OM617 Front crankshaft seal nightmare - should I re-align the upper oil pan?
 

G'day folks,

I've just finished changing the front crankshaft seal on my 1981 W123 300D...

I followed the instructions on the DIY links on this site and all seemed to be well - the plastic cup special tool worked a treat.

However, as the upper oil pan is not perfectly aligned with the block it was very difficult getting the seal to fit. It went in - in the end - but the outside of the seal ripped. I've finished the job and so far there is no leak but I guess it won't last for ever!

So here is the question - is it a good idea to loosen the bolts on the upper oil pan and re-align it so there is no longer a misalignment of about 0.5mm (before fitting another front crankshaft seal)?

I guess I'm most likely to replace one leak with another - but you never know perhaps someone else has had this trouble and has done a fix before?

Here are some pictures that if you look carefully show the badly aligned joint.

Thanks in advance for any advice you may give.

Answer
 

Perfect surface alignment does not matter if it is fully seated to the engine block.
If it does not leak = all is good... :)





Have a great day.

Assuming the Upper Pan was never off it sould have been aligned from the Factory.

If you loosen the Pan there is no gasket just sealant on it so if you cannot re-seal it you could end up with a leak somewhere else.
Also, in theory ounce the Pan is loose you are supposed to align it with a Special Tool before you tighten it.

What does the tool do ? I'm getting ready to pull mine.

.

Thanks for the responses - if I find a link for that special tool for the upper oil pan I'll post it here.

Good lord. I have been looking in the Factory Service Manual CD and I do not see that tool.

So now I do not know if I just cannot find it or if I made mistake and there is no tool at all.
I am going to look in the printed book and chec.

OK I looked through the paper Engine manual and could also find no Oil Pan Centering tool.

So I am just going to beg for mercy and hope that my Apologia for being wrong is accepted.

Thanks for letting us know!

I'm waiting for something about the upper oil pan to come up in this epic:-

http://www.peachparts.com/shopforum/diesel-discussion/272444-konstans-1982-300d-engine-out-thread-post2418370.html?highlight=upper+oil#post2418370

Here's another one for the upper oil pan

http://www.peachparts.com/shopforum/diesel-discussion/261169-upper-oil-pan-gaskets.html?highlight=upper+oil+pan

Truthfully. I don't think there is any type of sealant or glue from the factory. Just a highly machined fit. But IMHO once you disturb it, you'll need to seal it.



I just aligned by sight.


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I would put a small amount of a good quality silicone on the seal before I would move the pan around. On the seal only , not on the pan/block surface, as I would not want any squeezing into the interior of the engine and coming off to clog something.

If I were you I would be concerned about the seal ring surface...it looks grooved to me.

Nice job cleaning the block and pan.

Hi Brad,

As everything is back together I'm going to wait until it fails - so far it seems OK as nothing is leaking.

I'm glad you appreciate the clean up job I used brake cleaner and lots of rags!

That's what I'd do!

Much better than "If it doesn't leak, take it apart to find out why".:D

Update:-

The front crankshaft seal lasted about 4 months - I've now removed the engine (to do some other stuff as well) to see if I can get it all nice and leak tight

It's always more fun to do things a couple times than to do them right once!

Although it is probably possible to get the alignment of the upper pan to the front cover without a special tool, in the interest of have more complete info on doing this task here is the alignment tool info:

617 589 00 14 00 Sleeve
Use/specification:

Engines 617.95
Sleeve for centering the front cover and oil pan to crankshaft.

http://www.startekinfo.de/etools/content/tool.jsp?toolno=617 589 00 14 00

I was not able to connect to the above link.

'Cause...(Wait for It)
 

It's a German/Deutschland Startekinfo Link.

(They've probably got ALL Kinds of neat helpful info we never are allowed to access)

I fixed the link in was incomplete, should work now to a picture of the tool and it being used, good luck!

I don't know about that! But here's a link to the tool info site that's available and where you can start a search regarding an MB factory designated tool:


http://www.startekinfo.de/etools/

That looks like a really expensive tool to do a nearly once in a lifetime job.
Might be better off finding a large socket that fits, or even just use the old seal. As has been suggested, lining it up by eye works pretty well too.

UPDATE:-

I've not seen this information on this forum before (disclaimer:- but that doesn't necessarily mean it isn't here) so I thought I'd add the thoughts of this engine builder I've pumping for information.

This is regarding the rear crankshaft seal NOT THE FRONT ONE but nevertheless may be of interest to some...

According to this guy if the REAR crankshaft seal is incorrectly fitted a lot of heat can get build up that can speed the failure of the main bearing closest to the REAR crankshaft seal.

For rebuilding my engine (that I'm now about to embark upon) I have been told to carry out the following procedure for fitting a rear crankshaft seal.

1) Before you start with the seal - fit the crankshaft and tighten the mounts (make 'em tight but don't go as far as torquing them) and make sure that the crankshaft spins freely. Remove crankshaft and remember how freely it span.

2) Once you are ready to fit the seal - lubricate and place a new seal in block and do the "usual" trick with a hammer handle to gently push the seal into position

3) Cut the ends slightly proud and then with a punch tap these ends flush

4) Now refit the crankshaft - torque as specified - and make sure that that it spins as freely as before.

5) Repeat the necessary steps above to make sure that the rear crankshaft seal on the upper oil pan isn't restrictive.

It seems like a good plan to me. Anyone got any comments?

So the plan is to fit things together without torquing to spec, observe and "remember" something, then install something that inparts friction, torque things to spec, then observe and compare to a "remembered" prior observation of something under different circumstances? And if not reconciled, repeating that procedure until you've convinced yourself things are correct!?

I suspect the heating bearing damage to be complete BS, and I'd follow the FSM rather than someone who came up with that. MB engineers are not perfect but you've got to give them some credit where credit is due and assume that they at bthe very least have considered the obvious when designing these systems and maintaining them.

Hmm you have a point with regards to the FSM that is always the safest way to go. However, sometimes you come across someone who obviously has a lot of experience and seems to be as honest as the day is long who - in albeit a long winded way - tells you to be extra careful about fitting a certain part... it kind of makes you think. Doesn't it?

Has anyone ever stumbled upon this sort of main bearing overheating problem before?