DIY Starter Motor Rebuild

This write up focuses mainly on rebuilding the starter. Removing the starter on this vehicle is actually very easy assuming you have some extensions and 15mm swivel sockets. There are several other DIYs showing how to remove the starter, so that will be excluded from this write up. 1. Here is our starting point. On cold starts, my starter gear would not disengage quickly enough and make a godawful noise. I gave the mechanism a quick visual inspection to make sure nothing appeared to be damaged. 2. We will start by removing the motor housing. You will need to remove these two 7mm hex head screws and the 13mm nut holding on the ground wire. 3. We will now need to remove what I'll refer to as the "plunger assembly". I will pretty much garuntee that you will need to bust out your drill bits to remove these screws. You can either drill the heads off, or use an extractor. I opted to use an extractor, which removed them with no drama. You'll want to order new 5mm flat head screws. Overall length is roughly 33mm. 4. Once you get the plunger assembly housing off, this is what you'll end up with. By this point, it should be a little more clear on how the gear disengages. Don't loose the little rubber L piece! 5. I started by cleaning the plunger assembly and re lubricating it. All of the grease on my plunger was solidified and was "sticking." I cleaned off moving surfaces with brake cleaner and used high temperature grease as replacement. 6. I'm using Mobile SHC 220 high temperature grease, since it's what I had. What's important here is that you don't go crazy with the grease. Less is more, and a light film is all you should need. 7. Moving onto the planet gear assembly. If the "cap" for it is still stuck in the motor housing, you can remove it using a 90 degree pic. If your cap came out with the assembly like mines did, you can lift it straight off. 8. The ring gear has three rubber feet that friction fit and can be easily pried out. I gave this a good cleaning with brake clean and wiped out the teeth. I repeated this process with each of the planet gears, gun gear (which is inside the motor housing), and the planet gear carrier. 9. I did not disassemble anything beyond this. What I did for this spline area was wipe it as clean as I could get, then reapplied a new moly grease. 10. The last place you'll want to clean and add a little bit of grease is at this nose cone. I cleaned out the dried up white lithium grease and applied a very light coat of grease. Just enough so that the lip seal isn't going to get torn up on a dry shaft. 11. By this point, everything should be ready for reassembly. For reference, this is what my planet gear assembly looks like after regreasing. You don't want to pack this with grease, as there is a brushed motor in the housing. There is no seal between the planet gears and motor. You may want to add a light coat of grease to the motor shaft as well. 12. To reassembly, I recommend that you put the long screws through the body of the housing, and use it to keep your mechanism aligned as you put everything back together. Here, you can see the threads of the screws protruding through, and the note the notch on the starter housing. The notch needs to align with the rubber L. Make sure you install the plunger assembly before sliding the motor housing on all the way. You will not be able to get the plunger into the fork lever if you install the motor housing first. 13. Here is everything back together with the new fasteners. Here are the fasteners I ended up using for the plunger assembly.

Very nice write-up and pictures. Hope it works well when you get it back in the car! My first starter replacement was because the motor would sometimes strand me once it got heat soaked. So I replaced it with a Bosch re-manned starter to save a bit of $. Well that turned out to be a mistake because roughly 18 months later the whole end of the starter housing busted. So, replaced again with a brand NEW Bosch starter I got off Amazon. Been good for about 4 years now. I DD so my starter sometimes gets hit 5-6 times a day almost everyday. Thanks for the write-up!

Nice write up! Can we assume that everything works perfectly again? How much total time are we talking about? Did you need to do anything electrically to the motor(s)? Brushes?

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Yes, that's a safe assumption as she started right up without any issues. I did not touch the brushes. I was mainly in there to go after the cause of the terrible start up noise. So this is more of a half baked "rebuild." I believe to get to the brushes, you'll want to remove the two phillips screws on the back of the motor. It took me about an hour to remove/reinstall the starter, and about another 1.5 hours to do the starter. Starter time is a little inflated since I tried to document what I was doing. I would just round up and assume a 3 hour job if you don't run into major issues. The trick to getting starter in and out quickly is a 20"+ extension and swivel socket. I used locking extensions, since it sucks having a socket fall off when you're working in confined spaces. Pricy tools, but totally worth it. When the two bolts are out, don't try to bring them out on the end of the socket. Leave them hanging there, and reach in with a magnetic tool and remove them that way. I also removed some of the small vacuum lines to avoid damaging them when pilling out the starter.

Quotes source post: 15698582

Car fired right up. :-) Wow! I've never heard of of a starter failing like that. Usually goes more along the lines of hitting it with a hammer and it still didn't work.

Nice write-up and photos