Ok hears the problem I have. When I brake the steering wheel shudders, I have read the forums and apparently its the steering rack.

But when I hit speeds of 100Km+ the car steering shudders slightly. I have changed suspension, have checked the steering by jacking the front end up, both wheels off ground, locked the steering wheel and there was no movement in the wheels when steering lock. Ive had wheel alignment and balance and it still shakes. Yet no movement when jacked up.

I think my trans is going because when changing from reverse to drive when engine is cold it takes about 5-10 sec for the trans to kick in, but I dont think this can be causeing the shaking at high speeds or braking.

Is it possible for the steering rack to be causing both errors and if not what else can it be. When I bought the car it was shuddering when braking so I dont no how long the steering rack has needed replace if it needs replaceing at all. The car needed a new ball joint so I figured that was what was causeing all the shaking, but it turns out theres more.

Any tips would be benefical.

I have the same problem on my TR ... shuddering when braking, just get your discs machined :)

And again with the transmission, don't worry about it... but it's probably a good idea to let her warm up at least a little bit or you'll get a most annoying "clicking" coming from the engine (tappets sp?)

When taking a long sweeping uphill right bend on the way home from work the car shudders serveraly from about 90-120km but the same bend on the way to work which is a left bend the vibration are nowhere near as bad.

The disc's look smooth and machining them seems to be a waste of time from what ive seen. On the forums someone has had similar problems with brakes vibrating and machining wasnt the solution but steering rack was.

What im basically wondering is if weather or not steering rack could be causing the vibrations at high speed or if there is something else. Im pretty confident that the disc's are fine and that its the steering causeing the shuddering when braking.

Basically when the car is jacked up me and my friends couldnt get any movement from the wheels but for some strange reason when i drive the steering wheel always vibrates and shudders.

seeing as its like $30 to get both front discs's machined, why not do that, and then you can cancel out a possible factor?

-turning right loads the left hand tyre, if the shimmy stops or is reduced then obviously it's the left hand tyre. If it's shimmy-ing when turning left, then its the right hand tyre. If you have checked the wheel balancing on both front, it will be a tyre delamination. Not common on non-retreaded tyres but very common on retreads. Change the the front wheels to the back to see if there is any change.
However you still could be correct about the rack at fault. The easiest way to check this is to get someone in the car moving the steering wheel a bit from left to right. while you check the tie rod ends, and lower ball joints. Do not jack up the car car when doing this, because you want the load on the front suspension.
If it is the rack you will feel and maybe hear a clicking sound.
Finding the fault is a process of elimination, tyres first, ball joints next, then the rack.
I hope this helps.