How to Rebuild Bosch Starter (SR0408X) 0 001 125 012

DIY - How to Rebuild Bosch Starter Electrical Section (SR0408X) 0 001 125 012

****Thread DIY Under Construction****
There are right ups on how to remove & install the starter on the MKIV cars so please find those if you need assistance with that. This is strictly for rebuilding the Bosch 012 series starter.
I located my parts on ebay but I also noticed several other places, including my local starter rebuilding shop that could supply me with parts. I ended up spending $31 on the solenoid, brush box and rotor bushings. I also found that the solenoid for the Bosch 010 series starters is the same as the 012 series starters. This was much better than paying someone to rebuild it or going to a parts store for a reman unit.
The starting RPM on my starter went from 231 RPM to 357 RPM with what I did here. I also noticed that the nuisance jerking of my engine on start-up went away.
• Parts (search for parts using 0 001 125 012 Bosch)
o Rotor Bushing - Cap End (ID: 0.393” ; OD: 0.554”)
o Rotor Bushing – Planetary End (ID: 0.313” ; OD: 0.438”)
o Brush Box (AS SBH0014)
o Solenoid (DTS 77-27519)

• Tools
o Small Hammer
o Small Flat Blade Screwdriver
o Vice Grips
o Tap that will thread into 0.313” ID bushing
o Impact Driver with Philips Bit
o Scotch Bright Pad
o Vice
o 8mm wrench or socket w/ ratchet
o 13mm wrench or socket w/ratchet
o High Temp Grease
o Electrical Contact Cleaner
o Compressed Air
o Black Paint
1. Remove the nut & lock washer that hold the conductor strap from the brush box to the solenoid. After the nut and washer are removed the strap can be pulled off the stud on the solenoid.
2. Remove the three screws mounting the solenoid to the starter casing. These are philips heads and I found are easiest to remove with an impact driver to prevent from stripping the heads on them. After the screws are removed the solenoid body will come off easily (the spring in the picture is loose). Note that the plunger will not come off with the solenoid body and has to be disengaged from the engagement lever in the housing by pushing the catch of the plunger to the outside of the starter housing and then wiggling the plunger until the catch slips past the lever.


3. Remove the two bolts on the starter cap. They are several inches long. (Do not remove the two philips head screws on the cap as this will save a headache from occurring) Once the bolts are removed, separate the stator housing from the casted aluminum starter housing. The end of the stator/rotor will be visible now as well as the planetary gear set on the cast starter housing.

4. Using a small pick or flat head screwdriver, gently pry the locking tabs on the planetary gear set housing cover. There are three and I unclipped one at a time and the cover came off easily. (Note I had already cleaned and greased this because my starter was squalling on start-up) Next, remove the ring gear and the three planetary gears (the sun gear is part of the rotor).







5. Pull off the stator housing from around the rotor. There is magnetism working against you so it will take some effort, but once past center the housing will come off.

6. Remove the two philips head screws from the starter cap. Remove the cap (note the grease I added?) and there will be a small c-clip that will slide off the rotor shaft fairly easily. Remove the c-clip and washer underneath the c-clip then pull the starter cap off the end of the rotor.







7. The brush box is the assembly just under the starter cap. Pull up on the assembly and it will slide off the rotor. Note, if you plan to reuse the brush box, there are springs in the assembly that will come loose behind each of the 4 brushes. Be sure not to lose them. The brushes on my assembly were in really good shape for 215k miles, but because I had it apart, I went ahead and replaced them.

8. Clean out the grooves on the commutator with a hack saw blade or small flat blade screw driver. Be careful to avoid remove any native material. The idea is to remove all the brush composite and dust/dirt that might be there. I then used electrical contact cleaner to spray the rotor armature and commutator then blew dry with compressed air.







9. Use a fine grit scotch pad to polish up the commutator. The idea again is to avoid removing as much material as possible and only clean the surface for the brushes to make good contact. Once it’s a bright and shiny it’s ready to be blown off again and set aside for assembly.

10. Press the starter cap bushing out of the starter cap using a small socket and hammer. Be sure to note the location in the bore of the old bushing so the new one can be pressed back into the same place. I used a vice to span the cap so the bushing could press all the way out. Use the old bushing and a hammer to press the new bushing into the bore of the cap to the same location as the old bushing was located.

11. Install the brush box onto the rotor. The new brush box will have a spacer to hold the brushes in place so the assembly can be pressed on easily without the brushes falling out of their channels. I used small zip ties to hold the brushes in on my old brush box when I reused it the first time. Make sure the mounting plate is facing away from the commutator before pressing on the brush box. If there is resistance don’t force it on as you’re probably gouging the brushes and that’s not a good thing.






12. Put high temp grease on the starter cap bushing and press the cap onto the rotor shaft

13. Install the washer on the shaft then slide the c-clip back in place and put the small cap (full of grease) over the end of the rotor shaft and install the two philips screws as well. The two screws thread into the mounting plate of the brush box, so make sure the starter cap is clocked correctly in comparison to the brush box so that the conductor strap weather bushing fits into the dimple on the cap.





14. Slide the stator housing over the rotor and remember the magnet power, it will suck the housing on and may pinch your fingers if they’re not out of the way or you don’t have a good hold on things. Be sure the stator housing goes on the right direction with the notch end for the conductor bushing closest to the starter cap.




15. Clean the planetary assembly. I had a ton of grease in mine, some will be simply dirty because they haven’t been greased. Use brake cleaner or carb cleaner, towels & compressed air to get all the dirt, dust and grease off the assembly and gears.

16. Replace the planetary end bushing if necessary. The ID on my old one was very close to the ID on the new one I had ordered. It’s kinda difficult to get out, but with an easy-out or the right sized tap, thread the tap or easy-out into the bushing then use a pair of vice grips or such to grip the tool and then pry out the bushing. I wasn’t feeling that spunky, but I have pictures showing an easy-out in the bushing as a reference (no I did not damage the ID of the bushing). You could also use a dremel or machine out the bushing. After the old one is out, press the new one in.

17. Grease up the planetary gear set assembly and assemble the planetary gears and ring gear into the housing. There are brass bushings inside the planetary gears that are replaceable, but mine had minimal to no free play so I didn’t replace them. Clean up the housing cover as well and snap it into place.

18. Install the new solenoid plunger in the opposite manner the old one was removed. Place the solenoid spring into the solenoid plunger and then place the solenoid over both the spring and plunger and verify that the solenoid is clocked correctly. (There are 3 ways to locate it and only 1 is correct. Refer back to my initial assembly picture if you’re curious as to how to clock it and refer to the two studs and electrical connector orientation.) Hand start the three mounting screws then snug them down. Again I used an impact driver to avoid stripping the heads.






19. Grease up the sun gear & shaft on the rotor and slide the armature/rotor assembly onto the starter cast casing. Again verifying alignment then install the two long bolts and snug down them down.

20. Install the conductor strap onto the solenoid stud and snug down the nut.




21. Once I completed this I sprayed the starter with some black paint, let cure and reinstalled onto the car.

one bushing that's often overlooked and i don't see it on you list is the starter bendix shaft bushing, when it wears it causes the squalling sound after the engine starts ... sorry i don't have a part number but i do keep a few on hand... nice writeup by the way

jimbote said:

one bushing that's often overlooked and i don't see it on you list is the starter bendix shaft bushing, when it wears it causes the squalling sound after the engine starts ... sorry i don't have a part number but i do keep a few on hand... nice writeup by the way

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Thanks for the pointer. I was mostly concerned with the electrical end of the starter...so I've changed the thread title some

Great write-up. That's what we do. Help folks that need to understand stuff. If I had no clue about starters, your write up would be very valuable.

Wondering if any the site supporters sell a rebuild kit, much like a reseal kit for say the injection pump

Can I just say that I absolutely LOVE threads like this? Lots of descriptions, pictures, step-by-step guides, tools & parts list.

I usually order the brush kit from goldlion_autoelectrics http://www.ebay.in/itm/BOSCH-110-11...SHBOX-BRUSHES-PLUS-FREE-BUSHING-/161216358070 It appears he dosnt have any active sales for it right now, but he usually always does, he also sells solenoids.

Unless your solenoid is bad this is a good refresh bushing kit, combined with a good cleaning in general.

steve6 said:

I usually order the brush kit from goldlion_autoelectrics http://www.ebay.in/itm/BOSCH-110-11...SHBOX-BRUSHES-PLUS-FREE-BUSHING-/161216358070 It appears he dosnt have any active sales for it right now, but he usually always does, he also sells solenoids.
Unless your solenoid is bad this is a good refresh bushing kit, combined with a good cleaning in general.

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That was my source for both bushings and the brush box as well.
He was very helpful as well. An honest mistake, but he forgot to send one of the bushings the first time, so he shipped it immediately. The package showed up with a hole in it and no bushing, so he shipped another one. Good service in my opinion.

ihredneck said:

That was my source for both bushings and the brush box as well.
Was very helpful as well. He forgot to send one of the bushings the first time, so he shipped it immediately. The package showed up with a hole in it and no bushing, so he shipped another one. Good service in my opinion.

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Odd, I have never had an issue with his shipping, I have ordered 4 or 5 now (sold a few sets to guys locally) and I keep one on the shelf at all times. Cheap insurance for $20

Would the brush box from another 1.9L TDI of the same year be a likely interchange?

http://www.ebay.com/itm/BOSCH-START...531188?hash=item25ad9ce774:g:o6kAAOSwWnFV90Bc

It's still the same seller, but they don't say what series this starter is part of, nor does it have the bushing.

steve6 said:

Odd, I have never had an issue with his shipping, I have ordered 4 or 5 now (sold a few sets to guys locally) and I keep one on the shelf at all times. Cheap insurance for $20

Click to expand...

Yeah it was an honest mistake. No big deal.

hey_allen said:

Would the brush box from another 1.9L TDI of the same year be a likely interchange?

http://www.ebay.com/itm/BOSCH-START...531188?hash=item25ad9ce774:g:o6kAAOSwWnFV90Bc

It's still the same seller, but they don't say what series this starter is part of, nor does it have the bushing.

Click to expand...

Yes that one will work. Part # SBH0014 is the same as what I put on. Message the seller and ask to add the bushings and he will work it up for you.

Appreciate the info in this thread! I had the starter squeel, so today I tackled it!
Although I did not replace any of the parts, I took it all apart and cleaned and re-greased everything. I fought the brushes for half an hour before coming back into the house and pulling up the thread and found the zip tie trick....
Also, my planetary gears had some sort of needle bearings built in to the inner diameter, not brass bushings. I told myself to write down all the numbers on the housing when I had the starter out, but forgot! Pretty sure the starter is original with 160k miles. Probably 45-50% brush life left.
Would not have done this without the thread here!
Pete

Oh, and starter works perfect now, cranks faster, engine starts quicker. No squeel!

atownbrg said:

Appreciate the info in this thread! I had the starter squeel, so today I tackled it!
Although I did not replace any of the parts, I took it all apart and cleaned and re-greased everything. I fought the brushes for half an hour before coming back into the house and pulling up the thread and found the zip tie trick....
Also, my planetary gears had some sort of needle bearings built in to the inner diameter, not brass bushings. I told myself to write down all the numbers on the housing when I had the starter out, but forgot! Pretty sure the starter is original with 160k miles. Probably 45-50% brush life left.
Would not have done this without the thread here!
Pete

Click to expand...

Glad to hear this was able to help out! Sorry I don't have everything as far as pictures all taken care of yet. That will come soon though

Man, this is beautiful! Thanks you so much. Ordering parts tomorrow...hopefully find some in Western Canada.
Cheers
Joan

I'm in need of parts. Where can I find them?

dieselnuts said:

I'm in need of parts. Where can I find them?

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This guy goldlion_autoelectrics has everything I believe. Probably message him if need be if you can't find the parts on his page.

http://stores.ebay.com/goldlion-autoelectrics

If they don't have parts for your application listed, contact them, as they seem to let some of the listings expire and then reload them.

I bought a brush/brush holder set, bushing, and gear from them, but haven't pulled my starter to rebuild it yet.
They did ship in a timely manner though.