Bosch starter rebuild kits? DIY write-ups?

Yes as the title indicates, I'm asking for info and have nothing here to offer.

My starter on my car has been problem-free in the couple years I've owned it, but I know it's getting old. I also know most of the replacement Bosch starters on the market are remanufactured. Given the wide spread in prices for these remanned units, I have to assume they are not all created equal.

I want to buy an old starter from a junkyard or ebay and see if I can rebuild it. If I do it, I'll know what was done or not. I rebuilt my Bosch alternator not so long ago and it has been fine. I've looked all around the web, though, and can't seem to find an applicable DIY write-up for the starters, let alone anything about repair kits for the starters on our e39s.

I hope to be pulling mine out sometime in the near future and going thru it, clean, re-lube, and look at the condition of the communicator and brushes.
About once in every 10-20 starts it make a funny noise like starter motor is still running after the bendix pulls back or one of the bearings is starting to squeal.
It's 12 years old with 137K on it, I don't expect it to last forever. It's never been out.

My 97 does the same thing as you described Jim, but it has been doing this for the last 60K miles

I bought a used one for 50 bucks for spare. Wait a minute I have tested the damn thing

Good thread Pete. I could benefit any tips we get how to rebuild it.

I need to do more homework, actually was kind of hoping this isn't entirely uncharted territory for the forum. I've contacted a couple places that sell repair parts for automotive electrical stuff, still waiting to hear from them.

One ebay seller (triodiode) has a repair kit for six-cylinder e39 and e46 cars.

The ebay listing # is 350569995760.

I'll probably end up buying from him but I want to get a used starter to tear apart, first.

So what ever happened? Were you able to rebuild your starter or get the kit? Have the same problem.

Originally Posted by tracktitan800

So what ever happened? Were you able to rebuild your starter or get the kit? Have the same problem.

No, I haven't bought one to tear apart yet. This just got pushed down the long list of stuff to-do. I think the ebay seller still has that kit available, I just was assuming the starters should have bearings that wear out too.

Eventually I'll buy something to play with ... If you have a starter that's going out, it's probably best to buy from a reputable rebuilder or get one new.

I pulled my starter out a few weeks ago. I tried to get the solenoid off so I could take it apart however the torx bolts were starting to strip fo all I did was clean what I could get at and re-lube what I could get at. So far it hasn't made any weird noises like it use to.
I have pic on my other computer, I'll try to post them tomorrow.

Mine stopped working all of a sudden, first thing i thought a dead battery but after a quick jump, nothing! . A real pain to take out but when i did the brushes 2 of them where all worn out and 2 where like new. Replaced the worn brushes and some new lube and all is fine. its been a year now with no problem.

Not technically a rebuild, I just removed, cleaned, and lubed it to see if the noise it was making every 10-20 starts would go away. So far it has been fine.
The V8 starter takes about 30 minutes to remove from the bottom of the car.

Nice. For all to benefit, now, and long after we're gone, I'll add a cross reference here ...
- Where is the starter motor located (1) & an M52 starter motor DIY (1) (2) & removing the 540i starter motor in one hour (1) & the BMW TIS (1) and an E38 740iL starter motor DIY (1) (2) & how to remove the M52 starter motor without removing the intake manifold (1) (2) & what special tools are needed (1) (2) (3) (4) (5) & where is the starter motor relay (1) (2)

See also:
-BMW_E39_Starting_Systems_Starter_Motor_And_Solenoi d_Operation.pdf

JimLev, thanks for your post and pics. Somehow I neglected to follow this thread.

My starter has apparently decided it's time to act up. Twice in the past week, when I turned the key to the start position, the starter began to turn the flywheel but then stopped, as if it had seized or lost juice. Releasing the key and then turning it again worked each time, as if nothing had happened, with the starter cranking the engine over long enough for it to fire up. My engine always cranks in a split second so I haven't had any "opportunity" to hear the starter struggle.

I think I'll be buying a new starter this week and will try to rebuild the old one when I have the time.

I'm not sure if it's common knowledge, but applying a bit of force to the starter( as in hitting it with a wrench or something solid several times) will sometimes give the starter a bit more juice. This is quite helpful if you get stranded somewhere. Had this happen to me in my Maxima when I thought the starter was gone and I was able to get another 15k out of it.

I don't know anything so feel free to ignore, but, wouldn't we first try to isolate whether the problem were in the solenoid versus in the starter motor?

I don't know how to do that, but, when I was a kid, I watched folks short the two terminals on the solenoid with a large screwdriver as a quick test.

Would that work here?

NOTE: I ran an E39-only title-only search for starter, which found 77 threads, but NONE (but this one) seemed to cover rebuilding the starter motor. So, I guess, we're on our own when it comes to rebuilding the thing.

Googling, wasn't all that helpful either:
- 525i starter rebuild questions...
- LIfe expectancy of an E39 starter
- E39 starter repair kit
- BBA Reman BMW Starter Motor Problems and Faults

Originally Posted by Fir3n5m0ke

I'm not sure if it's common knowledge, but applying a bit of force to the starter( as in hitting it with a wrench or something solid several times) will sometimes give the starter a bit more juice. This is quite helpful if you get stranded somewhere. Had this happen to me in my Maxima when I thought the starter was gone and I was able to get another 15k out of it.

This is the "standard procedure" for a starter with a sticking solenoid and it is likely to work if that is the problem with the starter. It's sort of a "last resort" approach and certainly better than being stranded. If it works for you, you'll know that your starter has a sticky solenoid, which is easy to take care of, but you might as well plan on replacing the starter with a new one and repairing/rebuilding the old one as a spare. Note that new starters typically have a label on the motor warning against striking with a hammer etc.

In any event .... I ended up buying a brand-new Bosch starter through Amazon. $132, no core charges/returns, lifetime warranty, 2-year roadside service.

Here's the linky.

I disassembled the old starter only to find that the solenoid plunger/cylinder was quite sticky and the grease inside the planetary/reduction gear assembly had completely waxed and hardened. Brush graphite was on just about everything but probably wasn't a big problem yet. The brushes (four in the assembly) looked to be only about one-third worn from new, which makes sense as the motor only turns a couple secs each time you start the car. I cleaned everything out, lubed the planetary gears and bendix spindle as well as the surfaces of the solenoid plunger/cylinder very lightly. Re-assembled everything (fortunately just about every part only fits back together in one orientation....) and bench-tested like the guy does in this , and now I have a spare I can trust.

Only hitch I had with dis-assembly was that the three countersunk M5x0.8 bolts holding the solenoid unit to the starter base were heavily rusted on their torx heads. Two came out but the last one crumbled under my torx bit, requiring an extractor.

I will say this. It is probably far easier to remove/install the starter when the intake manifold is out of the way, but it can be done. I unbolted the two large torx bolts holding the starter base to the bell housinng by using extensions from under the car, unbolted the starter terminal lines from above with the airbox and intake boots etc out of the way, and was able to pull the starter out, again from under the car after much twisting and turning to get the bendix end to clear the bell housing.

Apropos of this thread, it might have been best to go ahead and buy the bushing and brush repair kit for the old one but I just put it all back together after seeing how much meat the original brushes still had.

When i took the starter out i found it was not Bosch but Magneti Marally, made in Italy ! After replacing the brushes it lasted 1 year before it died again, this time i got used Bosch unit which looked very new when i cleaned and lubed inside before instaling .