I took my om617.951 to a local machine shop in preparation for a rebuild. They called asking about a "ball bearing" in the back of the block and whether or should be removed before they clean the block. I believe it is pressed in and is an oil galley passage or something of the sort. Anyone have any clue what should be done? Can the ball be removed? Reused? Are new ones available? Should I tell them to ignore it and just go ahead? Thanks in advance for the help!

Ya, the ball bearing is used to plug off the oil gallery while other makes of Engines use a threaded plug or a Core/Freeze type plug.

You will need to find one of those free online sites with the Manual. I am guessing the 617.952 Engine Manual would have the instructions. I believe it tells you how to remove the balls.

On other Engines if you don't remove the plugs during the hot tanking you need to remove the afterwards to make sure the Oil Galleries are cleaned out. Anything left in the Oil Galleries is not filtered.

If you can get a straight shot through it is normal on other Engines to run a brush through the oil gallery bore (similar to a Gun Bore Brush) as after coming out of the hot thank there is often rust and other crap in the Oil Gallery.

Note you did not mention the cleaning method so I am assuming old school.

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84 300D, 82 Volvo 244Gl Diesel

Link to official MB site

https://www.startekinfo.com/StarTek/outside/12265/disc_2/program/Engine/617/01-130.pdf

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Rebuild, meaning new cylinder liners, rings, and bearings? Care to relate what they quoted? One place in Southern CA which sells rebuilt OM617's charges ~$8K for a turbo one. Sounds like yours is non-turbo (.951) which have much more affordable pistons.

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1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans

IIRC I bought Mahle pistons for my .952, I hope they last as long as the originals did .

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-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

I wasn't aware that anyone was making pistons for the turbo 617 anymore.

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

Instagram: @maximed93

Just to be annoying, the .95x are turbo FWIW (.91x and .93x are not)

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1978 300D, 373,000km 617.912, 711.113 5 speed, 7.5mm superpump, HX30W turbo...many, many years in the making....
1977 280> 300D - 500,000km+ (to be sold...)
1984 240TD>300TD 121,000 miles, *gone*
1977 250 parts car
1988 Toyota Corona 2.0D *gone*
1975 FJ45>HJ45
1981 200>240D (to be sold...)
1999 Hyundai Lantra 1.6 *gone*
1980s Lansing Bagnall FOER 5.2 Forklift (the Mk2 engine hoist)
2001 Holden Rodeo 4JB1T 2WD

If you're pricing rebuilds, check out Reinvent The Wheel up in Oregon: Complete Diesel Mercedes Motors



They only work on old Mercedes, so they're pretty good at it.

This was a few years ago, the engine now has 40,000 miles since the rebuild .

FWIW, Reinvent The Wheel is *only* for very rich folks .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

Reinvent the wheel parts out perfectly running and driving cars in order to make more money on the parts. I personally would not support such a business

Some of us have parts stashes

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$60 OM617 Blank Exhaust Flanges
$110 OM606 Blank Exhaust Flanges
No merc at the moment

That's how I got my piston. Guy with a parts stash looking to clean out his garage.

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

Instagram: @maximed93