Apparently when the PAS units are installed in 3.8S and 420 cars with their respective Idler arms...The Pitman Arm and Idler are both move horizontally left and right in the direction parallel to the center tube. This appears to be the correct Geometry to reduce wear on Pin Bushings at ends of center rod. they are mounted with 3 bolts each and their axis of rotation is vertical 90 degrees, dur to the rotated holes on the castings.

When we look at the Manual Box and it's associated Idler Assembly, the pitman arm and Idler arm are moving left to right at about 10 degrees off of horizontal because the 4 mount holes are rotated on the crossmember, and the Vertical axis of rotation for both is 90 degrees to the 4 hole pattern in the castings. as the crossmember has rotated mount holes, it appears that the pin bushings will suffer more wear.
see this post for pictures: https://www.jaguarforums.com/forum/m...4-3-8s-296438/

DOES ANYONE KNOW WHY JAGUAR DID THIS? is it to help the car re- center to straight ahead?

Am i wrong in wanting to CUT and re plug weld the captured nut plate so that the mounting pattern for the idler and steering box allows for a vertical axis and less wear on the pin bushings?
ALL EXPERTS please advise, thank you

 

I had a look at the manual system on my car and the Adwest Marles on a spare subframe (both RHD). As you wrote, there's a clear inclination from vertical in the box and idler of the manual. There might be a very small inclination in the PAS, but, if so, it's much smaller. As to why it's there, the box is in a tight space and it might help with clearance from the chassis rail or at least the flange on it and getting the steering column past the engine ancillaries. There are other possibilities like self-centering and stiffening the system, but they seem unlikely.

I wouldn't try to change the arrangement. It seems like a lot of work and it might cause clearance issues for the box or the column. For the small slope and motion, I think the bushes should be able to take up the angle change.

In the event that the bushes on your car are deteriorated, the general opinion is to avoid the pin and bush marketed as 'standard' as they don't last very long; the 'uprated' are much better. If you want to spend less, there are poly bushes available. I think someone on here used them, but I don't know how they performed.

 

 

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... but wasn't your original question about the angle changing as the steering gear moves from side to side?