I got a knock in my 85 300D from when I plugged the breather and lost oil.
I'm trying to do the Piston connecting rod bearings without removing the engine. To do them I have to remove the huge lower oil pan.
The huge lower oil pan consists of the main large pan and a smaller pan underneath it. By removing the smaller pan and part of the oil pump, you can reach two of the piston bearings but to reach all five, you have to remove the main pan.
The #1 piston bearing was a mess. #2 was okay. The front main bearing was okay.
The larger oil pan--can it be removed? I am asking myself that question now. My biggest concern are the front rubber crank seal and the rear seal.
My question is WILL THE SEALS HAVE AN IMPACT on THIS JOB? Also there may be some interference with the front timing gear.
My theory is that even if you unbolt the lower pan, the engine crossmember will block you, so you will have to undo the mounts and raise the engine.
You may not be able to remove the main pan completely, but you may be able to tip it or rock it to get to the rear 3 pistons. The job will be messy because oil will drip all over your face. If the seals will cooperate I will do it. The engine is basically great, believe it or not.
I wont know for another few days..

The catalog list 52, 51.75, 51.5 mm rod bearings. Assuming crankshaft wear, would you select the smaller size (51.5 mm) bearings?

Save yourself a boatload of grief and pull the engine... You will need to replace the seals, the rear seal will require you to remove the crankshaft.

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Over 21 years I owned several:
w108
w110
w111
w115
w116
w123
w124
w126
w212

If you will tell us who gave you the idea this was possible or legit we will tar and feather them for you.....

plastiguage the bearings after you put them in...just to be certain clearances are in spec....it would ruin your day to find out they weren't after you put it back together and find out the hard way.

I vote on pulling the engins and doing the seals too....if they aren't leaking already they are likely to do so soon....

__________________
Proud owner of ....
1971 280SE W108
1979 300SD W116
1983 300D W123
1975 Ironhead Sportster chopper
1987 GMC 3/4 ton 4X4 Diesel
1989 Honda Civic (Heavily modified)
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Section 609 MVAC Certified
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"He who fights with monsters might take care lest he thereby become a monster. And if you gaze for long into an abyss, the abyss gazes also into you." - Friedrich Nietzsche

I still think its possible in all due respect.
Anyway I have nothing to lose. If I fail I pull the engine anyway.
I know someone who did it this way on a Lincoln.

The fact that you have to ask which size bearings is an indicator you are not an experienced engine rebuilder... which is different from removing and replacing parts on the rest of the car.....
The size bearings are not determined until you have taken the rods off the crank throw and put the plastigage on them and retorqued them... then you take it off and carefully inspect how much it was crushed comparing it to the ' guage' on the paper container the plasti-guage came in.
Then you order your proper size bearing.
That Lincoln was not a long stroke inline engine. And it was not a diesel.... where tolerances are much closer than most American made gas engines ever considered being...
But it won't hurt for you to try if you are well versed enough to tell when you have hit a procedure which you can not continue from underneath and do well... that is the point at which you change to normal rules...if you are to not lose your efforts from trying it this way...

Do yourself a favor man.!!
Pull it out!
You can do it ....We can help!!
Ask me how I know!

don't be tooo suuure....

I once drove a Lincoln with the sweetest little long-stroke inline diesel one could ask for... A BMW 6-cyl !

I think they only shipped a few of 'em....in....84-85 ?? something like that.

Ran like a swiss watch.

regardless, I agree completely, pull the motor.

I've had more than one case of a damaged bearing where the crank was still perfect. In fact, if anything, I'd say it's more common than having damage. At least in my own experience. Of course, I don't run them 30K miles after the knock starts...

In the heavy-equip diesels I work on, in-frame overhauls are far more common than pulling the engine out; and a crank will typically stay in spec for several sets of bearings (20K+ hours of hard time).

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WANT to BUY: 3.0L diesel engine.

My other diesel is a....

1962 Cat D9-19A, 2,000 cu-in TD
1961 Cat 966B, D333 TD, powershift
1985 Mack MS300P 8.8L TDI, intercooled, crane-truck
1991 F350 4x4 5spd 7.3 IDI NA
1988 Dodge D50 4x4 5spd 2.4 Mitsu TD
1961 Lister-Petter 14hp/6kw Marine Corp genset weekly charging 5400 lbs of forklift batt for the off-grid homestead.
1965 Perkins 4-108 Fire/water Pump
1960 Deutz 20hp/8kw genset

he seems to enjoy rebuilding engines so let him do it his way. check his website.

lots of engines to rebuild.....so little time, should be on his license braacket.

__________________
currently
[1981 300 td tdidi 165500 dark brown/palamino-Brownie-mine-3k miles of ownership
1983 240d 162+++ Anthricite grey w/ henna red interior and hella lights-wifes car-Red

the above two cars are for sale
and can be seen on the cars for sale thread here. pix also available.


240d-144+ Manilla Yellow w/ palmino interior-greasecar kit-Blondie-the college kids car

23" gt 21 speed still on original tires-still got the nubs
21" khs tandem

If bearing #1 is messed up you are well beyond the cheap fix stage. Find a replacement motor or sell the car and move on....

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Bill Reimels
Now down to one:
1972 300SE 3.5 W109 (Euro delivery)