Joined: November 24, 2008
Location: Oklahoma City
|Posted: Tue May 31, 2016 11:12 am Post subject: Type 4 and late type 3 gas flap cable rebuild tutorial
|ALL TYPE 4 CAR OWNERS NEED TO DO THIS....NO MATTER WHAT CONDITION YOUR CABLE IS IN RIGHT NOW!
I made this “how to” pictorial because this is one of those type 4 only parts that is REALLY hard to find. Virtually impossible to find new…and hard to find serviceable in a junkyard…and they WILL ALWAYS have issues….sooner or later….so fix it now!
When they break or stick or do not work properly... they will not stop you from driving the car but will drive you crazy, it looks horrible driving with the gas flap open and eventually will cause your gas flap to get bent or broken…because anytime you are not driving at high speed either your flap hangs wide open..…or very common…the flap stay closed but cannot be opened without a screw driver or pulling so hard on the flap cable that you break the knob or damage the cable.
So this is one of those type 4 religion things..…that if you are looking for a 1-3 (maximum) hour project on a Sunday….you would be a fool not to do this procedure……because it will repair a damaged cable assembly you have…and/or will make sure this part lasts virtually forever on your already working cable assembly.
The Goal here: to repair the unit (if needed) and lubricate this unit PERMANENTLY….so you don’t have to keep opening it or risk destroying it with time.
Tools and materials you should have or will need:
A small vise or clamp.
Vise grip pliers
Caliper for measuring
An electrical connector crimper that has a space large enough for coaxial cable (optional)
Small files or needle files (note…if you do not have a Dremel tool the whole project can be done with files but will take about an extra hour)
SuperLube synthetic grease
Automatic transmission fluid oil (about ¼ ounce or less)
Exacto or sharp box knife
A flat faced 1/8” punch
A number 55 drill bit (.052”)
Dremel tool with thin cut off wheels and ½” sanding drum attachment
Cordless drill (optional).
A length of steel rod of 0.180” in diameter (if you need to make a complete new cable and have to replace the ball on the flap end)
A length of 0.150” steel rod (to make a replacement cable stop on the pull handle end of the cable). If you can find 5/32” rod at the Home improvement or hardware store this can be sanded down lightly to fit fine.
NOTE: Most cheap 3/16” steel rod works out to about .180” in diameter so I bought one foot of that because I can use it to make both ends of the cable stops with
FIRST THINGS FIRST:
Trust me on this!
Use the lubricants I tell you to. Don’t get creative or lazy.
No matter what, use a synthetic grease in the latch box end. Do not use a petroleum based or lithium based grease that will turn to crust in 3-5 years.
You only get so many chances to re-crimp the lid closed before there is no more lip to crimp with. You cannot solder or weld this material. So lubricate it permanently the first time.
What you want to avoid is using a grease that does not flow well in the coldest weather (almost all normal greases). It needs to lubricate and not get sticky or turn crusty with age. In the worst case….you can use silicone dielectric grease or distributor grease. Those are a bit stiff in the winter but will never get crusty over time.
Best product I have found….use SuperLube brand synthetic lubricant. In the USA you can buy this at any Harbor Freight in 4oz tubes,
Also many FLAPS sell 4oz tubes of this on the sealer and aisle and some FLAPS especially NAPA sell it outright in tubes and tubs as well. Its Teflon based…high drop point but stays creamy like petroleum jelly down to about -40F. Superior to anything out there for specialty uses like this.
For lubricating the cable sheath…do not use ANYTHING but Automatic transmission fluid. It’s virtually rustproof, it stays in oil form forever and never goes away. I have found nothing better for all of the cables on these cars. Mine have been lubed with ATF for over 25 years. Oiled once….they move like butter still. Trust me on this.
Do NOT ever use WD-40 or a silicone based spray oil or general purpose household oil. It will eventually gum up or go away.
The object is to repair and lube…for LIFE…because you cannot afford to break or wear this part out, they do not grow on trees.
The difference in type 3 and type 4 cable assemblies:
While the late type 3 cable uses virtually all the same parts…..it is nowhere near the same length. So…you can rob parts from broken (or new... ) type 3 cables….but you cannot use them as is. Don’t worry…it’s just a type 3….they grow on trees ....comparatively…
This is a type 3 cable assembly
This is a pair of type 4 cable assemblies…see the HUGE length difference? The type 3 cable assembly will never work…but is ripe for stealing virtually all other parts from. The top cable in the picture is my spare and is missing the ferrule and the cover plate on the flap end. We will be making and replacing both parts from scratch.
So here are the common problems with these assemblies and the causes:
1. Flap will not open:
A. The cable is broken (not very common)
B. Either the flange end on the fire wall is loose from missing screws.
C. The pull knob end ferrule has come unclamped from the fire wall backing plate behind the grommet and the carpet (fairly common). This causes the flap not to open because this cable is essentially just like a bicycle brake cable or a Bowdon tube on a clutch cable.
The outer sheath must be rigidly mounted or the sheath just flexes and the cable does not pull anything.
2. Cable is not broken but flap will not open
A. The outer cover plate over the latch mechanism at the flap end has come off allowing the latch finger to over-rotate so that you cannot pull the cable far enough to open the latch (this is THE most common problem and is a symptom of other issues)
B. The latch finger inner workings are rusted/corroded….very common even when the outer flat cap/plate stays in place…..largely because of what I consider a design flaw.
That flaw..…is a small nicked corner on the plate that is there to allow oiling of the pivot bearing point on the latch finger. But being that this assembly is under the fender right there in the range of tire spray, road salt and snow and ice….the nick that lets oil in also let’s water in.
I found out that if you do not have the latch mechanism cavity packed with grease and water gets in, when it freezes hard the ice expansion is actually what causes the latch cover to crack off and fall away.
3. Everything seems intact but the latch finger stay pulled back and the flap won’t latch shut
A. Either the assembly in the latch box end is corroded in place (common).
B. The cable is rusted in the sheath (not common but it can happen).
C. The spring behind the latch pivot finger is broken (somewhat common but usually due to rust and corrosion.
This is what the flap end latch box looks like complete with the lid in place. Notice the nicked corner on the lower left of the flat cover plate and the adjacent pivot trunnion bearing area.
So to start with, even if your plate is still in place, wedge a sharp, thin screwdriver under the back edge. In the best case you will shear off the little nub (I will show it later on) and slide the cover sideways.
It cracks off the small swaged over segment on the right side and allows the plate to pop off. It will scar the edge up just a little but nothing that cannot be filed smooth.
Here is what you see. The finger pivot rises up because there is a spring underneath. If it does not rise up, it’s either gummed up or the spring is broken. The cable with the crimped on ball stop on the end will rise out of the cavity in the finger like this…if the cable stop on the other end is broken off or if the cable is broken.
This is the crimped on cable stop at the knob end.
This is what a complete and normal assembly looks like on the knob end. This cable tube is NOT broken. The bent looking wound spring tube section to the right of the CAD plated ferrule is supposed to be loose and floppy. The knob screws onto that right side end.
Some junkyard assemblies are missing the CAD plated ferrule or barrel….. (Which is very important to the longevity of the cable and proper operation).
The ferrule is sometimes missing because if you cannot reach under the dash to snip the crimp clamp loose that holds the ferrule, many people just pull hard on the cable and it pulls out of the ferrule as long is the knob is unscrewed.
It’s not a big problem because we will build a new one. The new ferrule will not look 100% like the factory ferrule but works perfectly in all respects….and will be unseen behind the carpet.
Plus…..that cable guide ferrule is what the clamp fits around to hold it to the body…so it’s important.
First clamp the knob end of the cable stop ferrule lightly in a vise or a clamp.
With the Dremel tool and a thin cut-off wheel on slow I will cut a slot in the crimped on cable stop just down to but not quite to the wire. I then turn it 90° and cut a second one.
Like this. You can do this with flat files or needle files as well. It’s just a little slower.
When done it looks like this and then just squeeze it lightly with pliers and it splits in two.
And then it just falls off the wire.
Here are the ferrule dimensions for the handle end:
If you feel creative you can make a fairly exact replica of the factory ferrule for the handle end.
In reality a simplified ferrule like this works 100% just as well. The long thin part is just extra strain relief and crimping area but is really not needed.
To continue, pull the wire all the way out of the tube from the flap end.
The spring will come out.
If you need to buy/source a new one:
Spring length: 0.88”
Spring diameter: 0.278”
Spring wire diameter: 0.031”
Ball side of latch finger
Spring side of latch finger
This is the flap locking finger. Notice that at one time it was all CAD or yellow zinc plated.
Inside the cleaned out mechanism box. Note the well the spring locates in. Also note the main dimple on the right that holds the lid down. The nicked corner is on this end. Also note the center divot on the left to align the cover plate. More on this later.
Side view showing the bearing bore for the lever and the notch in the side that the finger protrudes from. You will also note how un-water tight this assembly is.
Making a new pull knob end wire ferrule:
So the first thing I did was take my piece of 0.180” rod and spun it against a Dremel sanding drum to reduce the diameter to 0.150”. Make it longer than needed to start with so you can clamp it in a vise or clamp to work with it.
You can do this very quickly if you have a hand drill you can chuck a short length of rod into and spin it while you run the Dremel sander against it. It takes less than 10 minutes either way.
Make more of this rod than you need. In this way if you drill the hole off center like I did…. twice….it’s simple to just take another piece and drill a better hole. That’s why you bought a foot of rod.
Clamp a short length in the vise. Make a dimple dead center. Drill through it with the 0.052” drill bit on slow with a drop of oil.
Hole in the 0.150” end is dead on
The hole in the opposite end was off so I stated on another piece. Done right on the third try.
I then chucked the rod section into a hand drill and reduced the shank with a needle file. Five minutes.
The finished ferrule.
This is how it fits on the wire.
DO NOT INSTALL/CRIMP THIS FERRULE ONTO THE WIRE YET!
If you are replacing the entire wire/cable as well you need this part:
Make the crimp on ball shaped ferrule for the flap end by taking a piece of 0.180” rod about 0.250”to 0.375” long. Drill the center hole in a vise first. Then chuck the rod into a hand drill and with file and Dremel sanding drums simply shape the outer end into a hemisphere.
Remove the part from the drill and clamp it back into the vise with the rounded end down. Measure and trim off the end with a Dremel and cut-off wheel so that it is no more than 0.180” long. Only the inner end of this ferrule must be rounded like a ball to really work.
The replacement wire:
The original wire diameter: is 0.044”
I would not use stainless as it stretches too much. Best case would be to go to a bicycle shop and source a piece of old brake wire as long as it’s the correct diameter or very close. You can also use very tightly wound steel picture hanging wire. The higher the Lbs./test rating the tighter it is wound.
100 lbs. test minimum looking like this should work. Measure the wire before you buy your drill bits. The hole you drill in the ferrule should be .006” to .008” larger than the wire.
Making a new cover plate:
I provided all of the factory plate dimensions here just in case you want to duplicate it. However I make my new ones without the notched corner so they seal better.
Notch: 0.150” x 0.150” 45° triangle
Materials for pull handle end ferrule and cover plate:
To really simplify and shorten time, a hobby or modeling shop has these items. The strip of stainless plate even though it is only 0.025” thick and only 0.5” wide (0.050” narrower than original) works nearly perfectly. The brass is for making a new clamping ferrule tube.
Original and new brass ferrule measurements:
Study this. The length of the new one will be the same. The only difference is that we will strip away a bit of rubber covering from the cable sheath to fit the new ferrule.
Note that the new ferrule is the same length and the same depth from the handle end opening to the end of the cable sheath. The difference is that in order to fit the right depth into the sleeve, a small amount of rubber covering needs to be cut away. It’s a type of thin rubber hose covering this part. Simply cut around it and it slides off.
Making the new outer clamping ferrule:
The brass tube is large enough for the inner sheath coil to fit in with room to move but not enough exactly for the rubber sheathing of the cable to fit but will work perfectly.
First measure how long the Ferrule needs to be
Mark the brass tube
You can either cut the tube with a Dremel and cut-off wheel….or if you want to spend less than $10 for a tool that will work for a long time for lots of uses, by an Exacto (and other great brands) Extra fine Razor saw with 52 teeth per inch. http://www.amazon.com/X-ACTO-Extra-Razor-5-5x1-1-54Tooth/dp/B0000DD1NF Perfect for cutting soft metal (brass, copper etc.) plastic, rubber and wood. I also have an Exacto miter box that fits my razor saw.
This one is fine but the razor saw blade that comes with it is the coarse tooth one. Even the plastic cheap hobby miter boxes for $6 are great for this.
Cutting tube in Exacto miter box with fine tooth razor saw
Clean straight cut under a minute, deburr when done.
This is another cheap tool I have. Hobby shops. Hardware stores, Walmart all sell these for under $10. This is a grommet tool. I simply tapped the tube onto the end to flare it out. The knob end can use a slight flare too but flare the sheath end out about 30°. Any flared or cone shaped piece of steel will do this fine with a little tapping.
Measure and trim the outer sheath. The outer sheath is actually rubber unlike the sheathing on the floating end piece attached to the nob which is a heat shrink tube.
Notice the fit butting up against the sheath with the flare.
Using any crimper tool that is made for cables of about .250”, lightly place about .75” of crimp length onto the brass while holding the ferrule firmly against the rubber sheathing.
Do not crimp it so far that you crush the spiral wire core. It just has to hold firmly.
Finished ferrule next to original
Making a new cover plate for the flap end:
These are the dimensions again of the original cover plate. As I mentioned I left the notch in there and gave dimensions but I leave the notch out for better sealing when I make a new plate.
Here is the original top and the remake. Notice the locating notch and the fact that the lower stainless plate is slightly narrower which makes the notch look off center.
All I did is cut the strip of 0.50” stainless to length with a Dremel and cut-off wheel. Notice that although it’s narrower it still covers the cavity.
In this view you can see the notch I made with a cut-off wheel and the cast in locating nub for the lid on the right. You can also see just to the upper right of the nub the peened over part that cracked off that was holding the lid down.
Drip in about ½ teaspoon of ATF fluid. Insert the cable. Be sure to put the spring on and the latch finger in the right orientation. Work the cable in an out until ATF appears at the other end.
NOTE: after the cable and sheath sits for a while. Take it outside and swing it around a bit to sling out the few excess drops of fluid. The parts only need to be wet inside. They don’t need to be seeping fluid.
Put the latch box assembly in a vise or clamp to hold it while you work. Pack it full of SuperLube grease. Then insert the latch finger into its trunnion. Push the cable through all the way.
Insert the lid starting with the end opposite the notch.
Hold the lid down tight with fingers on one hand. I also use the same two fingers to hold the punch on the edge of the mechanism just to one side of the notch while holding the lid down. Then strike it lightly with a mallet to dent/peen the soft metal.
That shiny mark just to the lower left of the notch point is the dented/peened area. This is all it takes to hold the lid on.
On the other end of the cable, insert the spring coil that connects to the pull knob. There is a correct orientation for it.
The first picture with the slanted cut end goes into the knob. The one with the straight cut end goes toward the cable sheath inside of the ferrule.
Slip the new ferrule stop onto the cable. The proper distance of wire sticking out is about 1/32”. It is not correct in this picture. Use a piece of tape to hold it in place while you crimp it.
Vise grips work great for this. Start light and work tighter until it deforms enough to grip tight. Then if you have the full ferule, crimp the lower collar as well.
This is why you need either the stock or brass ferrule. Without it…and the strain relief it provides. The knob end rattles around, bends and puts a crimp in the cable end.
If you have not already done it….slip on the new ferrule.
Crimp it on.
I used heat shrink tubing on the exposed loose coil. Then trim to length and install the knob.
The final part is to hold the assembly in a clamp. Apply masking tape. Then apply RTV with a brush or Q-tip to seal and then remove the tape and let dry to seal the box. Sorry for the blue Permatex...it was all I had on hand. I will change it out later for Ultra Gray or black... .
You can use both of three of these pull knobs. They are all type 1 past #’s.
The first hoop style handle (# 111 823 461 A) with the collar near the bottom ,however I would not use unless I could find nothing else. It requires a small "E" clip to go into the slot above the lower collar and fits very loose on the cable ferrule and is problematic on the type 4 cable assembly.
The next "hoop" style I have found here and there and probably was used as replacement...on type 4. It fits fine but was not an original equipment type 4 part. It is part # 111 823 461.
The round knob, is the one that came on type 4 from the factory and is in the parts book as part # 111 823 535 D.
Sorry I forgot the gasket for the firewall. This is a type 3 part #. If you can find one...use it. I have not been able to find them so its just as easy to make one for me.
The one I had was simply cut from 3/32" rubber sheet.
Dimensions for the gasket.
I cut this one from .065" silicone sheet. This is about as thin as I would make it. 1/8" will work but is also about the upper limit. This one looks a little rough because I cut it oversize so I can trim to fit so it stays within the flange lip.
Finished after trimming to fit.
Another little hobby shop tool set that is worth the $20 I spent on them a while back are these precision punches. I make all sorts of gaskets with them. Worth their weight in gold.
I hope this helps. If you have any questions just ask.
Joined: October 04, 2007
|Posted: Thu Jun 02, 2016 7:07 am Post subject: Re: Type 4 and late type 3 gas flap cable rebuild tutorial
|One more impessive documentation Ray!
Lots of your time and effort put into this...unvaluable to us when we need to fix this...MANY thanks!
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Joined: November 24, 2008
Location: Oklahoma City
|Posted: Thu Jun 02, 2016 8:21 am Post subject: Re: Type 4 and late type 3 gas flap cable rebuild tutorial
|Lars S wrote:
| One more impessive documentation Ray!
Lots of your time and effort put into this...unvaluable to us when we need to fix this...MANY thanks!
I rebuilt my spare cable to make this document. I rebuilt my main/original cable...the one not missing the lid from the mechanism end from start to finish in about 70 minutes last night.
I came across one more problem with that one though.....the edge that you would peen over to clamp the lid is just too eroded at the edge to peen over. Others will run into this.
I developed a simple fix for it....while its not beautiful.... it is clean, will be effective and out of sight and will never effect the working of. I will spend 30 minutes tonight and drop that in as an edit. Ray
Joined: November 24, 2008
Location: Oklahoma City
|Posted: Sun Jun 05, 2016 10:57 am Post subject: Re: Type 4 and late type 3 gas flap cable rebuild tutorial
|Update! Supplemental/advanced repair:
So my original cable that still has the original latch box lid…..had issues. There was not enough outer “lip” left to properly crimp the lid on. The lid was “captured”…but could not be held down tightly and there was some leakage.
Yes…I could have simply sealed the gap with RTV/silicone and it was have been leak free, but was at risk of the lid popping off sooner or later.
This is not the first one I have found to be “un-rebuildable” in this way….and I suspect some of you will have the same issue.
So here is a fix for that:
The red arrow shows where the plate is left up on the edge
You can see how just finger pressure closes the gap.
SOLUTION: We are going to screw the lid down.
So mount in a clamp or vise where you can work.
Use the Dremel tool and cut off wheel, or grinder bit or diamond burr to remove the peened over ledge…or you can use needle files.
So when you are grinding away the peened areas of the outer ledge, widen the area you are grinding away to be about 0.1875” wide (3/16”)…..about as wide as the area between the red lines in the photo above …..and file/grind this outer edge to be flush and level with the top of the lid when it is in place. Once the lid is off it should look similar to this.
Then..take a small grinding bur and hollow out a small half circle space on the center line of the surrounding lip and the ledge where lid sits……grind outward. You need a semi-circle of about 0.075” in diameter that is ground level with the ledge the lid sits on. there is clearance for where we are going to drill the holes.
In the middle of these semi-circle or alcoves…on the centerline between lip and ledge…use the burr or a drill bit to put a center starting point for drilling the holes.
The drill bit you will need is a #56 (0.0465” or 1.18mm). The other tool on the left…if you do not already have one is one of the best $9 you can spend.
You can do this with your Dremel but if you have shaky hands…a Pin Vise is fantastic. I have several. This brand is steel has a rotating finger disc on the back and has four different sized chucks for bits from about .010” to about .125”. Great for drilling precision holes in plastic and all kinds of things.
A magnifier…I’m lucky I have just about one of the best lighted magnifier arms in the industry….but any magnifying glass that you can clamp up to work with helps.
The screws I bought from the local True-value hardware store are size 0-80 and are stainless slotted head. The long ones we will use to make a thread cutting screw and the ¼” long ones we will use to hold the lid on.
Buy a few extra of the ½” long screws….as you will need some practice to make a thread cutting screw from one. All of these cost me less than $1. Make sure you get #0 washers with them.
What we are going to be making is this…a thread cutting screw. You will need to lock one of the ½” long screws into a pair of hemostats or locking pliers…and clamp them in a vise. All you need to do is nick the end of the screw on the clockwise turning face …with a cut off wheel at about 5000 rpm.
NOTE: drill a couple of holes in a strip of 1/8” scrap aluminum or magnesium to try the thread cutting screw out FIRST…before using it…to make sure it cuts clean threads. I got lucky and my first screw worked.
Take your Pin vise or Dremel tool and the #56 bit and drill your two holes.
Sorry for the poor picture…I will take a better one later…but once you get a screw that actually cuts threads….use the Dremel tool with cutoff wheel or a pair of wire cutters and cut off the head of the screw.
Mount the thread cutting screw tightly in the pin vise
Now tap your holes. Clean everything up.
Now put the plate on the ledge and mark the plate where the new holes are…and use the Dremel cut-off wheel to notch the plate so that the screws have access.
A few views of the now tight fitting plate and the screws. You can use non-permanent lock-tite of you want, but using Permatex ultra gray which is the stiffest of the ultra RTV’s will probably not let these screws unscrew even if they wanted to.
This is after adding the final sealer.
Joined: November 24, 2008
Location: Oklahoma City