Repair Defender Sills and Posts, part 2: Rebuilding


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Replacement Sill, B and C-post assembly ready to fit into prepared position : credit: © Trevor Cuthbert
With the corroded side frame cut away, Trevor finds the replacement is an easy bolt-in fit

Need to know

Time: 4 hours (to fit both sides)
Cost: £1380.98 (see below)
Difficulty: 4 out of 5
Models: Defender 110 station wagon, 110 double cab, 130 double cab.
Tools needed: General workshop tools, trolley jack, drill, impact wrench, riveting tool.
Parts & costs: Left-hand sill, B-post and C-post assembly, galvanised, £660.66; right-hand sill, B-post and C-post assembly, galvanised, £660.66; set of four door latch striker plates, stainless steel, £24.86; two sets fixing kit, stainless steel, £34.80.
Work safely:
• Disconnect the battery before work begins (earth lead first).
• Wear eye protection when drilling and working with flaking metal components.
• Wear tough gloves and eye and face protection when using an angle grinder. Be aware of how aggressively the grinder can twist and kick back in your hands.
• Wear safety boots and gloves.
Contacts: YRM Metal Solutions Ltd, Tel: 01388 488150,

See also part 1: Removing Sills and Posts


Defender 110 and 109in Series-type station wagons have a sill, B-post and C-post assembly on both sides of the body, manufactured from steel. These inevitably show signs of rust as the years go by. If remedial measures are not undertaken, this rust can cause major structural damage to the Land Rover.

Until recently, the main option to deal with seriously rusted sill, B-post and C-post assemblies was to cut out the affected areas and weld in new steel to replace them. Some good repair sections have been developed to replace sections of the B-post, the complete C-post and sections of the sills.

Another option was to replace the sill, B-post and C-post assembly as a complete unit, if you could find a good second-hand one from a dismantled Land Rover.

However, here we’re using newly manufactured sill, B-post and C-post supplied as complete assemblies with no welding required. The assemblies are offered in un-galvanised steel or a fully hot-dip zinc galvanised option, which was chosen for this particular Land Rover.

Last month we showed how to dismantle the corroded assemblies from the vehicle, and now we are about to install the new structures.

Not beyond redemption: This is one of the original B-posts, detached from its sill by corrosion. Rather than repair the sections, the owner wanted new sill, B-post and C-post assemblies fitted.

Offered up: The new sill, B-post and C-post assembly fits straight into place where the old rusty parts had been removed, so their attachment to the truck can begin immediately.

Easy does it: A little bit of jiggling is required to get the C-post section of the assembly correctly in place behind the aluminium body without damaging the profile.

Stainless steel fixings: Getting these two bolts in place through the body floor will prevent the assembly from inadvertently dropping out of position when we work at the front end.

Bring them together: A G-clamp is used to pull the C-post section tightly and accurately against the body panel, and hold it there until it is permanently secured in place.

First fix: Now that we’re happy with the positioning, a 5mm hole is carefully drilled through one of the original rivet holes in the body panel into the C-post section.

Riveting stuff: A series of 5mm pop rivets are used to fix the body panels back in place on the C-post and down towards the sill, just as was originally done in the factory.

Convenience and speed: This is a new piece of kit – a compressed air-powered rivet gun which takes the strain out of riveting, although my old manual riveter is effective.

New and shiny: Working from the rear, towards the front, the floor panels are bolted to the sills using the fixings kit ordered with the sill, B- and C-post assembly.

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Slightly loose at first: The M6 bolts stainless steel sets that fix the floor panels to the sills are tightened with 10mm spanners, but not fully tightened up at this stage.

Adjustment: The sill attaches to the bulkhead foot via slotted holes, which allow for adjustment. Clearly this one needs to be tapped in to the right a little more.

Less fiddly: Included in the fixings kit is this stainless steel stud plate, which is much easier to fit through the bulkhead foot than a pair of M8 bolts would be.

Forcing the issue: The sill was springing out to the left so the flange nuts were partially tightened onto the studs to hold it in position while tapping it into alignment.

Inside matters: The interior trim for the B-post is fitted back in place using the original trim fasteners to hold it in its position along the top of the post.

Bolted back on: The top anchor point for the front seat belts are captive nuts in the B-posts. This can now be attached and tightened up using a 17mm socket wrench.

Final checks: Now that the sills have been fitted to the bulkhead foot and correctly adjusted, all fixings can now be properly tightened up, including here at the seatbox.

Don’t let it drop: This captive nut plate (with fixings kit) is fed through the lower part of the B-post, and manoeuvred to the holes above, where it holds the latch striker.

Approximately located: The captive nut plate receives the bolts that hold the latch striker with its spacer and packing, as needed, to the B-post, tightened using a Torx screwdriver.

Good alignment: The door catch is adjusted to allow the front doors to close with a good shut line, where the contour of the door and B-post line up nicely.

Complete again: The rear doors are fitted to the B-post using the original hinges, while the rear door catches are fitted to the C-posts. After painting, the job’s complete.


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