vertical alignment of a conventional bj's 17mm and 19mmd parallel securing fixtures, the above GTI/VR6 wishbone dimensions do not describe the steering hub's lower pivot datum relative to the inner mounting bolts' imaginary axis, but are useful solely for identifying the different MkIV/VR6 wishbones

Note II: A colleague supplied a pair of what he claimed were 17mmd Mk I bj's, which fitted the Mk II and Mk III 2.0 wishbones utilised in this study

However, I think Danster? mentioned there were dimensional differences between the mounting boltholes for Mk I, II , and III bj's, in which case the reference to Mk I bj's in my "today" post of 00.39hrs is inaccurate

 

LcT.

As you cannot supply photos. I suggest that you provide me with a return first class ticket to Vancouver, via Ottowa, so I can meet up with miss daved, and I will sketch your verbose description.

Not that I have any real interest in Mk3 stuff, no I do not want to wide track Mr Eyre, just fancy a meet with you! Well, really fancy a trip to B.C. actually.

ps. Can you supply suitable canvas canoe for tripping? I'll bring my own Beaver Tail.

 

Wooh, that was a read, but thank you!

So can I doubly confirm:

1) where these measurements are taken from. Balljoint centreline to front wishbone bolt centreline?
2) these measurements are with a Mk2/A2 Golf balljoint fitted on the centre hole as a minimum?
3) What the double measurements are for the latter 2

 

Mk2 and Mk3 b/js have identical mounting hole dimensions (excluding GTI/VR6 as discussed).

The Mk1 b/j outer holes share the same dimension, however the inner hole is closer to the b/j itself than the MK2/3 variety.

I have, however, previously fitted a Mk1 b/j to a Mk2 wishbone, purely as an emergency `get home` fix when my Mk2 sheared one of it`s b/js.

For measurement/study you could therefore easily utilise a Mk1 b/j with a Mk2/3 wishbone.

 

Correct, the imagined line created when extending the wishbone front mounting bolt axis to that of the wishbone rear mounting bolt axis, the two crossing at right angles - - to the centre of the back (bottom when correctly oriented in the vehicle) Mk II ball joint, in all 4 cases quoted

See response under (1)

The two orphan measurements of 401 and 414mm were meant to appear on the same lines as "Mk IV" and Passat B3 VR6" respectively, but in the column headed "Mk IV/VR6 bj"

They were derived after substituting the correct "canted" bj assembly for the conventional late MkII 19mmd bj's and manipulating the engineer's 30mm square until it simultaneously snuggled up against the carpenter's 1 meter steel square, and the corner of it's 30mm blade contacted the bottom center of the "canted" bj

A trial fit with the above squares would quickly establish the proposed technique

ClubGTI software insisted on crowding the "orphan" figures up against those appearing in the "Conventional bj (17 or 19mmd)" column

Note: it's important to create a 90 degree angle when measuring from the "imagined line" to the bottom centre of the bj, else lengths for the same wishbone will vary by however many degrees our geometry major wavers from that 90 degrees

In closing, as hobby time permits, for obvious reasons I intend either posting photographs (heh heh, including squiggles on graph paper) or will request an intermediary do so

Apologies my technical descriptions are not as clear as I'm capable, am out of practise

 

Ah, ok.

I've edited the posts to include a table now - let me know if it appears as it should

My data in this post does not use 90 degree angles, just a straight rule from wishbone centreline to ball joint centreline.

So putting the information together:

	Conventional bj (17 or 19mmd)*	Mk IV/VR6 bj*	OEM bj**
Mk II	372mm		377mm
Mk III 4-stud	393mm		400mm
Mk IV	400mm	406mm
B3 Passat VR6	408mm	414mm
B4 Passat 4-stud			400mm

* Measurement from wishbone pivot axis to balljoint centre line @ 90 degrees (LeftcoastTigger)
** Straight rule measurement from wishbone axis (front) to balljoint centreline (Chris Eyre)

Just to check, is your Mk3 data from a 4-stud car or 5?

 

Chris, unless I'm missing something here, accurately measuring the distance between the wishbone pivot axis and ball joint centre is impossible without observing the 90 degree rule

If the datum point - which on these wishbones can only exist in free space - created by the 90 degree rule is not chosen in preference to a physical point on on the stamping surrounding the front bushing, surely one must then identify that specific spot on the surface of the wishbone, presumably on it's pivot axis, from which to measure to the bj - - and accept that the dimension so derived may not permit accurate comparisons with other, differently dimensioned, wishbones whose stampings and general shape may differ even if their critical axii and datum points do not

Aaarrgh! photo and/or drawing pending! patience please

My data in this post does not use 90 degree angles, just a straight rule from wishbone centreline to ball joint centreline.

So putting the information together:

	Conventional bj (17 or 19mmd)*	Mk IV/VR6 bj*	OEM bj**
Mk II	372mm		377mm
Mk III 4-stud	393mm		400mm
Mk IV	400mm	406mm
B3 Passat VR6	408mm	414mm
B4 Passat 4-stud			400mm

* Measurement from wishbone pivot axis to balljoint centre line @ 90 degrees (LeftcoastTigger)
** Straight rule measurement from wishbone axis (front) to balljoint centreline (Chris Eyre)

Chris, the above table is correct so far as my contribution is concerned, meaning I cannot vouch for the Passat B4 figures

Chris, the Mk III dimensions were from a 4-stud plain jane example

 

Tigger, yes to be absolutely clear, the data is not comparable, but it was easy data to get hold of, and gives us ballpark numbers until better data is obtained. So I've put the asterisks on to make that clear. My data will be longer that the 90 degree data, since it's the hypotenuse, but if nothing else it validates via those ones that match and by inference, we could estimate a B4 Passat 90 degree measurement at 393mm

I've edited in 4-stud so we know where we are with the Mk3 data.

 

So to continue with this data, surely the next step is to calcuate the increased track width as a result of wide tracking a Mk2 Golf?

I've sliced out my data as it's estimational.

Only thought is the VR6 canted ball joint might skew things - Tigger, interested in your thoughts:

	Conventional bj (17 or 19mm)*	Mk IV/VR6 bj*	Wide tracking gain per side (Mk2 bj)	Wide tracking gain per side (VR6 bj)
Mk II	372mm	n/a	n/a
Mk III 4-stud	393mm		+21mm	n/a - VR joints not used
Mk IV	400mm	406mm	n/a to Mk2	n/a to Mk2
B3 Passat VR6	408mm	414mm	n/a - Mk2 joints not used	+42mm
B4 Passat 4-stud

* Measurement from wishbone pivot axis to balljoint centre line @ 90 degrees (LeftcoastTigger)

I've added the 2 figures in green to the Wide tracking FAQ here. Two more needed and once we understand the effect of the canted VR balljoint, the spec of all wide tracking options are there

 

Agree, it does seem a lot.

I'm purely taking the difference between the measurements in the above table, which is 414mm less 372mm.

Time to look at some driveshaft lengths for corroboration I think.