Replacing Front Crankshaft Seal with Special Tool - PeachParts Mercedes-Benz Forum

brianzero · #1 03-16-2007, 01:32 AM

Many of us have wondered why after installing the front crankshaft seal, it seems to fail quickly. I have created a tutorial on replacing the crankshaft seal using a cheap and effective special tool that overcomes seal seating issues. This tool is nothing more than a modified plastic cup that is used to guide the seal to a proper seating on the spacer ring. whunter is the one who uses this trick, and I thought that all of you in 617 land could use this tip.

Please excuse the crude nature of the renderings that Ive created to illustrate the steps...

Prepare the Patient
We will start the tutorial at the removal of the old seal. Clean the mating surfaces of all oil and debris with Carb & Choke cleaner. These areas must be completely free of oil before seating the seal. Failure to do this may accelerate the failure of the seal.

Step 1, Building the Special Tool
a) Find a plastic cup of 8oz (170g) plus or minus in size. I used a plastic yogurt cup.
b) Cut your cup. Cut off the top most half and bottom half. Cut vertically.
c) Break (smooth) all of your newly cut edges with 400 sandpaper. These edges, if not smoothed can cut your new seal.

Step 2, Using the Special Tool
a) With very clean hands, lube the ID (interior diameter) of the seal with ATF with a cotton swab. Think surgery.
b) Insert special tool in the ID of the seal. Aim flared side of tool towards the crankshaft.
c) Cover the spacer ring completely with the flare of the special tool.

Step 3, Seat the Crankshaft Seal
a) With the Special Tool completely covering the spacer ring, press the seal into the seated position. The seal will slide into position, and the inner lip of the seal should be perfectly seated because of the Special Tool. This is the purpose of the tool.

Step 4, Withdraw the Special Tool
a) Remove the special tool leaving the crankshaft seal behind. It should come away without any effort.

You are finished. No sealant needed, and the inner lip of the seal should have a proper seating on the spacer ring. This improper seating is often the cause of the rapid seal failure.

It should be noted that if the spacer ring is not damaged, it does need to be replaced.

Yes, imagine the crankshaft is inside the block...

Maki · #2 03-16-2007, 02:51 AM

Crude?? The drawings look like they could have come from a textbook.

Using the plastic cup to protect the inner seal surface is a neat trick. I used a similar procedure awhile back to replace the selector shaft seals on a BMW 540i transmission. My "shoehorn" for that installation was a short piece of a jumbo soda straw. Worked like a charm -- After I wrecked a seal trying to install it without a shim.

Nice job.

whunter · #3 03-16-2007, 03:17 AM

Quote:

Originally Posted by brianzero

Many of us have wondered why after installing the front crankshaft seal, it seems to fail quickly. I have created a tutorial on replacing the crankshaft seal using a cheap and effective special tool that overcomes seal seating issues. This tool is nothing more than a modified plastic cup that is used to guide the seal to a proper seating on the spacer ring. whunter is the one who uses this trick, and I thought that all of you in 617 land could use this tip.

in real life.

Thank you for the fantastic graphics.

rg2098 · #4 03-16-2007, 07:17 AM

How many times did we replace that seal Roy?

sailor15015 · #5 03-16-2007, 12:55 PM

Like heck they're crude. Nice diagrams and thanks for taking the time to make them up. I'm sure that'll come in handy some day.

mobetta · #6 03-16-2007, 01:12 PM

cool. I use part of a plastic lid that comes on aerosol cans when i did the wifes volvo seals, but next time around, i will try this one out. thanks for the exellent write up.

vstech · #7 03-16-2007, 01:49 PM

I am guessing by "crude" you are referring to Doc Brown's need for perfection, and his constant "Please excuse the crudeness of the models and lack of scale"
from the "Back to the Future" movies.
VERY nice tutorial!
Thank you VERY much!
John

dmorrison · #8 03-16-2007, 03:29 PM

Wonderful post.

Now do you have an idea on replacing the upper support bracket that makes the top half of the seal area??

The mechanic at the dealer recommended re-sealing this while I'm there as well as all the front seals since everything is out while doing the front crank seal.

Replacing the 300TD front crankshaft seal and other front of block oil leaks

Here's the problem. The manual calls for a special tool 617 589 00 14 00 to center and install the front crank housing cover. The tool has a centering hole for the crank and the outer size for centering the crank cove rand the upper oil pan. I was able to borrow the tool from the dealer ( neat trick

) so I was able to reseal the cover. I should of measured the tool for future reference. I'm sure I can measure it at the dealer if anyone needs the measurements.
Have you guys come up with any suitable designed tool for this??

As posted you can probably replace the cover by feel. your aligning the top cover edge with the upper oil pan edge while tightening to cover bolts. So I figured it could be done by feel of the edges by a careful person.

Dave

dmorrison · #9 03-16-2007, 03:41 PM

Quote:

Originally Posted by brianzero

a) With very clean hands, lube the ID (interior diameter) of the seal with ATF with a cotton swab. Think surgery.

I noticed that you specify ATF. The manual calls for grease in the seal prior to instalation. Job 03-324.

Why are you using ATF and not grease? An info would be helpful.

Dave

#10 03-16-2007, 04:05 PM

Thanks so much for the great tip. My '59 220SE is apart right now, for motor mounts, water pump, and the front seal.

Does anyone know where to get the rubber tits that go inside the harmonic balancer on these old timers. The local dealer had no idea, and just just gave me a dumb look today.

Thanks, John.

whunter · #11 03-16-2007, 07:04 PM

Quote:

Originally Posted by dmorrison

I noticed that you specify ATF. The manual calls for grease in the seal prior to installation. Job 03-324.

Why are you using ATF and not grease? An info would be helpful.

Dave

* It is a light lube oil.
* It is readily available.
* It will not gum up like cold grease.
* Seal technologies have changed for the better in twenty years.

whunter · #12 03-18-2007, 12:07 AM

Added to the DIY wikki tab.

OM617 ('82 300TD) Crankshaft Seal Replacement "Special Tool"
http://www.peachparts.com/Wikka/OM617CrankshaftSeal

Beagle · #13 05-28-2007, 06:10 AM

If the spacer ring IS damaged it does not need to be replaced as it can be turned round the other way and reused. The seal sits off centre on the spacer ring.

whunter · #14 12-02-2009, 11:06 AM

Quote:

Originally Posted by Beagle

If the spacer ring IS damaged it does not need to be replaced as it can be turned round the other way and reused. The seal sits off center on the spacer ring.

I disagree.
If you go to the trouble of replacing the front crankshaft/harmonic balancer seal, the seal ring/spacer ring should be replaced.
The part is currently ten dollars.
The seal ring/spacer ring should slip off the crank shaft, however I have encountered some that had to be split/destroyed to get them off.
If the sealing surface is less than perfect = you will be forced to go back in to do the job again = double the cost/time loss...

Spacer Ring OM615, OM616, OM617
6150310051 Harmonic/crank spacer ring/seal ring

Seal - front crank OM617
MB# 001 997 22 47

Cylindrical pin - harmonic balancer (two required, can not be re-used)
000007008244 Dowel for harmonic balancer, Large Engine Application List

Screw - pulley to harmonic balancer (six required on OM617 engines, can not be re-used)
OM617.952 + 616.912 as of engine# 027799 Harmonic pulley cap screws (six per engine)[/QUOTE]

OM615 and OM616
Seal - front crank
Screw - pulley to harmonic balancer
Call with your year, make, model and VIN# for correct part.

tangofox007 · #15 12-02-2009, 01:34 PM

Quote:

Originally Posted by whunter

I disagree.
If you go to the trouble of replacing the front crankshaft/harmonic balancer seal, the seal ring/spacer ring should be replaced.

Also, there is no assurance that the new seal is going to ride in the exact same location as the old one. And even if it does, it is possible that reversing the spacer won't adequately "relocate" the wear area. There is way to much work and risk in the job to leave an old $10 part behind and chance having to do it all over again in short order. .