Replacing front crankshaft oil seal

[rutger kohler]

I have the radiator and grille out of my 280SL.  I have noticed an small but annoying amount of sump oil around the front of the engine, higher than the sump pan itself.  I am thinking it might be coming out of the front crankshaft seal and wondered if you can change these with the motor in-situ and intact?  have looked at a post and answers from 2005 and it does look like you can, but i thought I would make sure before I strip off the front flywheel etc to get to it.

cheers

Rutger K

[Naj ✝︎]

Hi, Rutger,

Yes, you can.

I removed the damper first and had to get a puller to remove the counterweight.
Pushing on the new seal squarely can be a challange.

Naj

[twistedtree]

I think I read in the BBB that there are two different seals; one for use when the engine is apart, and the other for use as a re-fit like you are doing.  Does that ring a bell with others?  I also remember reading that there is a collar or ring that slides over the crank end and forms the running surface for the seal, and that this ring should be replaced at the same time.  And use sealant (sparingly) between the crank and ring so you don't get oil coming out between the two.

I think this was all JA17 advise.

[wwheeler]

I just replaced my front seal with the engine in. Not a problem but a lot of things to take off. Be sure to get a new crankshaft collar that the seal's ID contacts. The counterweight has threaded holes that I believe you can use with a puller to help. The hardest part is keeping the engine from turning when removing the crank bolt. With an automatic, I had to use a bar to stop it and again when installing the bolt at 150 ft.lbs.

The seal is a bit of a puzzle. I have seen one version where a flange goes all the way around, one flange that goes slightly less than 180* and one that has no flange at all. The one I bought from the Classic Center last year has no flange at all. However, it is made from a brown, high temperature, high performance material. It had the acronym FPM on the seal itself. I also have a NOS seal that has the half flange but I believe it is made from standard oil resistant Nitrile. I liked the flange idea but end the end, the better material trumped the flange. I also used a very thin ribbon of sealant around the OD of the seal just to be sure.

It has been in for a few months now and is dry as a bone.

[ja17]

Good advice Wallace,

My thoughts exactly. Yes do use some sealant on the inside of the metal sealing/spacer ring, so no oil can by-pass the seal by sneaking bbetrween the ring and the crankshaft.  Don't forget to pack inside the lips of of the new seal with grease, before installation.

[rutger kohler]

Thanks guys

Rutger Kohler

[rutger kohler]

Hi, actually replacing the seal and ring that it runs on now.  Have got the seal out but the ring appears to be difficult to hold onto, to pull it out. Any ideas on this plse?

[280SE Guy]

This is what the Mercedes tool to get the ring out looks like. Maybe this will give you some ideas.







Hope this helps.

Regards,

280SE Guy

[wwheeler]

There is a picture on this site that shows a homemade tool. It is thin wall PVC tubing that has (6) slits evenly spaced at the end. The slits are probably 1" long and allow the tubing to expand over the sleeve. Then you install a hose clamp towards that end which squeezes and holds the PVC tubing onto the sleeve. Hopefully, just a quick pull will take it out. If it is really stuck, you may have to get the heavy duty version that Bob is showing.

[rutger kohler]

Crikey!! the official tool looks like it could pull a propeller off the Bismarck! I like the PVC hoseclip idea but will probly use steel exhaust  tube instead of pvc, someone might have superglued in on though...

[wwheeler]

I found the thread for the homemade tool. http://www.sl113.org/forums/index.php?topic=7282.0 Not exactly as I described, but you get the idea. That MB tool looks as if it could pull the sleeve off even if it was welded to the crankshaft.

[Benz Dr.]

This small ring does wear but not very quickly - the seal will wear a lot faster. A small shiny area on the ring is from where the seal was running and as long as there is no groove worn, you can probably leave it in place.
Rather than having the seal wear against the crank shaft, the factory made this ring so it could be replaced as needed. I think it's much harder than the crank shaft to provide for long service life. Dirty oil is the main reason for front seal wear.

[rutger kohler]

Hi there, I have got the old sleeve out, and the seal; and replaced both with new ones.  The oil seal doesn't go back as far as i would like on the sleeve, in fact it only just clears the chamfer on the front.  The oil seal is flush with the front of the engineblock and sump, and i don't want to drive it in any further as I think I read a thread where the crankshat gears behins it start to chew it?

[Naj ✝︎]

Hi, Rutger,

Could you tell us how you pulled the sleeve out?

Naj

[450sl]

drill a 3-4mm hole in the sleeve en then split it open with a chisel

[rutger kohler]

I decided to make an upmarket model of the pvc idea.  Set a 11/2"  screwed pipe socket up in the lathe and bored about 1.25" deep to about half a thou" oversize  on the sleeve OD.  The idea was to screw a 11/2" (thats one and a half inch) screwed plug into the other end, which was still screwed.  I was then going to drill and tap say 1/2" unc through the centre of the plug and provide a a bolt to go into that end.  This would provide the pulling power, and if the plug moved in the socket thread i could lock it with another shifter.

On the bored end of the socket I was going to cut six slots and then get an exhaust tube U clamp that would fit over it, to tighten up, rather than a hose clamp.

However, after boring the socket out, I tried it on the old sleeve, and much to my amazement it picked up on the sleeve and starting turning it!!  I got it out without building the rest of the tool.  Doesnt say much for the finish in the bored hole!

If you are interested in this you might be interested in the basic puller I made to get the damper off.

Still be interested in comments on the seal position on the new sleeve, can post a pic if useful

[wwheeler]

It has been a few months since I installed my seal , but I remember the details. Being a seal designer, I notice some things that others may not.

Which seal did you use? There is the new MB seal that is brown (hi temp material) with no flange and a black seal with a half flange. The black seal is taller by the width of the flange. The flange seal sticks out of the block by the width of the flange and the brown seal is installed flush with the block.  Both seals have a main sealing lip (with garter spring) and a smaller excluder lip. The excluder keeps crud out. The main lip faces the crank (oil) while the smaller excluder faces out toward the counterweight.

The main lip should not be near the edge of the sleeve, but much further back. But the excluder IS positioned right on the chanfered edge of the sleeve when the sleeve is pushed all the way in. Note that the backside of the counterweight has a protrusion that "extends" the length of the sleeve by about 1/8". The taller seal fits deeper into the protrusion and the brown seal fits right at the junction of the sleeve and the counterweight protrusion. Not a big difference either way.

The one strange thing is that the excluder diameter is .015" LARGER the sleeve or protrusion. In my opinion, it should be slightly smaller so that there is contact. Incidentally, both seals had the same excluder diameter. So in this case, the excluder is acting more like a shield and not like a proper wiper. So when you pack the grease in the seal, the grease is what is keeping the tiny particles of dust and so forth away from the main sealing lip.

[rutger kohler]

Hi Wallace, thanks for that, I guess i didn't notice the main seal lip further in, makes me feel a whole lot better (I know I got the seal in the right way round). The seal I used is from SLS Hamburg and is black. Doesn't have the locating lip or collar like the other one you mention.  Is it worth me posting a photo of the home made puller I made to get the balance flange/boss off? The puller could be made by anyone with a 4" vice and a 10mm clearance drill in a pwer drill?

[ja17]

Hello,

As I often said the Mercedes Factory Shop Manuals are like a TV Soap Opera. You need to know what happened in the previous episodes along with the current episode to understand exactly what is going on. In addition episodes in the future will also contribute to the pool of information.

With this in mind, I found some relevant information in post-Big Blue Book factory literature.

"The engines feature oil pans with and without machined faces around the radial seal mounting hole. Oil pans with plain faces always require radial seals with half shoulder, whereas oil pans with machined faces accept both half and full shoulders. Combined radial seals are available for repair purposes. They consist of two different materials and have a sectional outer ring. Inside Silicone (white), outside Polyacrylic (black).  These combined radial seals (black outside, white inside) must only be used in conjunction with hard chrome-plated spacer ring #615 031 01 51.  In contrast, the combined radial seals which are black outside and green inside may also be used with spacing rings not having chrome plating. Materials: Inside: Viton (green), Outside; Acrylic (black) " *

*information taken from Mercedes Factory Literature Job #03-324 "Replacement of front crankshaft radial seal on crankshaft"

A photo in this procedure shows a smoothly machined surface on the vertical front of the oil pan. This machined surface on the oil pan accepts both the shouldered and un-shouldered oil seals.

For what its worth,  there is nothing to say that Mercedes has not changed materials in the front seal or the spacer ring since this publication. So the information above may not be current.  

[wwheeler]

Joe,

You are certainly right about needing to know what happened prior to understand the current! When I talked with the Classic Center about this seal, they said that this seal has changed part numbers more times than just about any part. That being said, there are probably many configurations out there. I have seen a seal with the full shoulder as mentioned, but not often. So I guess the seal with a shoulder can only be used on the portion that is machined? If the pan is machined, then it can accept the a full shoulder. So what is the purpose of the shoulder?

That is interesting about the seal materials versus spacer ring material. Silicone (white) is high temperature and chemically resistant and very resiliant, but is not so abrasion resistant which to me wouldn't as long. Viton (green) is a good hi temp, chemically resistant compound that has good abrasion. The new brown seal I installed had "FPM" molded into the part. FPM or FKM is a generic name for a floroelastomer. Viton is the registered trademark of DuPont for its floroelastomer. Too much information!

Please post the picture of the tool. It is always interesting to see a new twist on an old idea.     

[rutger kohler]

Hi, I tried to post a picture of the puller, however our digital camera is set to high resolution -too big to go on the post and i didn't know how  to change.  Have a bit more time now so will try again.

Picture attached that shows the bored out pipe socket I used to remover the seal sleeve, and the puller for removing the damper boss or collar.

The puller has a piece of 5/8" unc screwed rod with a nut under the plate, and two locked nuts together to be turned with a spanner.  I put the large crankshaft bolt back in, without the washers, and did it up hand tight. The 5/8" screwed rod is tightened up against the crankshaft bolt head.

The plate is made out of 1/4' scrap mild steel plate and 6 clearance holes (on the cap screws) are drilled on a 2.5" PCD.

Care has to be taken to make sure that two flats on the crankshaft bolt head are aligned with the two round keepers that hold the boss  from turning on the haft, as the corners of the bolt head interfere with them.

I used the 6 cap screws  to hold the plate, I actually found it was easier to screw the cap screws into the boss about 1/4" then screw the 5/8" screwed rod up tight on the crankshaft bolt head then slowly do the cap screws up evenly.  The thread on the cap screws is about 7/8" long so you have about 5/8" of movement before slacking them back to 1/4' deep again and tightening up the screwed rod. (Make sure the cap screws are threaded into the boss at least 1/4" otherwise they will strip!!

A smack on the end of the 5/8" locked nuts helps to get things moving.

After I finished, I realised you don't need the 5/8" screwed rod, could just use a handful of say 3/4" washers packed between the plate and the crankshaft bolt.  This might make it easier for someone who cannot drill 5/" holes in their home workshop.

[Paul Robinson]

My front seal (130.982) needs replacing, so I am thankful for the above comments.  This will get me started.  Just a couple of questions though.

1.  There appears to be a consensus to put sealant between the the spacer ring and the new seal.  What kind of sealant?  Would  Indian Head gasket sealer (that I used on my rear axle seals) suffice?  If not, what would you all recommend?

2.  No mention is made of removing the oil pan in order to replace the spacer ring collar and seal.  So I am assuming that the pan stays in place?

Thanks for your time,  Paul

[Paul Robinson]

And one more question.......

3.  Were the oil pan to be removed (for whatever reason), is a sealant used during reassembly since there is no gasket between the block and the pan?  If sealant is necessary, what kind?
Permatex Form-a-Gasket 2B? Indian Head gasket Sealer?  Thanks for your time, Paul

[ja17]

Hello Paul,

Use the Indian Head between  the inside of the spacer ring and the crankshaft. You can also use a little between the outer diameter of the new seal and the opening in the block. The inside lip of the seal, which contacts the spacer ring, should be packed with grease. Permatex #2 is a good choice for the oil pan to block surface in case you need to take the pan off, but you do not need to take the pan off. Take a blade and "break" the sharp 90 degree edge off the seal opening in the block and oil pan before pressing in the new seal, this will help prevent the sharp corner from cutting up the new seal as it is installed. Lastly take a good light and make sure the inside lip of the new seal is seated on the spacer ring and not in front of it. Re-install the counter balance paying attention not to install it 180 degrees out!

[Paul Robinson]

Joe thank you!  The 280 engine is out of the car and on a test stand, so everything is accessible.  I ran the engine today and got compression readings on cylinders 1-6 of (155/156, 158/159, 159/159, 160/160, 159/160, 165/164).  Not sure what compression is normal for a factory new, or rebuilt engine, but I'm happy with this.  It was advertised has having "only 77000" miles on it, so maybe I did O.K.  Next step is to address the seal issue, and replace a leaky water pump.  I was asking about sealing the oil pan because I do have access to the rear rope seal (at least the lower half) if I were to remove the pan.  However since it is not leaking I'm thinking to just to leave well enough alone since I probably don't have a surgeon's eye or hand for cutting/trimming and installing one.

One last question.  How much does the external oil cooler contribute to keeping the engine within proper temperature range?  This 280S engine is going into a 1964 220SEb coupe, which did not have an oil cooler, so I need to find a suitable location since the radiator cavity on the 220 is too small for the side-by-side oil cooler/radiator arrangement.  
I've read that because of larger bore size, the 280 engine has fewer water channels circulating through the block/head for cooling.  Is this why the external oil cooler was added?
I'm tempted to test the engine on the stand with the oil cooler out of the loop, just to see how it affects the operating temperature (steady 175 degrees now).  

If I can not find a suitable safe location in or under the engine bay for the stock oil cooler, then the next choice would be an aftermarket one with a different geometry, or perhaps even a smaller one off of an old 300D.  

This project of mine I realize is not for the purist.  The 280S engine has dual Webers.  I replaced the rear 4.09 with a 3.27.  I'm using the manual transmission from the 220SE to replace the automatic that was mated to the 280S ( 220 flywheel changed out to a balanced one).  This car is a Frankenstein for sure.  The oil cooler is the last piece of the puzzle.  If it's a necessity then I'll have to make space somewhere.

Thanks for your time and response.

Paul