Ghost
New Member
Have done a search but not been able to find exactly what I'm looking for, I guess I'm after a how to guide or some specific advice.
I've got a 1991 Defender 90 fitted with what I think is the original 6 bolt steering box, pump, pipes and reservoir. Everything is in good condition with no leaks and has been bled properly. However the steering is still a bit heavy for my liking, don't get me wrong it's an improvement over manual steering but with a small Mountney wheel, Terrafirma steering damper and 235 mud tyres it's just a little bit too weighty. I wouldn't mind but it's a toy I use for off roading and trials and when I need to change from lock to lock quickly at slow speed it requires two hands and a firm grip on the wheel, whereas the other 90s and Discos on the trials scene all have feather light steering that can be whipped round with one hand.
A couple of people have had a try and the general consensus seems to be the 6 bolt box is much heavier duty than the 4 bolt and as such provides a heavier steering feel. But before I change it for a 4 bolt I want to find out if it's possible to modify the 6 without taking it out. I've heard references to removing 'spool valves' to increase the flow of ATF, and likewise boring out the high pressure connectors of the power steering pipe to do the same thing.
I'm aware this will reduce the life of the pump and the box but as it's only an off road toy and I don't do any great speeds or distances in it it's a price worth paying, especially as I have a large pile of spare boxes, pumps and all sorts from rebuilding it! So if anyone's done what I'm suggesting or knows how it's carried out any advice would be appreciated.
I've got a 1991 Defender 90 fitted with what I think is the original 6 bolt steering box, pump, pipes and reservoir. Everything is in good condition with no leaks and has been bled properly. However the steering is still a bit heavy for my liking, don't get me wrong it's an improvement over manual steering but with a small Mountney wheel, Terrafirma steering damper and 235 mud tyres it's just a little bit too weighty. I wouldn't mind but it's a toy I use for off roading and trials and when I need to change from lock to lock quickly at slow speed it requires two hands and a firm grip on the wheel, whereas the other 90s and Discos on the trials scene all have feather light steering that can be whipped round with one hand.
A couple of people have had a try and the general consensus seems to be the 6 bolt box is much heavier duty than the 4 bolt and as such provides a heavier steering feel. But before I change it for a 4 bolt I want to find out if it's possible to modify the 6 without taking it out. I've heard references to removing 'spool valves' to increase the flow of ATF, and likewise boring out the high pressure connectors of the power steering pipe to do the same thing.
I'm aware this will reduce the life of the pump and the box but as it's only an off road toy and I don't do any great speeds or distances in it it's a price worth paying, especially as I have a large pile of spare boxes, pumps and all sorts from rebuilding it! So if anyone's done what I'm suggesting or knows how it's carried out any advice would be appreciated.
