MGF Compliance Washers
Improvement of the suspension & the rear tie-bar
(alternative to PU-Bushes at the rear tie bar)

Montage der Abstandscheiben/
Assembling of the Compliance Washers


Die vor-/rückwärts Bewegungen der hinteren Halbachsen des MGF sind durch Reaktionstreben begrenzt. Beim Beschleunigen/Verzögern durch Gasgeben bzw durch die Motorbremse muß die Last auf die Ober/- Unterlenker abgefangen werden.



Diese Zugstange ist (links im Bild) beidseitig in Gummi-Metalllagern dreh- und schwenkbar gelagert. Das dicke Lager (rechts im Bild) nimmt im Wesentlichen die Vor und Rückbewegungen des Hilfsrahmens gegenüber den Rädern auf.
Beim MGF ist das äußerst schwabbelig und weich gestaltet. Beim Beschleunigen oder Verzögern durch Gaswegnehmne ändert sich dabei die Spur um mehrere Grad !!

Man kann diesen Effekt selbst ansehen:

- Handbremse anziehen und Kofferraum öffnen.
- Mit festem Griff das Auto hinten an der Abschlusswand greifen
- Das Auto nun hin- und herschieben und dabei das rechte oder linke Hinterrad von oben betrachten.

Es wird einem fast übel dabei, ...
Ob das so sein muss ?? Was hat sich der Konstrukteur dabei gedacht ??

Wir (ich) wissen es nicht. Jedenfalls ist das bei den Racing Ausführungen des MGF anders gelöst. Hier übernehmen feste Nadellager die Funktion des grossen Gummilagers. Mir gefällt es nicht und darum probiere ich halt auch mal aus, wie das funktioniert. Kann sein, dass es nicht gut für die anderen Lagerungen ist. Egal, ich weis dann aber, wer es (selbst) zu verantworten hat. :))

Zur Modifikation dieses Schlabberlagres gibt es bisher zwei Möglichkeiten:

A. PU Buchsen von Powerflex, z.B. erhältlich in DE bei Ffritz Schmidt.
B. Montage sogenannter Compliance Washer von B&G oder selbst hergestellt aus Niderdruck Polyethylen.

Diese Scheiben nehmen das Spiel zwischen den Metallscheiben und dem Gummilager heraus und machen die Lagerung straff.

Erforderliches Werkzeug:
- 18er Ringschlüssel
- diverse 13er Ring- Maulschlüssel
- Hydraulik Wagenheber
- Böcke

Material :
- 4 Stück Compliance washer (Da= 65mm, Di= 26mm, T= 3mm, PVC)
Meine Scheiben hat mir Olaf günstig verkauft. Er hat seinerzeit doch gleich PU-Buchsen montiert. Hier seine PU-Buchsen Seite

- Lithium Fett

ACHTUNG:
Nach Einbau dieser Scheiben muß die Spur neu eingestellt werden.

The traktion of the engine to the cars wheels let them move the wheels forward and backward related to the cars body. In our MGF case is the subframe involved. The lower and upper wishbones can't hold this force alone. They get supported by a tie bar which is attached at the MGF to the lower wishbone.

This tie-bar is fixed on both sides of the wishbone with rubber-metal dampers which carry movements in all directions. The main movement is to the front and rear. The damping function is very weak at the MGF. The tracking angels change by one or more degrees under hard acceleration/decelleration.

This effect can be experienced easy:

- Pull the handbrake and open the rear boot
- Shift the whole car forward and backward with a strong grip to the rear boot wall
- See from above to the rear wheel movements while shifting the car

You will nearly get sea sick on looking at this tracking changes, do you ?
Must this be ?
Is that designed for just this behaviour ?
We don't know it exactly. It got changed at the MGF cars, so several chaps tried to get rid of this gaps and strange tracking behaviour by modifying the rear tie bar damper.

The currently availiable options are:
A Polybushes from Powerflex or Superflex or other companies. Sold direct from the OEM or by B&G and other suppliers.
B. Compliance washers to fill the gaps, supplied i.e by B&G

These washers make the dampers tough. The gap between metal washer and rubber gets filled. No play any longer.

Required tools
- 18 mm wrench
- several 13mm wrenches
- hydraulic jack
- axle stands

Materials:
- set (4 pcs) of Compliance washers
(Od 65mm, Id 26mm, T 3mm, made of PVC )
I got this washers from Olaf who installed the PU-bushes instead. See his PU-bushes site
- Lithium grease.

ATTENTION:
The cars tracking must be adjusted for new after this works.

Die 18er Mutter am Gummilager lösen. Dabei die Stange mit einer Schweren Pumpenzange gegen Mitdrehen sichern.
Das 'eingebaute' Spiel zwischen Gummiblöcken und den gelb verzinkten Anschlag- bzw Druckscheiben ist hier aufgezeigt.
Loosen the large nut wit a 18mm wrench. Hold against with a large gripper to prevent torque bends at the subframe.
Look at the built in play between the yellow steel waher and the rubber-metal damper at the standard setup
Die 13er Schraube zur Befestigung der Zugstange hinten herausdrehen. Sehr mühsam, da man schlecht drankommt. Ggf 1/4 Zoll Knarre mit Gelenk verwenden . Loosen the rear fixture bolt at the tie bar. 13mm and pull it off. This is difficult, cause it's hard to reach. (use a universal socket at a 1/4 inch wrench if possible)
Eine unbequeme Arbeitshaltung. No easy works location
Die Lagerseite der Zugstange, demontiert. Im montierten Zustand ist die Mutter mit 80Nm angezogen und presst die innen liegenden Metallhülsen fest zusammen. See the standard bearing set of the tie bar to the lower arm.
The inner metal pipes of the rubber-metal damper is pressed to each other if assembled with a torque of 80Nm to the nut.
Zur Demonstration habe ich hier ein Foto des Lagersatzes mit den Abstandsscheiben gemacht. This picture shows the location of the added compliance washers (black)

Zum Wiedereinbau der Zugstange:


- die innen liegende Hälfte des Gummilagers vormontieren (nicht im Bild) .
(Stahlscheibe, Plastikscheibe, Gummilagerhälfte)
Dann erst die Zugstange mit dem Gummilager in den Unterlenker schieben und die Zugstange vorn mit der 13er Schraube wieder anschrauben.
Nun wie gezeigt die äussere Seite des Lagers aufstecken und dann die Plastikscheibe draufsetzen.
Alles schön mit Lithium Fett einfetten.

Up to re-assemble the parts

- shift the tie bar with the inside located half of the pre-assembled bearing set to the lower wishbone
(Steel washer, Plastic washer, rubber-metal)
Then put the inner end of the tie bar back to the position at the subframe and bolt on with the 13mm screw.
Now as drawn fit the outer half of the rubber damper to the wishbone, then the second plastic washer and at last the steel washer and the nut.

Put loads of lithium grease to all parts

Die 18er Mutter wieder mit 80Nm anziehen. Tighten the 18mm nut with 80Nm torque.
Das Ergebnis. The works result.

Diese alternativen grünen Spielausgleichscheiben sind aus speziellem zähem Kunststoff gedreht. (Bilder von Markus)
Fragen dazu an Markus MGFVVC1996_aol.com


Saubere Arbeit und Klasse Material:
(ultrahochmolekulares Niederdruckpolyethylen ) :o)
Murdtfeld S

Wer da nicht drankommt, der kann es auch mit Glockendichtungen aus Gummi für Toiletten Spülkasten Typ *GEBERIT* aus dem Klempnerzubehörladen. Das ist dann aber eben nur Gummi.

The green coloured washers on the left got machinen from best
(ultra-macromolecular, low-pressure polyethylene)
Murdtfeld Typ S
  Zum Schluß die Spur einstellen lassen.
Da die Hinterachse sich nicht mehr durch Traktion bewegen lässt, sollte man dieses durch mehr Vorspur kompensieren. Also hinten nicht Spur Null sondern z.B. +0°10' Vorspur

At last the tracking must be adjusted. The rear axles do not move any longer related to engine traction. In this case you should compensate this with more toe IN.

Never do Toe Zero, but +0°10' Toe IN (+5 minutes each wheel)

From: C Golvala Greater London United Kingdom cgolvala@........com on 28 April 2003 at 11:42:35 (UK time)
Following on from the mostly successful fitting of the Polyflex damper bushes, I tackled the rear tie-bar bush. As guidance I had a couple of old threads, including Roger Parker's instructions for fitting compliance washers, and Dieter's pictorial guide. It was not as easy as all that for this amateur, so here are some notes for those interested:

1) You need a deep 18mm socket for the rear nut and plenty of elbow grease. These are hard to come by, but Teng Tools do one that is stocked by the larger Halfords.

2) The recommendation from Dieter to hold the tie-bar whilst undoing this nut cannot be emphasised enough. When I had to resort to a garage, their air-tool could not shift the nut because the flex in the bushes absorbed all the torque.

3) Dieter talks about using a "Cardan" spanner for the 13mm bolt that holds the tie-bar to the subframe. I bought a "deep-offset" ring spanner from Halfords for the job, because there is not enough room to get a socket and ratchet head onto the bolt. The garage used a socket with a long allen key as the handle - good idea, though the deep offset spanner will do the job.

4) The 13mm bolt is harder to reach on the right-hand side of the car because of two fuel hoses that have to be gently pushed out of the way. On both sides, the lip of metal running underneath the bolt and the lack of space between the bolt and neighbouring bodywork, made it impossible to get a torque-wrench to the bolt. Unless anyone else has a bright idea and posts it here, forget about torquing this to 45Nm.

5) I started on the left-hand side of the car because of those fuel lines and was able to remove the 18mm nut and 13mm bolt without too much difficulty. The head of the tie-bar needs to be wiggled out by pulling down on the bar (which needs movement in the bush), turning it 90 degrees and then pulling forward to get the bar out of the lower suspension arm.

6) This is where I came unstuck. Although I cleaned out rust from the socket in the lower suspension arm, I could not push either half of the Polyflex bush all the way in by hand. I tried to use a G-clamp but the sloping washers made this impossible. The result was that I could not get the front of the tie-bar into its subframe mount or the rear nut onto the tie-bar so as to squeeze the bushes into the arm.

7) The garage suggested (though in the end did not use) threading a bolt through the bush and tightening a nut on the end to force it into place. But you would then have to fit the tie-bar through the bush without dislodging the bush, which would be difficult (see removal method above).

8) I suspect that even if I had got the front half of the bush in all the way, the thickness of the bit of bush that does not go into the socket would have meant that the head of the tie-bar would not line up with its the subframe mount, until the bush had been compressed. If you can get this far, then I think you would have to put the rear 18mm nut on first, tighten it until the head of the tie-bar lines up with the mount and then put in the 13mm bolt. This is a variation on the compliance washer instructions and is what the garage did for me.

9) Finally, after putting the old bushing back together and lowering the car, I found that there is not enough room underneath to move the torque wrench arm sufficiently to click, at 80Nm or even a lower setting. Again, as with the rear damper nut, I cannot see how you do this without a pit.

The good news is that the mod certainly works a treat, with the cornering security much improved. The bushes compress into a shape that I can only call beautiful (you'll see!) and hold the rear wheel toe-setting much better. The garage recommended that I come back in 200 miles for tracking since the bushes will take a few miles to settle in.

Picture courtesy John Thomas (1999)

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