LX450 Cruise Control Actuator Service
Update 03-12-09: For system TROUBLESHOOTING and high resolution scans from the Electrical Wiring Diagram service manual go here:
LX450 Cruise Control Troubleshooting Guide
The Series 80 cruise control actuator is a very pricy part listing for over US$1400. If you want to try to service your bad unit before investing in a replacement, here's how. NOTE!!!! This is not for the faint hearted! It is very tricky and requires your full attention. If you screw up or lose a part, you are simply SOL - there are NO internal parts available for this device!!!! Figure at least 3 hours to do a complete tear down.
Materials needed
Bearing grease - synthetic. I used Phil's bicycle grease. BelRay would be another good choice. I am sure there is a special actuator grease, but I doubt you could locate the right stuff.
Dow Corning DC-4 or equivalent - silicone dielectric grease. Here's one source: Dow Corning DC4 Electrical Insulating Compound (5.3 oz. tube)
Contact cleaner - plastic safe, NOT brake cleaner.
5 minute epoxy.
Bench vise - 4 inch or larger, with padded jaws.
Miniature pliers, screwdrivers, and assorted compact hand tools.
Patience - lots of it
PROCEDURE:
Open the hood and remove the plastic cover from the cruise control servo. Lift straight up to release the three clips. Remove the Philips head screw from the retainer and take off the cable from the actuator arm. Remove the electrical connector by squeezing the tab underneath (out of sight) and carefully prying with a large flat screwdriver to ease the connector off the actuator. Inspect for corrosion and correct later if necessary. Remove the three 8 mm bolts (12 mm hex) holding the actuator to the fender, and remove the assembly.
Here's what it looks like. Start taking off the extra bits - both black brackets
and the electrical attach bracket. They are all 6 mm (10 mm hex) bolts.
All the brackets are off.
Wash the actuator using a degreaser like 409, rinse and blow dry. Here is a
detail of the spring and arm. There are a lot of parts there.
Another view.
Here's the bottom. Remove the screws and the cover plate.
There are a lot of bits in there. At the top is the white plastic sector gear
that is attached to the output shaft (the one the cable attaches to) and which
also drives a potentiometer to the left. From the bottom of the sector gear
extend two arms that operate the limit switches (These are the contacts that are
supposedly "cleaned" by manually operating the arm several times. Yeah,
right....) To the right is the motor that drives the clutch assembly which is
hidden under the switch plate. The actuator is in the relaxed position here -
compare it to the next shot.
The cable arm is manually forced full travel to the "wide open" stop. Note that
the other switch is now open.
Remove the rubber gasket. It comes all the way off - I haven't yet pulled it
completely free here.
Because the blue and orange wires attach to the motor brush block, we next must
take the motor out. Remove the two motor housing Philips head screws.
STOP! To keep the armature in place it is
necessary to wedge a small screwdriver into the worm gear on the motor shaft as
shown. This allows you to pull off the housing and (strong) magnets without
disturbing the armature and shaft. If you don't take this precaution you will
probably damage the brushes!!!! In the photo the housing has been removed.
The inside of the motor housing. I sure don't see much grease in that bearing.
Close up of the brushes. Sorry, it's a little blurry. The white plastic thing is
the wire connector.
Carefully pull back on the brush "pigtails" to retract the brushes and remove
the armature and shaft assembly. A third hand is helpful. Here the brushes are
lifted out of their holders, exposing the springs. Remove the springs now. Note
the old caked-on grease on the shaft.
Remove
the two Philips screws and the brush plate. Write down the wire colors! - blue
to the top and orange to the bottom of this pic - then unplug the two motor
power wires and lay the brush holder aside.
Unplug the black ground wire and pull out the orange and blue wires.
Remove the three Philips screws and swing the switch assembly up and out of the
way. Underneath you will see a lot of hard grease and the two floating contacts
for the clutch assembly. These contacts ONLY move when there is power on the
clutch - moving the arm manually doesn't do anything here. Above are the two
concentric rings that the contacts ride against.
Remove the small snap ring. This is tricky because it is TINY. I was able to use
a regular small snap ring plier. DON'T let it fly off into oblivion! Remove the
underlying flat washer, wave washer and flat washer. Remove the clutch. In this
pic I've cleaned it up some, but there is still hard grease in the gear teeth...
The underside of the clutch. Note the three drive pins around the perimeter. The
ratchet handle is keeping the contacts from being damaged.
Carefully remove the copper shim/ friction disc (?). It's very fragile. Make
very sure it's super clean when you reassemble.
Remove the lower part of the clutch. Note the holes around the perimeter that
mate with the pins when the clutch energizes.
Back view of the bottom clutch section. More gummy grease!!
Close up of the bottom part showing the shim that goes in the hole.
Originally I wasn't going to remove the small plastic sector gear and
potentiometer, but all that hard grease made me think I should keep going.
MARK THE SECTOR GEAR AND POTENTIOMETER so you can
get them back exactly as they are now! This is critical! The sector gear only
goes on one way because it is keyed to the shaft, but the potentiometer can mesh
in many different ways. Remove the sector gear by carefully prying upward. I
broke off both small retaining clips - maybe you can do better. Don't worry if
it happens to you - just be sure to get the broken bits out. You can epoxy the
gear to the shaft during reassembly. Remove the Philips screws and pull off the
pot and housing.
The large steel sector gear attached to the output shaft. Note the steel shim on
the sector gear and also on the center clutch shaft. The black blob to the right
of the sector gear is a rubber stop bumper. Remove the two shims and flip the
housing over.
Remove the 6 mm (10 mm hex) nut from the shaft and start taking stuff apart. PAY
ATTENTION to the order! There are a lot of parts - remove the spring from the
arm to take away tension and pull off the arms and various washers, bushings,
and spring. The pic is a little confusing - the nut is to the right and the
parts are in order removed going to the left. The two shims removed in the
previous step are also shown.
Close up of the motor shaft showing the two thrust ball bearings that fit into
recesses in the ends. Be careful to not lose these! They are held in by grease
and will fall out if inserted dry. In this pic I have already polished the
armature using crocus cloth.
At this point you are faced with a bench top full of small parts. Clean everything thoroughly to remove the old grease. Blow dry with compressed air if you have it, while being very careful not to blast small parts into the next yard.
Take a deep breath and start reassembling. Grease the parts with the synthetic bearing grease as you go, using a small screwdriver to keep your hands clean. Add enough grease but don't lay it on thick. Be especially careful around the clutch to not get any extra lube onto the mating parts. Use the DC-4 silicone dielectric grease ONLY on the sliding contacts of the clutch, and nowhere else!
Reassembly is the reverse of disassembly. When you get to the point of installing the motor you will run into a glitch:
Cut out a small strip of thin cardboard or index card to these dimensions.
Wrap the cardboard around the inside diameter of the brush plate, so that it
holds the brushes fully retracted against their springs. It's not real pretty
but it works.
Ensure that the two thrust ball bearings are in place in the shaft ends!!
Work the lubricated shaft past the cardboard, then remove the tool to release
the brushes. It takes a bit of fussing - use a small screwdriver to help shape
the strip if necessary, and twist the shaft as you push. Wedge a screwdriver as
before into the worm gear to prevent the shaft from getting sucked out by the
magnets as you install the motor housing.
If you broke the plastic sector gear tabs, install the gear, degrease the parts and add a small blob of 5 minute epoxy and allow to cure before proceeding. Make sure it doesn't extend above the shaft or it may contact the cover.
Reinstall the actuator and cable, and lube the cable end where it attaches to the arm. Install the splash cover and go for a test drive. Hopefully it will work, if not.... too bad. Mine worked fine. It also felt smoother when operating it by hand due to the fresh lube.
NOTE: if you want to try to "clean the contacts" by manually operating the arm, be aware that moving the black arm does practically nothing!!!! You must move the underlying silver arm to actually move both switches open and closed! This should be clear after having seen how the arm goes together. The glop under the clutch can't be cleaned in this manner.
Page Updated 03-12-09