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MG MGF Technical - Twitchy Ride

hi,

just bought an MGF, the second i've owned. its a 1996 VVC.

While driving it back i noticed a few things.

1) when driving in a straight line the car seems to wander. feels a lot more twitchy than the previous 97 vvc i owned. Getds worse at higher speeds.... 100mph is just scary.
2) when accelerating car turns right
3) when i lift off the power it pulls left.

Any thoughts?

thanks

garry
garry

Several options to be checked.

Front or rear ball joint(s) or wheel bearings could be worn ?

Rear rubber bushes could be worn.
I'd recommend to add cheap compliance washers from B&G in any way to the linkage between lower arms and tie bars, later.

Could be just only a wrong ride hide together with the height related toe angles *out* of tolerance .

On the other hand it could be a known problem with the tracking at early MGF. I had such mad throttle steer with my first MGF. (see case B below)
Mine was a VIN 5127 from May 1996 and was cured with help of a technical bulletin (nearly forgotten one in these days.

I'd try myself to analyse the problem and rule out the easy to safe costs.

1. Measure the ride height and get back with results and the ambient temperature at the time you measured.

If confirmed as OK
2. have a test ride on a straight smooth motorway with low traffic:

Go with medium speed, lets say 30 to 40 mph.
A. Test for front axle toe angle problems:
Hard acceleration/deceleration without using the brakes.

Change to low gear and app 3.500 revs and hold the speed.
- Now kick the accelerator, so that the front _lifts_
- Quickly remove your foot so that the front dives down
Repeat some times and hold tight the steering wheel.

Does the car steer itself from one side to the other ?
(note result)

B. Test for rear axle toe angle problems:
Smooth acceleration/decelleration without using the brakes.
Same speed as above, but use a high gear and revs below 2.000
Careful accelerate and decellerate. The front of the car must NOT lift or dive.
Acceleration acts on the rear suspension only in this case.

Does the car steer itself from one side to the other ?
(note result)

If you get a remarkable case B throttle steer problem, then anything with the rear suspension causes your problem.
(Wheel bearing, play in rear lower arm ball joint, or things like that)

If the problem appears more in case B with front up down moving, then you have a problem with the front suspension. (Not an easy, put possible repair)

Hope this makes sense.
HTH
Dieter


Dieter

Garry

Ref the wandering at 100, my 97 vvc did exactly the same thing on any motorway journey to a point where I was afraid for my life when I hit any motorway and would sit terrified in the slow laneat 55mph. All I can describe it as is that it felt like it was blowing a gale outside or I was driving a highsided vechile.

Quick fix for me was a front splitter from Brown and Gammons, once fitted car droce in a straight line on the motorway and was like a different car. One step further was to have the lowering knuckles fitted, this improved things even further, the only dwonside I found was a slighty harder ride and a fear of speedbumps!!!Good luck
Arron
Arron

I test drove an MGF that was like new except for a tendency to steer by the back on accelleration or lift off. It turned out on inspection that the rear subframe was bent affecting the handling and making it scary to drive fast. Needless to say I purchased a different F as the likely mode of damage, given the perfect condition of the rest of the car was a backwards spin over a kerb.
Phil Stafford

Had exactly the same problem on my 99 VVC (although pulling left under acceleration and and right while decelerating). Turned out to be a rather dangerously knackered n/s rear wheel wheel bearing. Knackered to the extent that there was a good inch of play on the wheel! (It was a progressive problem that I had got used to....)
Pete Davey

Having seen 130mph on the clock and competed with the car in various form of motorsport while still on absolutely standard spec, it seems to me there is no inherent stability issue with the cars, so if an F is twitchy there must be something wrong.

In our case, we had the same problem occur and tracked the cause to a wheel bearing as Pete outlines.

A further cause can be a mismatch in tyres between front and rear if not the same type of tyre has been fitted all round. Extreme example: try fitting gravel rally tyres on the back with normal road tyres on the front, gives heaps power on / power off throttle steer! The same effect occurs to varying degrees whenever the construction/tread of the rear tyres allow more squirm than those fitted to the front. For that reason alone it's preferable to stick to the same pattern front & rear.
Paul Walbran

This thread was discussed between 19/01/2006 and 23/01/2006

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