Seat Rebuild

The driver’s seat always gets more wear and tear than any of the others, since that’s the seat that will always be in use, and this was no exception.

The seat’s foam cushions were compressed, leading to a lack of lumbar support on the back and slack fabric covering on the bottom.  I had planned to rectify those issues for quite some time, but replacement foam cushions are not available for the Classic, be it through Genuine Parts, Rimmer Bros, Dunsfold, Nationwide Trim or Exmoor Trim or any of the other likely sources.  With no new parts available, you have to either find good second hand parts or mend your own.  As a result, this is a job that has been on hold for quite some time.

Unfortunately, the seat developed some other issues in the last week – the recline mechanism jammed and the frame started creaking from near the right shoulder (these sounds are often triggered elsewhere but emanate from somewhere unrelated).  The seat back also seemed to be twisting my torso slightly towards the centre of the vehicle, though that could just have been imaginary.

Given their speciality in Range Rover Classic trim, a call to Nationwide Trim was required for advice.  They advised me that the recline mechanism is possible to be worked on, but that it has lots of parts with loose ball bearings.  They said any fault would probably be self-evident once stripped down and that the seat would have to be removed from the vehicle for disassembly.  They also said that is would be possible to repair my cushion foams by bonding the splits that tend to occur in the recesses that accommodate the frame and by adding layers of foam sheet under the existing pads to pack them out to the correct profiles.

Removing the seat is simple enough, but you do need the correct allen key for the front bolts and star drive for the rear bolts and lower seat belt anchor (the belt is connected to the seat, so must be disconnected).  If the recline mechanism is working, wind it all the way forward to make removal through the door way easier.

With the seat laid on the floor, start by removing the bottom covering.  Prise out the recline knob’s inner disc and then undo the 10mm nut to remove the rest of the knob.  Pull the plastic side trim panel off the other side of the seat base by pulling it directly down and away from the cushion.  Then undo the two 10mm bolts that secure the front of the seat base to the seat tipping arms – this will allow the seat runners to tip away from the rest of the seat, giving access to the fabric retaining clips.  Work around the steel tabs along the insides of the front and side edges of the seat base, prising them open with a screw driver to allow the fabric to be pulled down and over the frame to expose the foam pad.  At the rear edge,  simply pull the edge of the fabric up towards the bottom of the cushion to unhook the plastic channel from the top lip of the frame.  You should now be able to remove the base pad and covering, and separate the cover by feeding the plastic strips through the pad from underneath.

The seat back covering is a bit trickier.  The bottom of the cover is opened by rolling the hidden joint open – each edge has a plastic strip, and the plain edge is just rolled over and tucked into the edge with the U-channel.  This will expose three plastic pegs holding the rear side of the fabric into the lower frame edge – pull them out by gently pulling the fabric away from the frame.  The side plastic covers need to be removed by undoing the small self tapping screws (one each near the bottom of the  curved surface) and pulling the plastic dowel out of the seat frame and then sliding the covers off.  Then you will see the front sides’ edge piping running back to two steel tabs on each side above the plastic covers’ positions – prise these open to release the piping.  The fabric is held in position along the vertical stitches in the front and back panels by bungies in the front and steel wires in the back – the bungies run down cotton sleeves inside the front and hook into the frame near the plastic pegs removed earlier.  The rear steel wires hook in similarly, but are a little fiddle because they tend to be tangled in the squab’s coil springs.  Be careful when undoing these as you don’t want to tear the relatively delicate cotton sleeves.   With those disconnected, you can roll the fabric cover about half way up the seat back.  There are more fasteners, but they will become apparent as you move the cover up.  You don’t need to remove the arm to do this job – the cover has a slip to allow it around the arm.

As always, reassembly is the reverse of disassembly.  Just be methodical as you take it all apart and putting it back together will pose few problems.

The seat recline mechanism is fairly simple.  The side knob rotates a hexagonal sectioned lateral shaft.  This shaft passes through two small steel boxes mounted atop the steel frame.  Each box has a pair of crown wheels to translate the rotation of this lateral shaft into rotation of longitudinal shafts that run inside the sides of the base frame to the rear, where they have a worm gear engaging on geared quadrants on the seat back frame.  The seat frame is prone to cracking on the sides beneath these gear boxes, allowing the nose of the seat base frame to buckle downwards, jamming the mechanism.  The repair was straight forward – remove the mechanism, straighten the seat frame, weld the cracks, repaint the frame and then thoroughly clean and reassemble the mechanism.  The gears each have a cup with ten loose ball bearings, or at least what should be loose; mine were stuck fast with the black paint applied after assembly in the factory, so needed a lot of cleaning up.  The result is a very easy to use recline mechanism and the silencing of the creaks.  Just in case you forget during reassembly, both crown wheels on the lateral shaft face the same side as they have to turn the longitudinal shafts in the same directions; the crown wheel nearest the knob cannot be removed from the shaft, so you don’t have to make notes of which way around they are fitted.

I added sections of 1″ medium density foam sheet (£6/metre from Dunelm Mill) to the full underside of the seat base cushion and to the rear of the seat back cushion’s lumbar area, including between the frames and they grooves in the cushions, to rectify their aging and compression, and it seems to have worked well.  I haven’t done any long trips yet, but hopefully it’ll match the comfort of the passenger seat from now on.