Friday, January 12, 2018

Wiring Harness Problems in Defenders and other Land Rovers



This week we saw a Defender with an unusual problem.  It sat in our warehouse a couple months, and when we pulled it out, the engine skipped as oily smoke came out the tail pipe. It looked like a valve guide or piston had failed but the engine didn’t make noise.



We pulled the plugs and found the left side all wet with fuel.  There was no single oily cylinder. Apparently one side of the engine was grossly over-fueled.

The owner had told us a local tech had changed his fuel pump last year, and he’d asked us to check that out.  He also had a “buzzing” relay under the passenger seat.  Defenders have the injection relays and 14CUX in that location.

With those things as clues we looked at the wiring.  Nothing was amiss from above, but when we unplugged the ECU the problem was revealed. 

Corrosion in a Land Rover Defender engine ECU connector (c) JE Robison

As these vehicles age, the wire harness itself becomes a more and more likely source of trouble  The photo below shows a Mercedes harness where the insulation is cracking off the brown wire.  If powered and grounded wires happen to crumble and touch in the same spot - electrical meltdown or even fire!



Even after I've told you about it, it would be easy to miss the fatal flaw in the wire harness above.  On some cars the wire insulation crumbles and breaks after thousands of heat/cool cycles.  On other cars it breaks after flexing, like on wires that jump from engine to chassis.  We have a Grand Wagoneer in our shop with that problem now.  


The photo above is a closeup of wire harnesses under the floor carpet, typical of most modern cars.  The insulation on these wires looks continuous, but cracks (like in the photo above) and pinpricks from the machinery that pulled the wires in the car factory can let water in, and that will rot the wires invisibly until one day you get a circuit failure.  

Corrosion can attack any car, and it needn’t be a result of heavy flooding.  Tiny leaks over a long period of time can eat into harnesses and cause troubles.  Technicians seldom look to the wiring as a source of electrical trouble but as cars age, it's more likely.


Sometimes the problems are plain to see, like in this Defender.  Other times the wires corrode mid-harness and you can’t see a thing but the signal no longer makes it from one end of the wire to the other.

Solutions to these problems vary.  On the Grand Wagoneer, we can buy some wire harnesses, but not all.  On the Defender, there are no wire harnesses, nor are there new ECU connectors.  Everything has to be improvised or scavenged.  There's no rhyme or reason; sometimes you can get whole harnesses, other times just wire.  Sometimes you can match original wires and connectors perfectly, other times not.  

The takeaway from this Defender:  When you have a group os peculiar problems and no apparent relationship, consider that the wiring goes everywhere.  In this car, the one shop shown in the photo seems to have caused all the vehicle's troubles.   Truly an example of the old adage, "Just minutes to fix it, but hours to learn what to do."

John Elder Robison

John Elder Robison is the general manager of J E Robison Service Company, celebrating 30 years of independent Land Rover, Bentley, Rolls-Royce, BMW/MINI, and Mercedes restoration and repair in Springfield, Massachusetts.  John is a longtime technical consultant to the car clubs, and he’s owned and restored many fine British and German motorcars.  Find him online at www.robisonservice.com or in the real world at 413-785-1665

Reading this article will make you smarter, especially when it comes to car stuff.  So it's good for you.  But don't take that too far - printing and eating it will probably make you sick. 

Thursday, January 11, 2018

Front End Clunks - Bentley Azure and Rolls Royce Corniche

If your Bentley Azure or Rolls-Royce Corniche makes a heavy clunk from the front end the problem may be failed upper strut bushings.  In those cars the struts keep everything centered in the spring/shock assembly.  When the upper bushings fail the shaft of the shock rattles loudly against the top plate for the strut assembly.



You can often see failed bushings from under the hood.  The photo below shows an assembled strut top, and you note two things. First the shock is off-center in the larger hole, indicating the bushing is no longer holding it in place.  Second, you can see a torn edge of the bushing.



The next photo shows what you do about that problem.  It’s a situation where the repair is plainly visible when opening the hood, but fixing it takes all day.  In my hand you see two replacement bushings (note they are different with the one with the collar going on the inside.)  To change these you’ll need the factory spring compression tool, which squeezes the spring and allows the strut rod to be pushed down.


This is what the lower bushing looks like, once the strut is disassembled.  You can see how the round hole has become an oval and the strut is pushed sideways where it bangs over every bump




These rubber bushes are sandwiched between heavy steel washers.  One washer is visible with the hood open, the other is hidden inside the strut.


In the photo above you can actually see how the spring tension pushes the strut rod sideways when the bushing fails. That constant sideways stress leads to early bushing failure and you often get this problem within 20,000 miles.


Rolls-Royce used this strut system from the introduction of the Silver Shadow series in 1965.  On the older cars you could make a short-term repair by installing an aftermarket bushing under the top washer, without strut disassembly.  That worked through the mid-1990s when the Crewe engineers changed to the heavier bushings.

This photo shows the strut in place with the tool installed, from below:


Nowadays we install the tool and clamp the spring.  We lift the spring, bushing, and sleeve out of the fender well, leaving the bare strut in place as shown



We replace the bushing, which is shown inside the spring assembly in this illuminated close up:


The bushing is held in place by a rubber gaiter that covers the top of the assembled strut.  When the strut pulls out from below the gaiter remains inside the spring.  Once changed the spring goes back into the car and the strut pushed through from below.  Then the upper bushing and washer go on and the whole thing is screwed up tight.  Then the spring tool is removed and the job should be done.

© 2017 John Elder Robison

John Elder Robison is the general manager of J E Robison Service Company, celebrating 30 years of independent Bentley, Rolls-Royce, BMW/MINI, Mercedes, and Land Rover restoration and repair in Springfield, Massachusetts.  John is a longtime technical consultant to the car clubs, and he’s owned and restored many fine British and German motorcars.  Find him online at www.robisonservice.com or in the real world at 413-785-1665

Reading this article will make you smarter, especially when it comes to car stuff.  So it's good for you.  But don't take that too far - printing and eating it will probably make you sick. 


Monday, January 8, 2018

A New Old Land Rover 109 goes home

In the beginning, Brad had a dream.  He found a Land Rover out on the Cape, worn out and in pieces.    For thirteen years he picked away at the project.  He found someone to paint the body panels, and stored them in his barn.  He bought a new 109 frame, and stuck some axles underneath.  By and by, he assembled some of the body and set that on the frame.


It looked like a Rover, from the rear, except it was hollow.  Nothing inside.  No hardware, no sound deadening, no trim panels, no wiring, no seats.  No doors and no body in front of the firewall.



And when you got to the front . . . no engine.   But he had an engine!

He had a lot of parts in boxes, some more useful than others.




That was where things stood when we got the call, from one of his friends.  "My buddy has a Land Rover in boxes.  Can you assemble it?"   I told him to bring it out.

The rolling chassis arrived on a trailer.  Other loads brought fenders and doors, glass, and box after box of parts.



Assembly of the vehicle took 1,000-some hours, and included rebuild of the engine, strip and reseal the transmission, clean, service and paint all the driveline components, and a hundred other little details.  The scope of the job went far beyond "assembly."

Some of the mechanical parts he had were wrong, or no good.  Whatever was left needed overhaul or repair.  Many key systems were completely missing.  There was no steering box or linkage.  No heat. No wipers.  The big parts were all easily sourced.  It was the little bits that slowed us down. In some cases we waited a month or more for pieces from the UK, or pieces that had to be custom-made.  That's pretty typical in the restoration world but it was hard for this owner, as he was increasingly anxious to drive his car.  The more real it seemed, the more that became true.

One lesson this truck showed clearly:  Restorers should fit the body together before they paint panels.  This truck arrived with the panels painted, and the client was determined to use his painted parts as they were.  One consequence was doors and other parts that didn't fit very well, and could not be aligned better because we would have needed to cut and shape the underlying structure, would would have required repainting.

This truck included a hodgepodge of Series I, II, and III parts, some of which came from an 88 and some from a 109.  Multiple 109's, most likely.  They all had historic significance to the owner, so keeping them together took precedence over making it all the same or matching some purist's definition of correct.  In that sense, this truck remains true to many others in the field, with decades of vernacular repair with scavenged parts.

Here's the result, one year later.


He had an engine, but it had been left out in the rain. Luckily we looked inside before bolting it in place.  Of course the giveaway was that it didn't turn with a wrench on the crank pulley, and when rolled on its side water came out the spark plug holes.  Hence the full rebuild.


In a funny twist, our machinists found that the original rebuilders put the pistons in with less than .001 clearance.  If the motor hadn't been rusty, it probably would have seized the first time it was started and gotten hot.  As it was, we had enough liner thickness to bore what was there and put it all back together with minimal new parts.

It's also got a new carb, new distributor, new water pump and alternator upgrade.


The truck had axles from an 88, but we tracked down the correct 109 running gear and went through it before fitting with new springs and shocks.  All the steering linkage had to be built also, as did the brake and fuel piping and wire harnesses.

We used dual circuit brakes, the Rovers North harness, and a Kodiak heater.  The exterior is completely period stock. The interior is significantly improved but still looks right.


Defender seats were a major upgrade for the interior.  The owner found this set at a special markdown on the Rovers North website.  We added a locking storage box and reading and overhead lamps.  The basic metal dash remains, as does the bare-bones body interior.



My opinion is that these Defender seats are too high for a Series truck, but the owner is shorter than me, and pronounced his selection "just fine."  If I were doing this for another client, I'd find a way to mount them lower, or raise the roof, or use them in a topless design.  Yet they came out just fine here.

This Land Rover ended up looking pretty sharp, and it's as good as one could wish for from a mechanical perspective.  There is always more one can do on a vintage Land Rover but all the foundational elements are there for this truck now.


It was pretty cool to see what arrived in boxes start and run, and drive out the door.  Getting license plates and an inspection sticker definitely made it real.  This job took one year and two months to complete.  We delivered the truck on a below-zero day the first week of January.  


Its owner is very proud!




John Elder Robison


John Elder Robison is the general manager of J E Robison Service Company, celebrating 30 years of independent Land Rover, Bentley, Rolls-Royce, BMW/MINI, and Mercedes restoration and repair in Springfield, Massachusetts.  John is a longtime technical consultant to the car clubs, and he’s owned and restored many fine British and German motorcars.  Find him online at www.robisonservice.com or in the real world at 413-785-1665

Reading this article will make you smarter, especially when it comes to car stuff.  So it's good for you.  But don't take that too far - printing and eating it will probably make you sick.