XR4Ti Archived Tech Articles

    The Fix for a Sticking XR4Ti Trunk Lock Button - A general removal, rebuilding, and replacement proceedure that prevent you from having to use the pull-the-lock-back-out-with-the-key trick.

Post Date:    Fri, 23 Mar 2001
Subject:      Sticking Trunk Lock Fix - XR4Ti
List:         merkurowners@merkurowners.org

I was fooling around with the rear wiper motor in my "racer" XR recently 
and decided to find out why my hatch lock has been hanging up and slow 
to return.  When I took it out and disassembled it, I was amazed with 
how easy it was to fiddle with and clean up.  I know a bunch of you have 
a lock that requires a key to pull it back out just so you can latch the 
hatch.  How do I know this?  Both of my XR's displayed this tendency 
before last weekend.  I'll be doing the second XR soon.

First, take off that trim panel that covers the underside of the hatch off.
That's as simple as popping off the pine-tree trim retainers.  Just make 
sure you collect them all, as they have a tendency to fly a good distance 
when you pop them free.

Second, unbolt the lock solenoid from it's mount.  You should be able to 
move the solenoid around enough to get your arm in the hole where the 
solenoid is.  Then stick your arm in the hole and pull the retaining clip 
off the lock.  Easier said than done.  The clip is shaped like a "U" and 
fits around the lock cylinder to prevent it from pulling out of the hatch.  
It'll have a tab on it that you can get a finger around.  It'll be on there 
reasonably tight.  I know I've got some scrapes on my forearm from when the 
clip came loose.

Now that you have the lock loose, lower the hatch.  At this point you'll 
pull the lock cylinder out as far as you can.  The pullrod from the lock 
solenoid will still be attached.  Work the pullrod out through the hole 
until you can maneuver the lock cylinder in such a way as to slide off 
the end of the solenoid pullrod.  You'll understand once you see it.

You now may have your way with the lock cylinder.

There is a snap ring in place on the backside of the lock cylinder, opposite 
where you put the key in.  You'll actually have to pry this out, as there 
are no holes for standard snap ring pliers.  Take it easy, because this 
holds the whole thing together.  Mine came out with a scratch awl and a 
small flatblade screwdriver.  The assembly (locking plate, snap ring, and 
spring) will pop out with enough force to get lost, so be careful.

You'll see the original lubrication, now likely in the form of a yellow waxy 
subtance and rust, on the locking plate (the part with the little ear that 
connects to the solenoid pullrod) and the spring, as well as the actual lock 

I thoroughly cleaned out the bore of the lock cylinder using some scraping 
tools to get the congealed funk out.  I also removed the little o-ring on the 
outside end of the lock cylinder bore and cleaned it as well.  Make sure to 
reinstall it with the split in the o-ring facing toward the inside end of the 
lock cylinder.

The lock mechanism has plenty of grooves and notches in it that have 
collected funk over the years.  Make sure it's clean.  I also cleaned the 
spring, the locking plate, and the snap ring thoroughly.

I lubricated the assembly very little.  In fact, you might want to ignore my 
advice on lube and do a little research yourself.  I used synthetic wheel 
bearing grease in the groove lands inside the lock cylinder bore.  This seemed 
to make everything work very nicely.

Assembly is straightforward, with the exception of installing the snap ring.  
Just take your time and watch it carefully when it flies across your garage.

Just reinstall it the same way you took it out.

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Published by Chris Anglin.