356A ZF Steering Box Issues
 

I am having some serious issues trying to sort a friends 356A Cabriolet in the steering department, hoping someone can help. The issues concern the steering box. The car has been converted from left, to right hand drive. The correct RHD pitman arm has been fitted and the ZF steering box has about 2.4 turns lock to lock, which I believe to be correct.

The problem I am having is that I cannot manage to get sufficient left hand lock. Right hand lock is fine. What happens is the tie rod ends contact the circular hole in the chassis where the tie rod and brake lines go through on the RHS. This restricts the box to 2.0 turns lock to lock. 1.2 turns right, 0.80 turns left.

See picture below:

http://i115.photobucket.com/albums/n...ps127b13b8.jpg


Allow me to explain further.

I have fitted a N.O.S. ZF box at the owners request. The box is identical to that removed (Less the notchiness of the original)!

Firstly I orientated the pitman arm as per page S41 of the workshop manual, that is, with the index marks aligned on the pitman arm and the shaft. Next I checked the orientation of the input shaft, in that the scribe on the shaft aligns with the index mark on the body of the box, it does. See picture below:

http://i115.photobucket.com/albums/n...ps7a9ac6bc.jpg


At this stage, I also checked the box lash and confirmed that this position was the "High spot" of the box, and in fact it was. I then confirmed that in this position, the pitman arm was in the same position as the pitman arm on the old box (It was).

After fitting the box in position, it is impossible to align the wheels so that the centre position of the box is in fact straight ahead for the right wheel. It appears the tie rod on the right hand side is too long! There is not enough thread to shorten the rod. See thread position in the first pic)

And this pic shows the position of the right side wheel with the steering box in the central position, with the tie rod at its shortest length as per the first picture!

http://i115.photobucket.com/albums/n...psed3fb9d0.jpg

I see this problem could be eliminated by simply moving the pitman arm a spline or two on the output shaft towards the left hand wheel. But the index marks then would not line up on the pitman arm, not to mention some Ackerman displacement! However, something must be amiss, what have I missed? I am driving myself nuts with this issue! The parts book lists different tie rod ends for left and right hand drive cars, however I have been unable to source a photograph of these to check if there are any differences. Is it possible that the RHD tie rod end for the right side of the car is offset to clear the chassis hole? Any ideas? :confused: Thanks and regards, Carl

Carl, without further investigation and no experience with the conversion. The first thought that comes to mind is that the pitman arm setting would be a mirror image of the lhd location not the same unless it is centered. Another thought, are right and left hand drive pitman arms the same?
Good luck, you might also pose the question on the 356 registry website. Lots of very knowledgable lads and lasses there.

Thanks for the reply Rusty. Next step is to have another look at the Pitman arm as you suggest. BTW, nice selection of cars in your garage.

Regards,

Carl.

Just a quick follow up. I worked out the problem. Two issues;

1. The pitman arm ended up being a modified LHD unit, meaning the offset of the ball joint recesses was not carried over symmetrically for RHD, displacing it to the left. The person who modified the arm did a pretty good job of moving the mount for the steering damper which made identifying it as a LHD unit difficult; until I looked at a LHD unit :)

2. The index mark on the pitman arm had been scribed one tooth clockwise from where it should have been.

Anyway, it's all back together and I have to say, the car drove nice, here is a pic of me with the finished project.

Regards,

Carl.

http://http://i115.photobucket.com/a...ps1ab53ded.jpg