I've heard good things about Mean Green starters as well. They make gear reduction starters, spin faster with less draw. They are kind of pricey and made to order, so it takes a while (I've seen up to a few month wait time), but they do make a starter for the OM616/617.

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Milan Brown 1979 240D, rebuilt OM617.952 turbo diesel, rebuilt 722.315 transmission (my only daily driver)

Instagram: @maximed93

I read the reviews on the Mean Green starters. They seem to be very powerful. But, there were alot of complaints that they quit working after a year or two. No thanks. I just ordered a rebuilt Bosch from Peach.

Does anyone know the socket size to remove the block heater? (1984 300cd) I tried a 1 3/4 inch and it was too big. 48MM?

Sometimes 3/8 extensions torque twist. That top starter bolt can be just too tight for them. Try to use 1/2 inch. I found the really tight ones snap loose initially rather than just back off under pressure. A piece of pipe over a strong bar is not unusual to get it to snap.

I would not chance using a worn or cheap bit on the starter bolt.

The rear differential plug falls into the same category but easier to get to. The first one I was uncertain if the plug would start or a piece break out with the plug. I was using a five foot bar.

Just replaced the starter motor on my RHD 300TD nonturbo. A few points: use about 650 mm of 1/2" extensions, including a couple of wobble joints on a good quality Allen key socket 3/8" bars are too light. I use a bit of water pipe to extend the handle as a breaker bar. Tapping with a hammer helps.
You will knock the vacuum line off the auto trans modulator. Its easier to clean it up first rather than later.
Remove the starter motor from above. Take off the air cleaner for better access. If your motor mounts are a bit soft, clearance for extraction of the starter motor from above past the exhaust over the steering box (RHD) will not be adequate and you will need to jack up the engine a few mm (its very tight). The auto trans filler line can be detached where it is bolted next to the rocker cover. I also loosened the connecting banjo bolt at the lower end to facilitate rotating it out of the way (just a little - you don't want to lose ATF). There is one tranverse flex pipe (air con?) under the air cleaner which should be unbolted (two 10 mm bolts) and a couple of cable ties which can be removed to give a bit more wriggle room.
I tried to remove the starter motor from below and there was no way without dismantling steering linkages.
This is the third starter motor I have replaced in a w123. The first was with a Bosch remanufactured unit which failed after about 100 km. the next two were AC/Delco which have been satisfactory. My location in Australia means that it is not practical to return a faulty unit.
Andrew

It is a tight fit to get to the bolts. I have done 3 so far and don't remember it being too awful and one car lived in salt country. The 240D starter is a 15 min job with gobs of access. That xtra cylinder.............

I did the crazy extension thing fixing the starter on my w123 wagon.
That top bolt sucks the most because it's hard to see.
When my starter solenoid got sticky, years later, I had to do it again. I made a little tool that could eek in from the side. Maybe on other models this isn't possible, but...

Got a 10mm allen wrench and cut a short piece off, and manage to get it in there and turn it with a 10mm box wrench and a cheater. A 10mm ratcheting wrench is nice once you get it moving.

Now if I had not already removed, cleaned, and anti-siezed that starter bolt years before, it probably would not have worked. I recall it took a LOT of force to break that bolt loose the first time.
Wasn't too difficult to get enough torque tightening it back using the little wrench with a small cheater.
I think it's 37 ft/lbs for those bolts, so it's pretty tight but nothing crazy. Those bolts seem impossible at first probably because they are decades old and corroded, or some shop just impacted them on and didn't care what the actual torque was.

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1985 300TD 1981 Scirocco 1.6D conv 1986 Golf 1.6D 2003 Golf TDI

I also have been known to heat up things using a torch. That said, Kroil Penetrating oil is the absolute best at breaking things up. I used to use PB blaster, WD-40 and all the rest. They can't hold a candle to Kroil Pentrating Oil. use a syringe to draw it out of the can then inject the oil around the stuck/frozen bolt. Do it again in a few hours. Presto, like magic, out comes the bolt!


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^^^^^ +1000% Kroil is, by far, the best I've ever used. Not cheap, but you get what you pay for. Wire brush away any rust and corrosion before application. Put it where it needs to be, and WAIT. Then re-apply and wait a little more. Your patience will be rewarded. Kroil hasn't let me down. Great product. PB what?

For sure, once I got turned onto Kroil, I never looked back. WD-40 and PB Blaster sit on my shelf looking very lonely.......

Why not go ahead and take your Starter apart to see what might be the issue.
The only issue I had doing that was the Phillips head screws stripped the heads (I replace them with Allen head screws).

I found that my Brushes were worn down to about 1/4 inch thick.

I was having the same clicking symptoms a bad solenoid would cause. However, one of our member suggested that the same symptom was caused by the Brushes.
I had ordered a new Bosch Solenoid but decided not to use it. After replacing the Brushes and the passing of several years the old solenoid has been working fine.

At the time I did it there was Bosch and Monark brushes being sold on eBay. Monark sells a kit with brushes and all of the bushings for the Starter (I bought this though I already had bought and used the Bosch brushes).
If you decide to replace the Brushes the originals on mine were like welded to the Brush Plate. Not hard to cut off. The Brush Plate comes with holes in it for the replacement Brushes but you have to be sure to get brushes with the metal plates with holes on the ends.

This is not my thread but I posted some details in it like pics of the brushes and the Monark kit.
Anyone have good source for starter rebuild parts

There is 2 tests you can do with your ohm meter on the commutator area and you need to decide if the brush contact/commutator area area can be sanded down.

There is another test for the armature which only a re builder would likely have with something called a "Growler" which tests the winding's. However, since 1968 on the vehicles I have owned I have never had a bad armature due to issues beyond the commutator area being worn.

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84 300D, 82 Volvo 244Gl Diesel