Rebuilding tdi starter how-to

[Mozambiquer]

Starters and alternators are things that baffle many mechanics, let alone the guy who just wants to drive his car and change his oil... I'm a starter and alternator rebuilder, and want to show that it's not some voodoo magic that only special guys can do. Anybody with a few tools and the correct parts can rebuild their own starter.
This starter is a Bosch starter from a mk4 jetta tdi. Other Bosch ones are similar. Vw also used Valeo, and some mitsubishi units.
Some of the principles apply, but they won't be the same.

IMG_20200926_172509.jpg

• Mozambiquer
• Oct 1, 2020

Before.

IMG_20200926_172604.jpg

• Mozambiquer
• Oct 1, 2020

First step is to remove the two screws in the middle of the back housing.

IMG_20200926_172650.jpg

• Mozambiquer
• Oct 1, 2020

Then Remove the cap and the "c" clip around the armature shaft

IMG_20200926_172724.jpg

• Mozambiquer
• Oct 1, 2020

Remove the two 7mm head through-bolts then Remove the back cap.

IMG_20200926_172806.jpg

• Mozambiquer
• Oct 1, 2020

You are now looking at the back of the armature and the brush holder.

IMG_20200926_172830.jpg

• Mozambiquer
• Oct 1, 2020

Remove the 13mm head nut from the solenoid, then work the brush holder out

IMG_20200926_172914.jpg

• Mozambiquer
• Oct 1, 2020

Next step is to pull the field and frame assembly off along with the armature.

IMG_20200926_172924.jpg

• Mozambiquer
• Oct 1, 2020

You are now looking at the planetary gear assembly. The cover for it may have come off with the field and frame assembly, if so, just pop it out of there. As a note, be careful not to set the fields over metal shavings... If you get shavings in there, it can be a big pain to get them back out and off of the magnets.

IMG_20200926_173047.jpg

• Mozambiquer
• Oct 1, 2020

Next, flip it over and use a t25 bit to remove the three solenoid mounting screws.
Remove the solenoid and then Remove the planetary gears. I replaced the drive, which is a HUGE pain. The drive is normally good still on these starters. You can tell though by turning the drive by hand while holding the planetary gears still. It should go smoothly one direction, and then not turn the other direction. If it doesn't, it should be replaced. Needless to say, I did replace the drive on this one, and during the struggle, I didn't take photos. I'll have to do another one and take photos of it.

IMG_20200926_174236.jpg

• Mozambiquer
• Oct 1, 2020

There are all the parts for the starter spread out on the table.
Now, time for cleaning and painting if desired. I have access to an aqueous parts cleaner which does an awesome job, but a can with mineral spirits and a paint brush could work too.

IMG_20200926_174613.jpg

• Mozambiquer
• Oct 1, 2020

Here's the parts I replaced. The drive, brush holder and solenoid. I used Brazilian made parts, which seem to be pretty good, but not quite as expensive as Bosch.

IMG_20200926_211722.jpg

• Mozambiquer
• Oct 1, 2020

Reassemble in reverse order and then you have a like new starter!

 

[oilhammer]

Couple mouse clicks and a shiny new one in a Bosch box arriving on my bench 20 minutes later is easier.

But in all seriousness, how is your cost effectiveness on this particular model Bosch starter? They sell theirs (genuine reman, which is sometimes NIB, depending on application and core stock condition) for around $155 wholesale. Not sure what retail is, probably over $225 or so. And of course shipping if you have to deal with that.

Oh, and VAG never used Mitsubishi starters on the ALH, I think you meant Hitachi. Those seem to be limited to, ironically, German-assembled late (wagons) only, though. I've never seen one on any of the Mexican or Brazilian cars. And the Valeos are even rarer, cannot remember the last time I saw one of those.

I used to rebuild a lot of older cars' (air-cooled mostly) starters and generators back when it was cost effective to do so. Just doesn't seem like it is any more.

 

[Mozambiquer]

Couple mouse clicks and a shiny new one in a Bosch box arriving on my bench 20 minutes later is easier.

But in all seriousness, how is your cost effectiveness on this particular model Bosch starter? They sell theirs (genuine reman, which is sometimes NIB, depending on application and core stock condition) for around $155 wholesale. Not sure what retail is, probably over $225 or so. And of course shipping if you have to deal with that.

Oh, and VAG never used Mitsubishi starters on the ALH, I think you meant Hitachi. Those seem to be limited to, ironically, German-assembled late (wagons) only, though. I've never seen one on any of the Mexican or Brazilian cars. And the Valeos are even rarer, cannot remember the last time I saw one of those.

I used to rebuild a lot of older cars' (air-cooled mostly) starters and generators back when it was cost effective to do so. Just doesn't seem like it is any more.

This one cost me around $60 for the parts. As I stated, I'm a rebuilder myself, I'm set up for it. Yes, I could get one for three times that price, but I like to fix things myself. I also know the quality that I build, which is why I offer lifetime warranty to my customers.
Thanks for the correction regarding mitsubishi starters vs hitachi. I get the two mixed up in my head and sometimes use them interchangeably.
I've seen a few Valeo units on vws. I just rebuilt the Valeo in my mk4 golf a couple of weeks ago.

 

[Johhny04]

Great writeup. Thanks for posting.

 

[STDOUBT]

Nice write-up!
Now pray tell - anyone have a link to a rebuild kit?
Or maybe just part numbers? For bushings too?
Just haven't found anything that's not in Europe.

 

[Mozambiquer]

Nice write-up!
Now pray tell - anyone have a link to a rebuild kit?
Or maybe just part numbers? For bushings too?
Just haven't found anything that's not in Europe.

I can get them. Send me a PM.

 

[KLXD]

Why would you have to rebuild a starter? Mine turns maybe a half second for each start.

I guess you guys up North have to run them a bit longer.

 

[oilhammer]

The failure mode for Bosch starters is they slowly lose their ability to spin at full RPM. They rarely ever just up and die like many others (Denso) do. One of mine is getting pretty slow.... but it is 21 years old and has nearly 220k miles. I will be changing it soon before it gets cold.

 

[Mozambiquer]

Why would you have to rebuild a starter? Mine turns maybe a half second for each start.

I guess you guys up North have to run them a bit longer.

As Oil hammer stated, the starter was getting slow. It still started the car, but with winter coming, it would probably have caused harder starting in the cold weather.
On my golf, I just rebuilt it because I was rebuilding the engine, and I like to do the starter and alternator at the same time, that way everything is good and ready to go. Generally, from what I've seen, the starters and alternators will last about 200-250k miles on these, unless they are really abused.

 

[noob_tl]

Where do you get the replacement drives? That's the part that always seems to fail for me, even on the genuine Bosch remans. After a while, they start slipping and can't get the engine farther than one compression stroke.

 

[Mozambiquer]

Where do you get the replacement drives? That's the part that always seems to fail for me, even on the genuine Bosch remans. After a while, they start slipping and can't get the engine farther than one compression stroke.

I get them from j&n electric. They sell exclusively to rebuilders.

 

[KLXD]

I was kinda poking fun. The starter is the least used thing on my car here in sunny So Cal.

Now the alternator is another story. At 350K the brushes were gone and the commutator had maybe .100" inch grooves. Bearings were fine though.

 

[Mozambiquer]

I was kinda poking fun. The starter is the least used thing on my car here in sunny So Cal.

Now the alternator is another story. At 350K the brushes were gone and the commutator had maybe .100" inch grooves. Bearings were fine though.

That's not bad lasting for 350k! I rebuilt the alternator on my golf which has 253k miles. It had a nice groove in the slip ring, but still worked well. I was taking photos of the rebuild for it in order to do the same type of write up, but my phone crashed and lost those photos.
View media item 136695

 

[JPR]

Thanks for the write up! My starter part numbers are:

Bosch 0 001 125 042 (043)
VW 02A 911 024 D

Before I saw this post I ordered this kit: https://www.aspwholesale.com/starter-rebuild-kits/bosch/pmgr/repair-kit-p14968.html

The kit includes:

1, 55-9103 ~ Shift Lever
1, 55-91400 ~ Support, Shift Lever
3, 62-2200 ~ Bushing, Planetary Gear
1, 62-91300 ~ Bushing, D.E., C.E.
1, 62-91305 ~ Bushing, Planetary Shaft
1, 62-91903 ~ Bushing, D.E.
1, 69-9115 ~ Brush Holder Assembly
1, 71-91103 ~ Gasket, C.E. Cover
1, 76-91817 ~ Stop Collar
1, 76-91818 ~ Retaining Ring, Stop Collar
1, 76-91819 ~ Stop Collar
1, 76-91820 ~ Retaining Ring, Drive
1, 76-91825 ~ Retainer, Planetary Shaft
2, 85-1209 ~ Phillips Screw, Bearing Retainer
3, 85-1334 ~ Phillips Screw, Solenoid Mounting
2, 85-1357 ~ Thru Bolt, Casing
1, 85-7501 ~ Washer, Felt

Can you please tell me if I am missing anything or am getting anything I don't need? Also I have not found where to buy the solenoid so I you can please post a source or PM me, I would be most appreciative. Thanks!

 

[JPR]

I forgot to ask which grease you recommend. These appear the best but are expensive:

Amazon.com: Polaris 2871460 Premium Starter Grease 2 oz QTY 1 : Automotive

Buy Polaris 2871460 Premium Starter Grease 2 oz QTY 1: Starters - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

G-MAN Low Temperature Grease PST-433 - Other Products - Amazon.com

G-MAN Low Temperature Grease PST-433 - Other Products - Amazon.com

www.amazon.com

My starter still works but has a loud whine. With 325K I think it would be prudent to replace or rebuild it but rather than roll the dice on a reman I want to rebuild the original starter.

 

[Mozambiquer]

I forgot to ask which grease you recommend. These appear the best but are expensive:

Amazon.com: Polaris 2871460 Premium Starter Grease 2 oz QTY 1 : Automotive

Buy Polaris 2871460 Premium Starter Grease 2 oz QTY 1: Starters - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

G-MAN Low Temperature Grease PST-433 - Other Products - Amazon.com

G-MAN Low Temperature Grease PST-433 - Other Products - Amazon.com

www.amazon.com

My starter still works but has a loud whine. With 325K I think it would be prudent to replace or rebuild it but rather than roll the dice on a reman I want to rebuild the original starter.

I sent you a PM about the solenoid, I generally use a multi purpose high temp grease for the lubrication. Though for some applications your need a specialty grease.

 

[krazykipa]

Thanks for the write up! My starter part numbers are:

Bosch 0 001 125 042 (043)
VW 02A 911 024 D

Before I saw this post I ordered this kit: https://www.aspwholesale.com/starter-rebuild-kits/bosch/pmgr/repair-kit-p14968.html

The kit includes:

[...]

Which of these part numbers, if any, is the starter bendix shaft bushing referenced by jimbote in this thread?

I have the classic whine/whirr/cat-screech sound on start, and would like to tackle it someday soon.
From what I've read, a clean and lube will only last a short while.
Is that mystery bushing the real culprit, and is it available separately anywhere?

 

[Mozambiquer]

Which of these part numbers, if any, is the starter bendix shaft bushing referenced by jimbote in this thread?

I have the classic whine/whirr/cat-screech sound on start, and would like to tackle it someday soon.
From what I've read, a clean and lube will only last a short while.
Is that mystery bushing the real culprit, and is it available separately anywhere?

That part is Bosch 1000390004 DE Bushing. It is available separately. I can get it to you for about $10 plus $10.50 shipping in the USA. That's oem Bosch. I can get an aftermarket one for about the same price.

 

[krazykipa]

Thank you for the quick reply, the pricing, and the part number! Gotta love being Canadian though...

In the interest of a local solution I did some poking around in the VW parts catalog.
The bushing is item number 4 in this diagram:

VW part number 02B911257G (originally -E suffix, superseded to -G)

Seems it is available from the dealer for around the same price!

Google shows images that look more or less the same as the ones that come up for the Bosch number:

VAG 02B911257G:

Bosch 1 000 390 004:

So, armed with this little bit of info, I think I'll place an order at the dealer and see what they can get me.

Will update with results, super grateful for @Mozambiquer, this thread, and this community! Fixing stuff is fun

 

[Mozambiquer]

Thank you for the quick reply, the pricing, and the part number! Gotta love being Canadian though...

In the interest of a local solution I did some poking around in the VW parts catalog.
The bushing is item number 4 in this diagram:

VW part number 02B911257G (originally -E suffix, superseded to -G)

Seems it is available from the dealer for around the same price!

Google shows images that look more or less the same as the ones that come up for the Bosch number:

VAG 02B911257G:

Bosch 1 000 390 004:

So, armed with this little bit of info, I think I'll place an order at the dealer and see what they can get me.

Will update with results, super grateful for @Mozambiquer, this thread, and this community! Fixing stuff is fun

That's great!

 

[ninedee_golf_tdi]

I know what I've been told, but what exactly causes the bendix to not retract causing the flywheel and bendix to grind after engine start ? And the fix for that is ?

 

[Mozambiquer]

I know what I've been told, but what exactly causes the bendix to not retract causing the flywheel and bendix to grind after engine start ? And the fix for that is ?

There are several things that can cause the drive to not retract, most commonly though is burrs on the flywheel or starter drive gear. There is also the fairly common noise that comes right after starting that can sound like a grinding sound after the engine starts, that's actually the drive vibrating in the bushing that is dry. That's the fix that the above mentioned bushing is for.

 

[krazykipa]

Success! Got the bushing swapped out and the bendix + planetary gears all lubed up, she gives out a bit more oomph, and the noise is gone now.

The bushing sits below a dust cover/seal, which must be removed for access, as you can see in the gallery below. I'm unsure what its part number is - it would have been a good idea to replace it, though I doubt it would have lasted a long time... I ended up using some RTV to hold the old one together, as the aluminum retainers were too loose and brittle.

IMG_3678.jpg

• krazykipa
• May 12, 2021

VW 02B911257G, Bosch 1 000 390 004-030

IMG_3681.jpg

• krazykipa
• May 12, 2021

Dust accumulation and visible gap in worn seal + bushing

IMG_3683.jpg

• krazykipa
• May 12, 2021

28.3mm inner diameter of worn bushing

IMG_3684.jpg

• krazykipa
• May 12, 2021

Bushing and seal layering close up

IMG_3685.jpg

• krazykipa
• May 12, 2021

Dust cover removed

IMG_3686.jpg

• krazykipa
• May 12, 2021

Remove bushing using socket from drive end, install from other direction

IMG_3687.jpg

• krazykipa
• May 12, 2021

New vs. old

IMG_3689.jpg

• krazykipa
• May 12, 2021

28mm inner diameter of newly installed bushing

IMG_3690.jpg

• krazykipa
• May 12, 2021

Used RTV black to help keep the (mostly useless) dust cover on.

 

[Nuje]

Great how-to, @Mozambiquer! Really appreciate such a detailed explanation of the steps involved.

Quick question: Is it possible to take the guts out of a 01M starter and put them into a 02J starter? Having done a few auto-to-manual swaps, I have a couple of perfectly good starters, but they're just the wrong "shape".

 

[csstevej]

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[Mozambiquer]

Great how-to, @Mozambiquer! Really appreciate such a detailed explanation of the steps involved.

Quick question: Is it possible to take the guts out of a 01M starter and put them into a 02J starter? Having done a few auto-to-manual swaps, I have a couple of perfectly good starters, but they're just the wrong "shape".

Thanks!
Yes, in one sense it is possible to do that, the back half of both starters is the same, the housing and drive are different from the automatic to manual, so you can swap the back half and solenoid are the same from one to the other, and I think, though I haven't tried it myself, you may be able to use the back from an automatic and the front from even a gasser manual, but I've not personally tried that. Maybe I'll get a couple and play with them.

 

[Nuje]

Sounds like I've found my next rainy-day project - thanks!

 

[codeweiler]

I can get them. Send me a PM.

Can I get sent this too please?!

 

[Mozambiquer]

Can I get sent this too please?!

I sent you a message

 

[Gluckmysock]

I sent you a pm