home news shop history forum membership galleries regions calendar contact
   

Go Back   106 Rallye Register Forum > TUNING, MODIFICATIONS & UPGRADES > Suspension, Handling & Brakes

Suspension, Handling & Brakes Suspension set ups, uprated brakes

Reply
 
Thread Tools Display Modes
Old 03-04-2016, 10:02 AM   #1
micheldeman
106 RALLYE REGISTER MEMBER
 
micheldeman's Avatar
 
Join Date: Jul 2014
Location: Netherlands
Posts: 278
User Gallery
front suspension legs differences

In my search for new front suspension legs after kwik shit have damaged one of mine when pressing out the hubs, I have found that there can be quite some differences on the front suspension legs. I am trying to gather and summarise and update all information here.

Reason for this topic...

During my search, I notice that different people use different names for different meanings. Here's a list of names that correspond to the numbers on the picture and which are relevant for my findings:
1 = Knuckle or swivel pin, as a whole you can call it strut or suspension leg.
2 = lower suspension arm or wishbone
3 = Hub
5 = wheel bearing



1) Hub:
Hubs can have 3 or 4 holes, not much further to say about this. You need the right wheels of course, but 3 holes are not applicable to rallyes (and gti's) anyway.
Hub flange thickness can be 5mm or 12mm. With the early 5mm type (up to '99), there is only 12mm meat around the holes where the wheel bolts go through, whereas flat types have 12mm meat all around the whole circumference of the flange.

Hubs can be flat seated or tapered seated. This change came at the same time as with the above difference in thickness.

Later tapered wheel hub with 12mm flange thickness

Early flat seated wheel hub with 5mm flange thickness

These hubs are interchangeable, however you need to change the bearing accordingly.

Non tapered hub (early type)
Bearing Inner Diameter = 35mm
Bearing Outer Diameter = 72mm
Bearing Height = 33

Tapered hub (later type, bearings are just flat seated, not tapered too)
Bearing Inner Diameter = 37mm
Bearing Outer Diameter = 72mm
Bearing Height = 33

So the outer measurements of the bearings are the same, but the inner diameter of the tapered hub type bearing is bigger to allow the hub being tapered. As a whole, the hubs with bearings are exchangeable, but you need to change the drive shafts accordingly, with tapered or flat seating. If you don't, you will find problems shortly with your bearings, see comments below from MHR1294.
The early flat hub type bearing might be stronger as there is a bigger difference between in inner and outer diameter. Don't know about the bearing balls sizes though and can't see the reason yet for having them changed from flat to tapered. However, the hub flange thickness is thinner, so might be weaker.

Number of Splines, length and thickness. All the 4 stud hub drive shafts have the same number of splines = 21, diameter and length.

2) Suspension legs/struts
Suspension legs exist with or without drop link mounting points, where with drop link, the mounting point on the strut can be horizontal The early U bracket types, up to '96, S1 rallye or vertical, later flat plate types, after '96, s2 rallye, GTI. U type looks stronger to me, because the drop link sits straight vertically underneath and can handle shocks better, whereas with the vertical type, the drop link makes a 90 degree angle there, which looks like a weaker construction to me. Beware that the U type bracket has a 10mm hole for the drop link and the flat type a 12mm. Anti roll bar also has a 10mm hole in combination with the U type bracket whereas the ARB has a 12mm hole in combination with the flat type bracket. So if you are going changing to later type suspension legs on a S1, make sure you drill your ARB drop link mounting holes up to 12mm, unlike me


Left: early, up to '96 suspension leg from an S1 Rallye with U type drop link bracket (with 10mm hole for drop link) and 5 inch steering arm. (No power steering)
Left on picture flat type hub with 5mm thick flange
Right: later, after '96 suspension leg from a GTI with flat type drop link bracket (with 12mm hole for drop link) and 4.75 inch steering arm. (With power steering), still with flat type hub with 5mm thick flange.
Remark the difference in height where the drop link mounting point sits.

3) Steering arms:
Steering arm length can be 5 inches or 4.75 inches. 5 inches without power steering and 4.74 inches with power steering as the top mount is turned resulting in more caster, and therefor steering arm tie rod end mounting point more positioned to the rear and therefor made shorter? This still needs to be confirmed.

If you would use the 4.75 inches ones on non power steering, it theoretically gets harder to steer. More caster gives better steerability but again harder to steer. Also heard that more caster improves traction of the wheels.
I can't find any further information regarding the length of steering arms on the struts and the reason behind it, but it most probably has to do with the reasons already explained.

4) Knuckles
Knuckles can have ABS or no ABS sensor mounting points on them. I can't see that this means anything for the drive shafts, hubs or bearings.

5) Drive shafts
There are 2 types of drive shafts, with flat (early type up to '99) or tapered (later type after '99) seating into the wheel hub.
Both types of drive shafts can have ABS pickup points or no ABS pickup points. But are interchangeable as far as I know as I have fitted once an off side ABS type drive shaft on my non ABS S1 rallye.
Number of Splines, length and thickness. All the 4 stud hub drive shafts have the same number of splines = 21, diameter and length.

Left the later tapered drive shaft(after '99, right the earlier (up to '99) flat type drive shaft.

The splines look different here, but that's just optical, they are the same.

6) Lower Suspension Arms
Off course we all use the sports suspension arms, but I don't think other lower spec suspension arms make any difference to the suspension leg

I am planning to go for GAZ coilovers on my S1 (without ABS or power steering) and will have the front legs in power steering position to create more caster, I might want to go for front struts with the 4.75 inch steering arms or will the 5 inch types will just be fine?

Mounting point for drop link doesn't make much difference as long as the drop link version corresponds, but I slightly prefer the U bracket type.

Lowering with GAZ gold or similar:
During my search for new suspension legs, I also asked myself the question, which variant would be the best suitable for lowering with GAZ gold coilovers?
GAZ will replace the standard tube in which the damper slides by a tube of themselves with a bigger diameter, allowing bigger diameter dampers. GAZ will lower the suspension arm in which your tie rod ends are fitted to prevent bump steer. Also the ARB mounting brackets will be lowered in order to line up with the ARB. Standard tie rod ends and drop links can then still be used.
As you can see, the early version with the U brackets for the ARB sits already quite low, allowing only 2cm lowering against a maximum 6cm for the later flat plated ARB mount. So, the later variant with the flat ARB brackets is more suitable to be used with GAZ gold coilovers, or GAZ needs to weld the U brackets upside down

Lowering with other coilovers:
Other coilover sets that will fit onto the original struts with the lower pan removed can't have the lower spring seat sit lower than the steering arm. The name coilover means that you coil will fall over your strut. Coilover solutions like GAZ will allow the lower spring seat to sit even lower. In my opinion a better solution and more in line with the idea behind coilovers. Spring lengths and rate will be matched with your requirements, e.g. 4cm lowering and 300LB/inch. Another thing with these coilover sets that fit onto the original struts is that the steering arm is not repositioned, therefor you will introduce bump steer effect. There are solutions like anti bump steering kits where you fit your tie rod end upside down, bringing your steering arms even too low.

Here they are:

and mounted:

Last edited by micheldeman; 14-06-2016 at 06:14 PM.
micheldeman is offline   Reply With Quote
Old 04-04-2016, 11:03 PM   #2
MHR1294
106 RALLYE REGISTER MEMBER
 
Join Date: Dec 2013
Location: Perth
Posts: 113
User Gallery
Looks good to me

The "U" shape ARB mounting point is only up to 1995/96 or S1. as far as I know all S2 models had the vertical mount type. I've got some struts off a 1996 gti and it's got the vertical style flat mount thingy.

The hub thickness did change at the same time as the hub style. All "thick" ones I've come across are tapered and all the thin ones have been "flat". There's probably some aftermarket ones floating around which are different.

The driveshaft splines are all the same diameter and number - this is how people end up combining the incorrect hub/shaft followed by confusion when the wheel bearing fails after a few hundred miles haha!

The exception is all models with 3 stud style hubs. these shafts are unique and are all tapered - but different angle of taper, diameter and spline number?


p.s can't believe you went to kwik fit for a wheel bearing change.
MHR1294 is offline   Reply With Quote
Old 05-04-2016, 06:43 AM   #3
Cris B
106 RALLYE REGISTER MEMBER

 
Cris B's Avatar
 
Join Date: Aug 2008
Location: t'Internet
Posts: 3,975
User Gallery Car Blog
Can a Mod please sticky this thread, as it's the first time some one has actually explained the hub differences with illustrative photos?
__________________
Cris B is offline   Reply With Quote
Old 05-04-2016, 09:10 AM   #4
Harv
Slower Than Mike
 
Harv's Avatar
 
Join Date: Mar 2007
Location: Louth, Lincs
Posts: 3,356
User Gallery Car Blog
I think the specs should be:
S1 - non-tapered hubs and shafts, ARB with straight links
S2 Rallye - non-tapered hubs and shafts, ARB with right-angled top link
S2 99-on (probably coincides with 3-plug ECU) - tapered hubs and shafts, ARB with right-angled links, ABS brackets on the strut.

Good post though, and I agree that you deserve everything you get from Kwik Fit!

Last edited by Harv; 05-04-2016 at 09:10 AM. Reason: Automerged Doublepost
Harv is offline   Reply With Quote
Old 05-04-2016, 10:37 AM   #5
micheldeman
106 RALLYE REGISTER MEMBER
 
micheldeman's Avatar
 
Join Date: Jul 2014
Location: Netherlands
Posts: 278
User Gallery
Thanks for the comments and input, I have updated the information into the relevant topics.
I think Harv succeeded to make up the shortest summarisation
Just 1 remark to Harv.
S1's and S2's have abs as an option, so knuckles can have abs brackets at early types too, or are you saying that later knuckles all had abs brackets, even when the car wasn't equipped with it?

Quote:
Originally Posted by MHR1294 View Post
Looks good to me

The hub thickness did change at the same time as the hub style. All "thick" ones I've come across are tapered and all the thin ones have been "flat". There's probably some aftermarket ones floating around which are different.

p.s can't believe you went to kwik fit for a wheel bearing change.
A thick flat one would be the strongest?

Kwik fit were able to balance my 3 stud wheels from my 304, no other garage had these adaptors and weren't expensive. First garage to press out the bearings asked 50,- for the pair, kwik-fit 25,- only, but I think the guy didn't know exactly what he was doing and probably pressed on the bearing to push the hub out .
micheldeman is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 10:14 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.