RESTORING THE INSTRUMENTS

When trucks have sat unprotected for many years, the faces of the gauges and other instruments tend to fade, peel, and degrade. At some point, you have to make the decision to pull the gauge cluster apart and set things right. Like other things that you only do once in your life, it's a pretty scary proposition to tear into some of these parts. The only compensating factor is that they weren't going to work anyway, so how much worse can you make it?

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Over the years, I've spent a lot of time haunting the halls at the Reedsville and York, PA swap meets. Digging through the bottoms of the cardboard boxes of junk, I've found a number of NOS instruments for the M5 trucks and bought them at fair prices. This gave me the confidence to destroy the faces of some of my old gauges, knowing that I had decent replacements. I removed the tiny screws from the faceplates and put the plates on my scanner. I used the images as templates in a graphics program to recreate the markings on the gauges. Then I printed the files out on special decal stock user a color laser printer.

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I stripped the paint off the old faces, repainted with Premium Decor brand decorative spray enamel PDS-16 Almond from the local True Value hardware store. It is a glossy paint; however, decals stick better to glossy paint and you can overcoat with a clear matte finish. You may find some other light almond that appeals to you or is locally available. Paint the instrument mask with the same almond paint. I was satisfied that the new paint was very close to the NOS gauges that I bought.

You can obtain a Deluxe Decal Finishing Kit #82400 for $16.95 plus shipping from Micromark (www.micromark.com). The kit includes special solutions to make the decals stick better and to lay against the surface better. There are also overcoat solutions in the kit. See their 82400 instructions on the web site. Alternatively, buy a spray can of Krylon clear acrylic spray in matte finish, #1311, to overcoat the decals. The Krylon spray is available at hardware stores and art supply stores.

Let the almond paint dry for a few days. Cut out each gauge pattern around the black outline. Then cut out just the markings that you need as tightly as possible to the marks themselves. You will need to leave some clear areas to join the marks together to maintain spacing.

Lay the remaining part of the gauge decal on the gauge plate to see where to position the markings. The positioning of the markings is just a little different on each gauge. Trim the guide decal to go around the pins so that the paper can lay flat against the plate. The gold area over the odometer opening is just to help with alignment, not for application to the speedometer, so you may cut it out as well.

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Dip the decal markings in water for about 10-15 seconds, then let it sit for a minute, just enough to let the decal start to slide on the paper. Immediately slide the decal onto the gauge plate and position it using the guide piece held just off the surface of the plate. Wipe any remaining water with a clean Q-tip or paper towel. Be gentle!

Allow the decal to dry overnight. If you bought the Micromark kit, apply the decal softening solution 2 or 3 times to flatten any air bubbles or raised edges. When dry, coat the decal and entire plate with the matte finish acrylic spray. Only a light coat should be needed. Let the acrylic dry another day before reassembling the instruments. You may want to practice the decal application and spraying by using the extra lettering on the decal sheet on a painted piece of scrap sheet metal.

Here are the restored faces compared to an old gauge and also to a new old stock (NOS) gauge.

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You may also want to replace the diffusers around the instrument lights. These tend to shrivel with age. Use heavy weight, diffuse mylar drafting film to make a new cylinder to slide into the lamp opening. The faceplate was produced by an "etch-and-fill" process. If the gold numbers and letters on the glass are gone or are peeling, you'll need to re-do the glass. Wash off the remaining numbers while scrubbing the glass with a fiber brush using Spic and Span, Oakite, or some other strong detergent. Rinse well and let dry. Clean again with Windex and a soft cotton cloth. Paint over the etched areas with gold paint (Krylon "Short Cuts" or similar), then shave off the excess with a single-edge razor blade.

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The same techniques for painting, application of decals to instrument faces, and top coating apply to the odometer wheels. The decals are much more difficult to apply to the surface of the drums, however. In addition, the alignment of the numbers around the edge is critical.

The tools of a watchmaker would be particularly useful for working on the speedometer and odometer. In particular, an eye loupe of about 6X that stays in place by itself or a big magnifying glass on a movable arm may be needed so that you can see small parts and work with both hands at the same time. Small jeweler’s needle nose pliers, screwdrivers, flat tweezers, Exacto knife, and artist's paint brushes are needed. The whole process will be a test of your patience and your ability to have a steady hand. Don’t rush!

Lay the cluster on a large clean area. Pick a place that you can spread things out undisturbed for a few days or longer – this is not an afternoon’s quick job. Remove the speedometer from the cluster by removing the two screws on the back of the speedometer. Gently pull the needle off by grabbing it with your fingers at the hub. Put it somewhere safe. Take off the faceplate by removing the two small screws at the lower edge of the plate. Follow the instrument decal directions for stripping and painting the plate. Write down the mileage.

To remove the odometer wheel assembly, use needle nose pliers to pull the clip on the left end of the shaft. With tweezers or a small screwdriver tip, push the brass bushing at the left end of the shaft to the right so that it is free from the left bracket. You can now tilt the left end of the shaft up to remove the drum assembly.

Have a small container with lid ready to stash the little parts (Tupperware is good). Remove the drive gear and spring from the right end (tenths wheel). With the left end of the shaft pointing up, pull the inner clip from the shaft. The drums are now loose and can be slid off the left end of the shaft.

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Hold the assembly close to the table so small parts don’t drop out and get lost. Even better, do this over a container. Hold the tip of the separator between the 10000 drum and the 1000 drum with the end of your finger and gently slide the 10000 drum off the shaft. Then slide the separator off the shaft and lay it down with the pinion gear facing up. With a soft #2 pencil, label the separator as “5” and also label the drum as “5” on the side of the drum inside the teeth. Keep the pinions on the separators. They come off easily, so don’t lose them! Note that the top of the pinion gear has three lobes and that the bottom has five teeth. This is how you can tell which way to put them back if they fall off the pin. Later, you will want to put things back in the order they came off the shaft. Repeat the removal and labeling process for the other four drums and separators. The tenths drum is permanently attached to the shaft.

Now sharpen the pencil, because accurate marking is required for the next step. With the wheels lying flat, as in the picture above, turn the wheels so that you can see the 0 (zero). On the flat surface of the drum, make a mark running from the inner hub towards the outer edge of the wheel that is aligned exactly with the top of the “0”. This is important because later you need to line up the “0” on the decals with this mark so that all of the drums will be aligned correctly. If you choose, you can use a scribe to make this mark. On my wheels, this line ran into the space between two of the teeth on the drum as an additional aid to alignment. I also wrote 0, 1, 2, 3, etc. around the flat surface just inside the teeth to indicate the approximate alignment of the other numbers and to remind me which direction they ran.

Now comes the test of your commitment – it’s time to strip the paint off the drums. I’m not sure of the drum material; it is either zinc or aluminum. In either case, don’t use oven cleaner or anything containing lye (sodium hydroxide) to strip the paint because it will eat the metal. The kind of stripper made for aluminum aircraft should work. I just used 220 grit emery paper and took the outer surface to bare metal. Go slowly at this because you don’t want to round off the edges of the drums. Try to sand where you see paint and quit as soon as the metal comes through. Also, be sure not to smudge or wipe off your pencil marks.

I took a couple of 2”x2” squares of �” thick pine, put a 1/8^th inch hole in the center, and used an 1/8^th inch drill bit as a temporary axle for the drums. You can stack the drums tightly together for spray painting, but mask the end of the top drum. Put masking tape around the shaft of the tenths drum and also mask the exposed end of the drum. Give the drums a light coat of primer and finish with the light almond paint (spray can of Premium D�cor PDS-16 Almond from True Value Hardware). Even the tenths drum gets painted almond, as the decal will provide the red-brown background and the almond numbers will appear through clear areas. Let the paint dry for 2-3 days, at least.

Now the drums are ready to apply decals. Get a couple of artist’s brushes. One small brush with short, fairly stiff bristles is good for pushing the decals around. A very soft brush is good for applying the various solutions. You will need a small bowl of water to dip the decals in. I put in one or two drops of liquid dish detergent to help the decals “wet” and to pre-wet the surface of the drums before applying the decals. If you have the Micromark decal finishing kit, there is decal setting solution to pre-wet the drum surfaces.

Start with the 1, 10, 100, 1000, and 10000 drums and leave the tenths drum for last. You’ll need the experience. Take the numbers decal sheet and trim out one column of numbers. Don’t cut the next column until you have finished the first drum so that experience can guide you as you go. At the bottom below the “9”, trim to the small hash mark. At the top, trim about one mark width above the hash mark. On the left and right, trim as close to the numbers as possible. The finished strip should be just narrower than the width of the drums and the hash marks should have been trimmed off.

Be sure that your hands are now very clean – no oil, etc. You may want to make a small mark with a pencil on the side of the drum right out by the edge where the top of the “0” needs to be. This will be an extension, if you will, of the line that you drew on the drum earlier. Don’t mark the outer surface of the drum. Dip the decal strip in the water for 10-15 seconds, and let it sit on the table for 1 minute. Pick up a drum using your left hand with your thumb tip on the smooth side of the hub and your middle finger on the side with the teeth (assumes you are right handed; reverse for lefties). With a soft brush, paint some water or decal setting solution on the drum surface.

Now gently slide the decal up on the backing paper so that about half of the zero is off the paper. Line up the top of the “0” with the mark on the side of the drum and press down at the top of the decal strip with your index finger to hold it in place. If it isn’t right, immediately lift the decal off and place it again. Get the rest of the strip oriented so that the strip will wrap around the drum without walking off the edge. This is not easy to do, and you have to work quickly at this point. With a little pressure on the top of the strip to hold it against the drum, slide the paper out from behind the decal as you turn the wheel. The decal will wrap itself around the drum so keep turning the drum as you pull the paper. As long as most of the decal is on the drum and there are no kinks, don’t worry about exactly aligning the numbers side to side as you lay the strip down. Sorry, I couldn’t do this and take pictures at the same time.

Use the sides of stiff and soft brushes to move the decal around to get it on the wheel surface and free of air bubbles and ripples. Don’t poke at the decal, it’s fragile. If you tear the strip, you can maneuver the edges back into place. This is where the eye loupe may be needed. Keep the decal wet to move things more easily. You’ll find that the decal can move a little side-to-side, but is very difficult to move around the outside. The initial placement has to be right.

None of us have done this before and practice makes perfect. Don’t be concerned if you make a mess at the beginning (or later) and ruin a strip. There are enough strips in the set for a bunch of extras. However, if you decide that you can’t move a decal around enough to suit you, peel it off immediately because it only has to dry a little to be impossible to remove. Then you sand and repaint and start again. You’ll find it easier as you do the five drums.

TENTHS DRUM

Finally, now that you have some experience, it’s time for the tenths drum. As you learned from applying the first five strips, the ends may butt, overlap, or leave a gap, depending on how you trimmed the top and bottom. For the tenths wheel, you want to plan for just a slight overlap so that no white mark occurs. Cut out the dark colored strip. Trim it right to the edge on the right side. The left side needs to be trimmed to cut off part of the dark area. Ideally, you should leave about the width of the stroke of the numbers as the left margin. You can trim off a little more than this to make the alignment task easier if you will tolerate just a little almond showing on the edge of the drum. At the bottom, trim about a stroke width off the dark colored strip. At the top, trim to the edge of the dark color. The goal is to have a perfect butt or a slight overlap in the dark area between the 9 and 0. A wrinkle along the sequence will make the strip length come up short, so try to avoid them and brush them out as you wrap. If you wind up with a small almond gap, though, I doubt that anyone will ever notice (except you).

As with the other drums, dip the decal, wait 1 minute, pre-wet the drum surface, and slide the decal on. On this drum, the right-to-left alignment is more visible, as the almond background is exposed if you are too far to one side. Keep everything wet, work quickly and smoothly, and brush out the bubbles. If you cut the strip a little wide, don’t worry about a little bit hanging over the edge of the drum, you can trim it off with the Exacto knife or razor blade when the decal is completely dry (next day).

Once the decals dry, you can use the Micromark decal softening solution to get the edges to lay flat, shrink wrinkles and bubbles, and get the decals to conform to the surface. Let them dry for a day, then brush or spray clear acrylic over the surface. I used the satin finish acrylic solution. Allow all of the drums to dry for a day or so before you start reassembly, because you must handle them a lot.

REASSEMBLY

The task now is to reassemble the pieces in the same configuration as they were originally. You numbered the parts to make this easier. If your truck or car had high mileage, you may want to swap the 10000’s drum and separator with the 1’s pieces and also the 1000’s drum and separator with the 10’s pieces. I just felt more comfortable putting the same pieces back into contact with each other.

We’ll assume that you are going to go back to the original mileage setting. Carefully slide the first separator on to the shaft being sure the pinion gear is in place. It should completely nest into the tenths drum with a little back and forth rotation. Slide the first drum on. The tips of the separators should be facing towards you as you look down on the drums. Place all of the separators and drums on the shaft, keeping the tips toward you and lining up the numbers. It is easier to assemble if the drums are not at the point of changing from 9 to zero and turning the next drum through the pinion. A small, thin strip of metal pushed into the gaps of the tips can be used to establish alignment as it will be when the drums are remounted in the speedometer. Picture how the tips will drop into the bar and where you will be seeing the numbers through the mask in the speedometer face.

When all of the parts are on the shaft, slide the inner clip in place in the groove in the shaft. Slide the brass bushing on the shaft with the small diameter end facing left. Put the spring and the drive gear on the right end of the shaft and engage it with the tenths drum. Place the right end of the shaft in its hole in the right bracket and lower the left end of the shaft through the slot in the left bracket. As you lower the left end of the shaft, slide the tips of the separators onto the bar at the bottom of the speedometer frame. Push the bushing to the left so that it fits into the enlarged gap in the left bracket. Install the outer clip in its groove.

With a great deal of luck, the numbers will be perfectly aligned and read exactly what you want. Practically speaking, they probably won’t. Be sure to place the speedometer faceplate over the odometer to make sure the whole row is correctly aligned for viewing. It is possible to have the whole row of drums one tooth off when you do the visual alignment. This means that you go back, pull the outer clip, push the bushing to the right, pull the drum assembly, remove the inner clip, and start manipulating the drums and separators. But, before you move anything, note carefully the number alignments. Are you half a space off of less than that? To realign the numbers, you need to move the drums apart enough to disengage from the pinions, turn the drum, and push things back together. Frankly, you may need to do this a dozen times to get it exactly aligned and reading correctly. I don’t know a short cut. If you learn one, tell me so I can share it.

Through the alignment process, it’s a good idea to spin the speedometer input by hand to be sure that the tenths drum turns and rolls the 1’s drum over. The numbers should stay in alignment and the gears should not lock up. It’s probably a good idea to try out the roll-over process on a couple of drums during the reassembly so that you get the feel of proper pinion engagement and alignment. Just don’t force anything to turn. If it locks, slide it apart, rotate the drum a bit, and re-engage it.

When the speedometer and odometer are together, remount the speedometer frame in the cluster, put on the faceplate, and put the needle back on the shaft. Be sure to seat the needle completely so that it doesn’t come loose at a later date. Put the mask over the cluster, put the glass on, lay the paper gasket in place, and put the stainless steel outer cover in place. Pinch the outer cover over the cluster body to retain it. You’re done!

Send me an email if you would like to order decals for the instruments, odometer, or both. EMAIL

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