Hi: I have an 03 disco with the 4.6L engine and it is doing the same thing...the belt is jumping inwards 1-2 grooves toward the block on the PS pulley. Here is a pic of the PS pulley, the
adjacent idler pulley and the AC compressor pulley. definitely looks to me like the PS pulley has moved outwards some. Do you have any pics of what you did to correct the placement
of the shaft for the PS pulley? I assume here you took off thePS pulley and pryed on the shaft to move it inwards and then re-installed the pulley on the shaft....is that correct?

 

just checked the PS pulley and it's in the correct orientation (front stamp facing outward)...so my pulley has walked out some.

 

Hi. Answered in direct message too.
Picture in post #1 shows the pulley and triangular flange on the steering pump did self-slide outwards its shaft a little over 1 groove.
Gently hammering them as a single unit inwards, did reposition and realigned the grooves and have not given trouble since. It ended so well that still have the new belt in its unopened package and am running for 2 years ! with the old belt that is 1 groove narrower ! as lost by shaving 1 groove ~3mm when trouble happened.

 

Did you remove the PS pulley before using the hammer on the triangular mounting plate?

 

I believe I did to avoid deforming it while pushing - hammering - forcing it back in.

 

On a lot of rigs, you have to use a tool that threads into the shaft of the pump and there is a nut that is then put on the outside of the pulley to push it onto the
pump shaft. with the design of this pump, ie: with that triangle mounting plate, I wonder if the shaft has a threaded end that you could put the installer tool onto it
to push it back into place?

[edit]...just checked and the end of the shaft does not appear threaded....so it must have been press fit when the pump was built.

 

note: I came across this video where the guy takes the PS pump off and pushes the triangle mounting plate back onto the pump using a big C clamp and re-installs it.