After the long weekend of turkey and tequila, it is time to rebuild the starter on my '61 GMC. The starter is off my GMC 305 V6. It needs a rebuild since it "binds" when trying to start. These steps are similar to other starter rebuilds, so I hope this helps some people out. Let's get started: I bought a starter rebuild kit and starter arm kit from NAPA. Little did I know that the brushes, hardware and drive in this kit were the wrong ones . Nevertheless, here is what comes in a typical kit: Begin by taking apart your starter. Remove the pin that supports the starter arm. My starter used a pin/snap ring. Take the arm/weight assembly out. Drive the roll pin that holds the weight to the arm. Here I used a socket clamped in a vise for support. Use the appropriate sized punch and hammer the roll pin out. Next, use an appropriate-sized socket to remove the drive-end bushing. For the commutator-end bushing removal, I am using a pick and hammer to collapse the bushing inward, whereupon I could remove the bushing with needle nose pliers. You could also use a bottoming tap to remove this, but I didn't have one. You could also buy the dedicated tool for this if you're feeling saucy. I am now using my multi-speed dremel tool with a sanding wheel to remove any burrs from the removal process. If you do this, use the LOWEST speed setting. You just want to knock out any burrs. Do not increase the ID by excessive sanding.
Clean the starter housing in a parts washer or similar. Get your new bushings, coat with a little bit of motor oil (a little dab 'l do ya) to ease installation. Drive the bushing in first with the hammer, then drive it home with a socket. Repeat for the other bushing. Now for some cussing & fun, install the new arm and roll pin to the weight. What I did here was clamp the weight in a vise. Put a small strip of duct tape to prevent the weight shaft from rotating (tape is hard to see here). Use channel locks to start the roll pin, like so. Once you drive the roll pin as far as you can with channel locks as shown here, use your punch/hammer to drive the roll pin as it was before. Put a dab of grease (I like using moly) on your new pin/bolt for the arm. The grease lubricates the pivot point. If your new arm kit uses a pin/snap ring, then install it. Otherwise, put a dab of blue loctite and tighten the pivot bolt nut. Now that this half of the starter is done, put it aside.
Now we're going to tackle the armature. Here's the exploded view of mine: Clamp the armature GENTLY in a vise. Use rags and clamp it just enough so it won't fall over. Use an appropriate-sized socket to drive the retainer off of the snap ring. My manual says to use a 1/2" coupler. Rap the socket/coupler with a hammer lightly to knock the retainer from the snap ring, like so. Next, you need to remove the snap ring. How you choose to tackle this SOB is up to you, but I was able to remove it with two thin-blade slotted screwdrivers. Use them to "walk" the snap ring up the shaft. Take your time and try not to poke yourself too many times Another tip: use a rag to cover the end of the shaft so the rag will catch the ring and it won't fly across the garage. Take your time and perform this step sober ahahaha Remove the retainer and snap ring and inspect them. If they're not distorted, they can be reused. Replace if they look crappy. Remove the drive from the armature shaft. So at this point, I have ordered new brushes and drive from rockauto. Stay tuned next week for the final part of the starter rebuild.
Soon... I had another hiccup with ordering parts. I have everything now, will for sure get it going this weekend. I will also include some armature tests with a DVOM, since I don't have a growler
Okay, here is the final part two of the starter rebuild. I apologize for the delay; let's not get into the errors on NAPA's website. Without further ado... Support the armature shaft on your vise. I am using a v-block here. Clean the armature shaft of old oil and grease. Clean the commutator bars with scotch-brite and contact (electrical) cleaner. Since I do not have a growler, we can perform a few checks with a DVOM to see if the windings are OK. First, set your DVOM to the lowest resistance setting. Probe two commutator bars 180 degrees from each other. Note the resistance value. "Walk" your probes all around the commutator and note the resistance values. They should be close to each other. Next, check each adjacent commutator bar. Again, note the resistance values. They should also be close to each other. In the case of my armature, my values ranged from 0.6 - 1.1 ohms. Any abnormally low resistance value indicates a short. Any abnormally high resistance/no continuity value indicates a break in the winding. A more detailed explanation of the test is given here: http://www.groschopp.com/how-to-check-a-motor-armature/ Finally, clamp a probe to the armature shaft and probe each commutator bar. There should be no continuity between the shaft and commutator bars. If so, you have a short.
If your armature windings check out OK, then we can assemble the rest of it. Support the armature in a vise, and apply clean engine oil on the spiral grooves. Apply oil to the drive bushing. Install the assist spring onto the shaft (small end towards armature) and slide the drive on. Clean all of the shaft hardware. Slide the retainer onto the shaft, cup-side towards end of shaft. Place snap ring on shaft. Use an appropriate-sized socket and hammer to start the snap ring on the shaft. Use a screwdriver to "walk" the snap ring towards it's groove. Be careful to no deform the snap ring. Use two pliers or channel locks to lock the snap ring to the retainer. Install the thrust collar on the shaft, shoulder towards retainer. Make sure the retainer and thrust washer have a light coat of oil. Now that the armature is assembled, put it aside.
Now let's focus on the starter main body. Clean the body with rags and brake cleaner. Don't use a parts washer since the solvent could affect the field coils. Use contact cleaner to clean off the brush holders. Remove the brushes, noting orientation. An offset screwdriver helps. Use contact cleaner to clean the brush holder and terminal. Install the new brush, noting original orientation. Tighten snug. Repeat for other three brushes. Now let's check the field coils. Grab your DVOM and set to minimum resistance, just like we did for the armature. Set the shunt connector aside (the small wire lead) and clip a probe on the main field coil lead, as shown. Probe each insulated brush terminal (not the other ones which are connected to the motor case). There should be very low resistance. Any high resistance/no continuity indicates a break in the field coil windings. Last, clamp a probe on the case of the motor. Probe the same insulated brush terminals. There should be no continuity. Any continuity here indicates a short in the field coils to ground. If this checks out, let's move on to final assembly. Put some engine oil on the end frame bushing. Put a skim coat of grease on the drive collar, where the arm contacts it. Support armature on vise. Install the end frame on the armature. Ensure the arm engages the drive collar properly. Flip the armature/end frame assembly and clamp the end frame on the vise. Install the starter body over the armature. You'll need to finesse the brushes onto the commutator. Oil the leather oil wick washer. Oil the end cap bushing. Place the wick washer on the end of the armature shaft, oily side facing the end of the shaft. Install the end cap, align the screws and tighten. Finally, install the solenoid assembly. After this, bench test your starter with a fully-charged battery. Engage at least three times, to make sure everything functions as it should. If all is well, bolt it in, wire it up and try it out on the vehicle. Listen for any weird noises (grinding, etc.). If OK, crack a beer and test drive! (Not in that order...)
Thank you for the very well written, and thought out tutorial....very easy to follow, not confusing in the least.
The Jalopy Journal
