Hi all! I bought a 1975 W115 and during the drive home the car simply quit.
I haven't been able to troubleshoot it yet, suspected a leaking fuel line, because the starter also died. I replaced the starter with a new one, but it wont catch the flywheel. The flywheel has good teeth and the new starter works perfectly. Only thing I can see is that the new starter nose cone is clocked slightly different than the old starter nose cone.

Thoughts?

Sounds like they gave you the wrong starter.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Have confirmed it is correct starter. Just for some reason the nose cone is clocked slightly differently. Could this cause the starter to not engage the flywheel?

How did you confirm it? With Autobone? I suppose they already have your core, too. It sounds like you need a starter like the one that came off it, not what Autobone's computer says it takes. You might start with pelicanparts. Also, in this day and age, forget the chain stores. You're far better off taking your old one to a starter/alternator shop to get fixed. Takes longer, but at the end, you know what you have, not some Chinese piece of junk. With a lifetime warranty!
If you've already verified with someone reputable (we don't even know what engine you have) who knows what motor someone over the years has put in it.

1975 300D (W115) has an OM617.
It’s a Bosch reman starter from ACDelco. Ordered direct, not storefront, chill the hell out. I still have the starter that came off, I don’t turn in cores until I know without a doubt the new part works. It is 100% identical. Minus the slightly differently cocked nose cone. I mean maybe a degree or two. It’s the correct part number. The internals are identical. It bolts right up, fits perfectly, but when I turn the key the solenoid engages and it spins, but for some reason doesn’t engage the flywheel.

I’m asking here for help because maybe there’s something I’m missing before I go to Jimmys on Bumass Avenue and pay out the ass for an overhaul.

So, back to my question, if the nose cone is cast incorrectly, even a degree or two, will this block the starter from contacting th flywheel?

And if so, is it possible to gut the old starter and transplant the good hardware?

I'd expect the starter to interfere with the flywheel if the end of the starter were cast incorrectly. Pull the yoke back by hand on the new starter and see if it's flinging the pinion out. If the starter is a poor rebuild, it may not have the yoke engaged correctly so that the solenoid engages the motor but fails to fling the pinion out to engage the flywheel teeth.

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Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

pinion does fling out. i think im going to accept that this is an off cast and that the nose cone is what is causing the problem, return it and find out what an overhaul would cost