1970 Front Crankshaft Seal Replacement - PeachParts Mercedes-Benz Forum

mercifiknow · #1 12-29-2014, 10:45 AM

Hi Guys,

I bought my first Mercedes and I'm attempting to restore her but i've got to keep her running first. And that's why i'm here:

I'm trying to replace my front crankshaft seal on my 1970 250C (M130 Engine) and had a question or two on tools. I apparently need to remove the fan hub. I will need either a 36mm or the 32mm wrench according to most websites. Anyone know which size? I know Pelican offers these.

The second question I have is do I need to buy the hemispherical water pump retaining wrench as well? If so where can I get this (or have a part number for it)? The reason I ask is that I've searched for this for a while now and haven't found it (or the p/n). Samstag sales asked if I had a p/n they could order it. Not sure if Pelican can order it, but when i asked about this I got nowhere.

Thanks!

Carpenterman · #2 12-29-2014, 05:40 PM

Are you talking about the harmonic balancer? You should remove the pulleys (8mm allen I think) and then the balancer (27mm). Order new dowel pins while you are at it and make sure the new dowels are the same length as the originals. You'll need a puller and something to jam the balancer against the motor.

I have no idea what you mean by the water pump wrench. You shouldn't have to mess with the water pump if you are replacing the front crank seal.

Frank Reiner · #3 12-29-2014, 06:20 PM

Quote:

Originally Posted by mercifiknow

Hi Guys,

I bought my first Mercedes and I'm attempting to restore her but i've got to keep her running first. And that's why i'm here:

I'm trying to replace my front crankshaft seal on my 1970 250C (M130 Engine) and had a question or two on tools. I apparently need to remove the fan hub. I will need either a 36mm or the 32mm wrench according to most websites. Anyone know which size? I know Pelican offers these.

The second question I have is do I need to buy the hemispherical water pump retaining wrench as well? If so where can I get this (or have a part number for it)? The reason I ask is that I've searched for this for a while now and haven't found it (or the p/n). Samstag sales asked if I had a p/n they could order it. Not sure if Pelican can order it, but when i asked about this I got nowhere.

Thanks!

m:

Removing the fan from the water pump is required (10mm), after removing the radiator and fan shroud. Then, as C-man has indicated, the pulleys from the water pump and crank hub, the harmonic balancer, and finally the hub from the crank. The crankshaft will have to locked to prevent rotation when loosening the center bolt (300-400 ft-lb!); a large screwdriver can often be wedged between bell housing and ring gear.

No dowels in gasser crank hubs; those are found in oil burners.

Carpenterman · #4 12-29-2014, 08:40 PM

Sorry if I was wrong about the dowels. I have not had the hub off of my m130 yet, but there were dowels on my gasser m180. And of course the om617.

cth350 · #5 12-30-2014, 09:01 AM

To do what you've described (replace the seal) basically do this:

- Pull radiator
- Disconnect the fan from the water pump
- Loosen alternator & power steering belt
- Remove pulley from the crank
- Remove the bolt from the crank
- Remove the harmonic balancer from the crank
- Remove the front seal
- Assembly is the reverse of removal

The radiator is held down with a rubber donut on each end that can be stretched with a well placed screw driver. At the bottom are two fittings for the transmission cooler. A 19mm flare wrench is the right tool to remove them. Keep them clean and free of dirt. Catch the fluid that will spill lest you make a puddle of red goo. Be sure to replace the lines if they appear worn. Loosing one of these is unpleasant.

The alternator adjuster comes in two styles. A simple L shaped metal bracket and a more interesting long bolt that looks like a nut over the end. Either way, loosen, but don't remove the bolt facing the radiator (13mm wrench would do it). Then you can change the adjustment nut if it's the long bolt style. That requires a deep 14mm socket, IIRC.

The power steering adjustment is about as complicated, maybe a bit more so.

The pulley is attached by 6 in-hex machine screws (cap screws). You need a long 6mm allen wrench to remove it and you must ensure that you remove the dirt from inside each one. Sears or harbor freight can sell you the right tool. You're going to need the 5mm, 8mm & 10mm long wrenches too some day soon, so buy the set.

The crank bolt is 28mm. A 1 1/8" socket works too if you already have it. It is torqued down very well. You can't casually remove it. You need to immobilize the ring gear on the flywheel to do this. The easy way is to remove the inspection cover at the back of the engine that exposes the flywheel. You could also remove the starter, but that's more complicated (and you must disconnect the battery first or you'll likely destroy the car).

With the inspection cover off, you can jam a screw driver in there and let it get wedged in place as you loosen the nut. If you like buying tools, they make something that meshes with the gear teeth; that works too. When I started doing this way back when, I took a small piece of aluminum plate and cut it to look like a crescent moon with teeth cut-outs (lots of time with a dremel; it's lovely in its crudeness). The result is a nifty tool that I've used for about 30 years now, when I remember where I put it. When I can't find it, I use a screw driver. To get the screw driver back out, remember to turn the nut the other way after you've gotten it loose. Another easy way to do this job is with an impact wrench, but I'm hopelessly stone age.

When you take the nut off, there are a set of like 3 cone washers. put them back on pointing the same way. and you're going to want to use a torque wrench on the bolt. Don't just (over) tighten it with all your might.

The harmonic balancer removal tool from sears or harbor freight works just fine. It's a simple gear puller of sorts. Don't damage the threads for the crank bolt.

Now you can clean the front of the block and replace the seal.

Having said all that, this usually isn't the first job somebody does on one of these cars unless that seal's really, really bad. That or you've already been having fun with the car and you haven't shared your adventures yet.

The M130 is a pretty simple motor and presents some challenges due to its age and the precision engineering involved. Welcome to the forum and we look forward to helping by being your arm-chair mechanics.

-CTH
PS. While you have all that apart, you might want to remove the water pump housing and replace the little rubber hose that connects it to the thermostat. You might also want to do a coolant flush either before or after all of the above.

Carpenterman · #6 12-30-2014, 10:17 AM

Does any one know for sure if the m130 uses dowels to key the hub to the crank? My manual shows that it does.

mercifiknow · #7 12-30-2014, 11:48 AM

Holy Smokes on a Stick! Never expected such awesome responses!

C-man: here is the hemispherical wrench I was referring to: http://www.samstagsales.com/images/klann0366-7.jpg

My understanding (and I'll be the first to admit this is my first time doing this type of work so please bear with me) is that the visco fan hub had to be removed. To do this required two wrenches which i described.

I do believe you have to remove radiator and the shroud like cth350 states. There then loosed up the belts. You are required to remove the pulley that sits in front of the crankshaft.

Having said all of this everyone's comments are EXTREMELY helpful!

cth350: I bought this and it came like this. I surmised that I had an oil leak given that I had about an 1/2" of oil everywhere underneath the engine compartment. Probably should have passed on this but there really aren't that many left from what I've gathered (didn't buy for investment but to tinker with and restore for pleasure). I called an Indie and claimed for a $110 he would find the leak and clean the block. It took 4 hrs to clean the block well enough to find the leak. Got my money worth on that! Anyway, turns out I had 2 leaks front crank seal and timing chain O-ring seal (will have to ask about that on later when I'm finished with the seal but before I put everything back in). He said he would do the job for a little over $1000. Mercedes dealership said under $600. After seeing your write up I may have to send it to the Dealership

. Haynes didn't make it out to be this nasty! I will attempt this after I figure out why my window quit working (right in the middle of this).

I bought a Mercedes Body & Chassis Service Manual but haven't splurged on the Engine manual. I also have a Haynes (not the most helpful book judging by your write up; yours is WAAAAYYYY better). Is the manual worth it?

Is there a photo somewhere that shows my engine (and compartment) with all the descriptions of parts? They removed the Zenith carbs and put on Webers (more stable for running) but the engine compartment is foreign :roll eyes: to me on somethings.

Really glad to be on this forum! Can't say thanks enough!!

Frank Reiner · #8 12-30-2014, 12:25 PM

C-man:

I stand corrected on the matter of the dowels. I just took the balancer off a M110, and lo and behold, dowels! I have not worked on that area for 25 years. I was thinking in terms of the V-8 crank hubs, which use a Woodruff key.

mercifiknow · #9 12-31-2014, 10:35 AM

I posted a lengthy reply yesterday to everyone but it looks like it didn't take. I've been having some trouble with this for a while now.

Anyways...

I wanted to say a big "thank you" to all involved. This is more than i could have hoped for on this problem.

I bought the Mercedes and knew there was some trouble with her. However, despite asking over and over again what is wrong with her and them saying "nothing they know of", I bought it.

C-man: I have a Mercedes Chassis & Body Manual and I've tried looked at piecing the info available in the manual and not sure if it is the harmonic. Is there a website that shows the engine and the engine compartment components? Should I buy the Engine Service Manual? I bought a Haynes Manual and it leaves a lot to be desired.

Also here is the picture of the hemispherical Wrench I was talking about:

http://www.samstagsales.com/images/klann0366-7.jpg

cth350:

This what was looking for! Step by step instructions. Having read your write up I'm a little nervous. When I bought the car I knew that there were problems. For instance there is some rocker rot. The engine and compartment had about a half inch of oil and junk covering up the area. I suspected front crank seal leak but I took her to and Indie who said he would clean this up for $110 and find the leak. Took him and another guy or two over 4 hrs to do this and the engine still isn't that clean. Anyway, he confirmed it was the crank seal and O-ring seal (will ask about this later) in the timing chain area. He wants a smidge over $1000. I went to the Mercedes dealership and they said under $600.

I think I can do most things but not confident on this.

Right now my drivers door won't go up and will start tackling the seal shortly to see if I can do this.

Many thanks everyone on this I'm learning a lot about Mercedes and she's gonna be a real beauty when she is done!

Carpenterman · #10 12-31-2014, 01:09 PM

I'm not sure why you need that water pump wrench. As was stated, all you need to remove (other than the radiator and shroud) is the water pump pulley and it comes off with a 10mm wrench.

The front seal is a medium-hard job, IMO. You need some special tools (hub puller, allen sockets, 27mm socket, torque wrench, and some way of locking the crankshaft) and the seal and dowels. You can reuse the dowels but for as cheap as they are, I think it best to get new ones. Also, it might be wise to get new allen bolts for the pulley.

You may need a spacing ring, as well. You should at least turn it around to get a new wear surface for the seal. These can be hard to remove, if stuck.

In the Haynes manual on page 27 you will find an exploded drawing of the crankshaft with the front components. The seal is #21 but for some reason they label #20 as an oil seal, but it is really the spacer ring.

Follow CTH's excellent writeup and you should be OK. I'm sure that the crank bolt is 27mm, though.

cth350 · #11 01-03-2015, 11:44 PM

benz didn't publish an engine manual for the car. They were making lots of changes though the 60s, so the "complete" engine manual requires you to pick up the 50's service manual, the 60s service manual and then the addendums for the late 60s, early 70s car. It's a mess, but collectively it works if you get enough practice.

There is a CD from the classic center, if they still have it in stock that has the pieces kinda put together enough to make it work well enough. You can find cheap clones of it on fleabay, mostly bootleg, if the classic center no longer has the disk in stock.

When I first started on my 230/8 ages ago, the Haynes manual was all I had to go by and it worked rather well for me, even after I discovered the factory service manuals.

It's not that difficult to do if you have automotive work experience. I remember knowing less than nothing the first time I changed the oil. Oh, that was a long time ago.

Update your profile with a more accurate location and you might find that you live in the same town as another shop forum guy.

The last bit of advice is to buy decent parts for repair. Especially when you are getting rubber ones; real rubber is expensive. The cheap stuff contains too much sulfur and ages rapidly. (as you'll discover when you start replacing suspension parts).

-CTH

mercifiknow · #12 01-15-2015, 05:47 PM

Quote:

Originally Posted by cth350

benz didn't publish an engine manual for the car. They were making lots of changes though the 60s, so the "complete" engine manual requires you to pick up the 50's service manual, the 60s service manual and then the addendums for the late 60s, early 70s car. It's a mess, but collectively it works if you get enough practice.

There is a CD from the classic center, if they still have it in stock that has the pieces kinda put together enough to make it work well enough. You can find cheap clones of it on fleabay, mostly bootleg, if the classic center no longer has the disk in stock.

When I first started on my 230/8 ages ago, the Haynes manual was all I had to go by and it worked rather well for me, even after I discovered the factory service manuals.

It's not that difficult to do if you have automotive work experience. I remember knowing less than nothing the first time I changed the oil. Oh, that was a long time ago.

Update your profile with a more accurate location and you might find that you live in the same town as another shop forum guy.

The last bit of advice is to buy decent parts for repair. Especially when you are getting rubber ones; real rubber is expensive. The cheap stuff contains too much sulfur and ages rapidly. (as you'll discover when you start replacing suspension parts).

-CTH

I have the CD Rom looks to be the real deal. MB doesn't sell them anymore. I've been looking through it but don't find it useful. Maybe I'm doing something wrong or I expect too much. I'm not seeing anything about holding the gear ring in place in the Haynes manual. This must be one of those things they don't mention. It's interesting that you mention the starter as my starter took a dive in the toilet. Yea! More things I get to fix!

I'm probably going to send to MB to get it fixed (not the starter I think I can handle it). I guess I'll decide when I take off the starter.

As far as parts go, the MB dealership knows me well enough! I haven't bought anything other than MB and hope I don't have to. Although I know I will at some point.

Thanks for the help! Seriously. You all have be great!

I've got another problem that I'm elbow deep in..literally! I'm going to post another thread on this.