I changed the engine & gearbox on my manual XJ Sport 4.0. New engine has done 90k miles. Car has done 206k. The steering is lumpy at low speed and doesn't self centre. Over 20mph it is fine. I have changed the relay by the LHS A post for a known good one from one of my other cars. Any thoughts? Could it have an air lock? Thanks
Charles

 

Assuming your power steering fluid isn't low, which would cause the pump to groan somewhat under operation? You most likely don't have an airlock as the system isn't sealed in the conventional sense. Usually, just topping up the fluid and turning the steering lock to lock will expel any air. The fluid level may drop, which just requires further topping up.

Is the power supply connected to the steering pump? If so, check that it's clean and tidy. Do you have power at the connector? Fuses ok?

Mechanically, are the ball joints at the end of the track rods ok? Are the rubber gaitors and seals intact? If the gaitors split, it can allow crud etc. to build up inside, affecting operation. If the ball joints are seized/stiff, likewise.

Are your wheels balanced and tyre pressures ok?

Can't think of a whole lot else, except that the steering pump may be suspect.

 

Hi Atco,

Sogood has covered most of the possibilities, but if the rack is a ZF Servotronic, there is an electrical transducer or solenoid mounted on the pinion housing that changes the valving for more power assist at low speeds. Is it possible the solenoid didn't get reconnected, or there is a problem with the electrical connector? I can't recall the exact speed where the power assist increases, but I think it's below 20mph or 13mph or something like that.

Here's a diagram showing the transducer, which is Part 7:





Cheers,

Don

 

Thanks for the replies. You mention a power supply to the pump. That is one thing I haven't checked. I have a new cable to go from rack to wherever it goes and I will try changing the solenoid on the rack. Oil wasn't low and has never groaned, I know that sound! The engine has done half the mileage of the car but it did have a leak on the rack of the donor car so maybe previous owner ran it low and ruined the pump.... I still have the old engine with the pump tho. Will look at the w/e and will post the solution when I find it.
Kind regards
Charles