Hello can any one tell me if the power steering box from MKX will fit the 340?

 

I'm guessing yes. Hopefully someone else here can confirm this.
The Mark 10 is supposed to have this variable assist power steering _ which means that the faster/harder you turn the wheel the quicker the power steering reacts.
If you are just motoring down the road, there is less effect on the wheel _ slightly more difficult to steer, you might say.
There is a "quill valve" that controls the amount of oil flow into the chambers of the box.
The quill valve is connected directly to the steering wheel, the harder you turn the wheel, the more oil and pressure is built up in the chambers and thus makes it easier to steer.
If you just turn the wheel in small increments, the valve moves very little, this gives some road feel with out making the steering seem "to easy".

This is what's on my 340.

 

Just be careful what we're talking about here.

The Mark 10 will likely have the same Burmann steering box to the Mark 2, but the drop arm may be a different length. The internal worm gear may be a different ratio too.

Later cars had the Marles Varamatic box which varied the steering ratio using a logarithmically cut worm and roller, with a separate slave piston to provide the "umff" to the steering. This meant the ratio was quite low around steering centre and went up as full lock approached to make the number of turns, lock-to-lock, less.

Both types had a torsion bar on the input to detect steering effort and only apply power when necessary. So at speed on a road, power was minimal, and when parking, it was at maximum.

I think the Marles box is interchangeable, and the Burmann probably is, i.e. it will bolt straight on, but the ratios might differ, but then, does it matter ?

 

The 340 in question has the Adwest (Marles) power steering box fitted as did the 420, as far as I can see the only difference is the hydraulic hose port position, which should not be difficult to overcome? I can get hold of a 420 box, The one currently fitted has far to much free play so I assume it is badly worn.

 

My box was shot.
I took it to a machine shop and they made some new bushings.
Put the whole thing back together with new "O" rings and seals, and I'm good to go.

 

The Marles variomatic will not bolt onto the front beam originally made for the Burman unit. There is a recess added into the beam to allow for the Marles box. I have a 340 front beam for my MK2. I will attach photos.

bob

 

Thanks for the reply, problem now overcome.