Manual steering stiction issue Mk4 Roadster

[Nigel Allen]

Hi Guys,

I have a stiction issue with my manual steering. It has always been problematic, and is most noticeable when turning the steering wheel between center and 90 degrees in either direction. Strangely the more the vehicle is driven in any one session the worse it gets. Once past 90 degrees it is less noticeable as the self-centering tends to mask it. Unfortunately it causes under / over correction and makes driving stressful. At first I thought it was just my arms getting tired, but the stiction definitely does get bad enough that you just end up going home and putting the car away because it sucks.

Some extra info:
- With the car on stands, the steering rotates freely lock to lock and there is no binding.
- Caster is set at 4 degrees and stability is good. Alignment is per recommended. The wheel aligner remarked that the stiction was likely to be tight ball joints and that it would loosen up with time. After 4,000miles the issue is still bad.
- Tyres are Sumitomo HTRZ 245/17, soon to be replaced with Nitto 05
- IRS rear
- Ball joints are as supplied by FFR, upgraded the boots. Greased with standard moly grease.
- Steering shaft assembly is per FFR, with RT turn signal assembly added.
- Steering rack was supplied by the local FFR agent (now long out of business). He made it his deal to remove any information from the supplied manual rack, although word is that it was supplied by Unisteer. It is a traditional manual rack, not a PS rack that has been converted.

So just wondering if anyone else has had this problem, or better still has a solution?

Cheers,

Nigel in South Oz

[CraigS]

I have never heard of this problem. If you drove enough so it got bad could you quickly drive to your garage and jack up the front to test it? Would it feel bad or would it fix itself as soon as it's on the jack? A technique to diagnose it would be to disconnect the outer tie rod end from each side one at a time and see if it feels different.

[totem]

If the steering turns freely, I suspect the lower ball joints my be the cause. They support the whole car weight. Check if fresh greasing makes a difference.

Otherwise, the steering rack pinion tension might be too tight. You can try loosing the huge nut at the end of the steering column by 1/4 turn.

Do manual rack have grease nipples?

[Rdone585]

Can you replicate the stiction issue with the car not moving? Example, perhaps placing garbage bags between your front two tires and the floor (this allows easy turning of the tires), and see if the issue is reproducible with the full weight on the tires. If you are able to reproduce the issue then you can proceed as Craig suggested to narrow down the issue to one or more components.
Some other diagnostic questions:
Another thought (since you mentioned that you are in sessions, i.e. track event), is it possible you are experiencing severe bump steer?
When it "sticks", is the suspension undergoing a lot of deflection?
If you make a smooth turn at slow speed, does the stiction issue present itself?

[rich grsc]

OK, just a thought, upper ball joint plates, straight or angled? If angled, do you have them on the correct side?