M110.988 crank oil seal replacement

[shabazmo]

I need to replace the crank oil seal on my new 1985 C123 28CE. Having done some research, I need a bit of help on the following.

1. Removal of the crank bolt. I understand that this bolt is very tight. Can I use an impact gun while holding the balancer or do I need to lock the flywheel with a special tool. If so where can I purchase this tool.

2. Ring spacer. I will need to remove the ring spacer. There is a special Mercedes tool but I also believe that a 2 leg bearing puller can be used. Can anyone recommend the tool and where I can purchase either. I also note that someone used a heat gun to get the space ring off. Can anyone recommend this method.

3. Any other critical procedural messages would be appreciated.

Thank you.

 

[Bellow]

I can possibly help you with your first question.
I was in the same predicament ie auto transmission and had to remove the crank nose bolt (but not on a Mercedes). I bought a £30 240V impact gun and that removed and re-torqued it without having to lock the flywheel. One reason for me to choose this route was it was during the first Covid lockdown and I was working alone and would really have needed someone to help locking the flywheel or obtain a locking tool - not really an option for my engine.
An impact gun is quite bulky and you may have to remove your radiator (if you haven't already). If you can avoid removing the radiator by locking the flywheel then worth considering. You have options.

 

[Bellow]

2. Ring spacer. I will need to remove the ring spacer. There is a special Mercedes tool but I also believe that a 2 leg bearing puller can be used. Can anyone recommend the tool and where I can purchase either. I also note that someone used a heat gun to get the space ring off. Can anyone recommend this method.

What do you mean by 'ring spacer'? The central part of the harmonic balancer?

 

[grober]

DIY: M110 Crankshaft Seal R&R - PeachParts Mercedes-Benz Forum

Like all seals in vehicles that are 20 years or older, the engine Front Main Seal is prone to failure. The rotary seal mounts in a housing and

www.peachparts.com

THIS IS FOR THE FRONTSEAL BUT SAME PRINCIPLES APPLY--tools to make the job easier are expensive- best to leave this job to a seasoned pro perhaps?

WARNING
IT APPEARS TO BE A ROPE SEAL!!!!!!!!!!!!!!

M110 rear main seal oil leak - PeachParts Mercedes-Benz Forum

I have a oil leak in the rear main seal. It has leaked for many years and im just kinda tried of having to add oil all the time and the mess it makes

www.peachparts.com

 

[MrGreedy]

I don't know about the seal, but I have also had good success with an impact driver and not locking the shaft when replacing a crank seal.
Access was good, as this was with engine and box out of the car (1.8L Renault engine, rather than Merc).

 

[Bellow]

I can possibly help you with your first question.
I was in the same predicament ie auto transmission and had to remove the crank nose bolt (but not on a Mercedes). I bought a £30 240V impact gun and that removed and re-torqued it without having to lock the flywheel. One reason for me to choose this route was it was during the first Covid lockdown and I was working alone and would really have needed someone to help locking the flywheel or obtain a locking tool - not really an option for my engine.
An impact gun is quite bulky and you may have to remove your radiator (if you haven't already). If you can avoid removing the radiator by locking the flywheel then worth considering. You have options.

Having read in Grober's linked piece that your bolt is torqued to 400-450N.m and mine was to 110N.m my post should be disregarded.
Any attempts to lock the flywheel will have to be thorough.

 

[grober]

https://clubgwagen.com/forum/viewtopic.php?f=18&t=1281https://clubgwagen.com/forum/viewtopic.php?f=18&t=1281

FRAUGHT WITH PROBLEMS!

W123 - nasty oil leak - South East specialists? | Engine

I've a bit of a leak on my 280TE, that a good look at appears to be a shot rear crankshaft seal. Annoyingly I'm told by one Mercedes specialist (who's now only into more modern stuff) that it's an engine and gearbox out job. Can anyone recommend any specialists in the South who may be less...

forums.mbclub.co.uk

 

[MrGreedy]

Having read in Grober's linked piece that your bolt is torqued to 400-450N.m and mine was to 110N.m my post should be disregarded.
Any attempts to lock the flywheel will have to be thorough.

Good spot!
I suspect the crank bolt on the Renault I referred to wasn't at 400Nm either!

 

[shabazmo]

Thank you everyone for your responses, especially Grober for the article. I replaced the coolant pump a few weeks ago so will be removing the radiator to do the job. I have a Milwaukee electric impact wrench which is mega but I do feel I need to find a way of locking the flywheel. The locking tool mentioned in the article is about $800, so thats out of the running. I cant bring myself to take it to a specialist. I need to have a go myself so will probably find a way of jamming something in the flywheel if I can find an opening to it.

I found a Youtube video where someone used a heat gun on the spacer ring to expand it and move it out a bit before using a 2 leg puller to remove it completely. I plan to do the job in the next few weeks so will keep you updated on my progress.

 

[Bellow]

Thank you everyone for your responses, especially Grober for the article. I replaced the coolant pump a few weeks ago so will be removing the radiator to do the job. I have a Milwaukee electric impact wrench which is mega but I do feel I need to find a way of locking the flywheel. The locking tool mentioned in the article is about $800, so thats out of the running. I cant bring myself to take it to a specialist. I need to have a go myself so will probably find a way of jamming something in the flywheel if I can find an opening to it.

Seeing as you already have an impact wrench then no harm in trying without locking up the flywheel. If the wrench can deliver the required torque, it will probably work without locking the flywheel. I'd not try the torque wrench/breaker bar though with anything less than that locking tool. There are 'universal' locking tools available relatively cheaply. They mount one of the starter motor (once it's removed) bolts. >> universal flywheel locking tool - Căutare Google

I found a Youtube video where someone used a heat gun on the spacer ring to expand it and move it out a bit before using a 2 leg puller to remove it completely. I plan to do the job in the next few weeks so will keep you updated on my progress.

I'm guessing you are not dependent on the W123 for daily transport - in which case, whatever it takes, you'll find a way to remove the spacer. Some penetrant and heat will help. I take it you can obtain a new spacer? And Belleville washers? The spacer could be turned (assuming the wear is off centre) and re-used but new Bellevilles I'd deem essential.
Good luck - it's a pretty involved job you are taking on but no reason you can't accomplish it.

 

[grober]

SOME FOLKS HAVE USED THE STARTER MOTOR ORIFICE [ MOTOR REMOVED] TO ACCESS THE RINGEAR WITH HOMEMADE LOCKING TOOLS

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[shabazmo]

Grober, I am fairly good with tools but fabricating a locking device is a bridge too far for me. Bellow, If I don't lock the flywheel the engine will just turn as I have an automatic which has very little resistance to turning. I need to hold that flywheel.

I have manage to dismantle a couple of panels and now have access to the flywheel (brown with green paint) The panels are at the bottom of the engine. see photo. The teeth are just hidden but I managed to get a 5mm allen key trapped between the teeth and the housing, then used a 24" breaker bar with a 1m extension from my trolley jack. I realise that the breaker bar just flexes and I will need a 3/4" or a 1" breaker bar. But before that, I will try using my impact wrench. I just need to find a free day to remove the radiator, bumper and bits.

Yes, I am lucky that this is my spare car.
o

 

[Bellow]

Bear in mind that at a 6'' radius the force when 450N.m (300ls.ft) is applied to the crank bolt (and it may require more to 'break') is around 600lbs. Breaking a casting or stripping a tooth is easily possible. Remember also that you probably have a flex-plate not a solid flywheel. You do not want to distort it. The torque convertor is constructed from thin steel plate - another vulnerability. For the sake of the £10 or so for a universal locking tool I'd get one and whip the starter motor out to use it. It will also give you more options when it comes to re-fitting the bolt. I managed without one but at 74lb.ft the torque was a lot less and my crank is probably heavier than yours. Anyway, the tool wouldn't have worked for me as my starter bolts on side-saddle.

 

[shabazmo]

Thanks Bellow, that did cross my mind and I was also thinking of using a holding tool resting on a hard surface and attached to the harmonic balancer.

I am not familiar with a universal locking tool or how to use it. Can you point me in the right direction. Thanks

 

[Bellow]

Thanks Bellow, that did cross my mind and I was also thinking of using a holding tool resting on a hard surface and attached to the harmonic balancer.

See pic below for the tool I used when I was refitting the balancer to the crank and it had to be pulled on with a bolt. Only use on the inside of the rubber ring and be aware that if there is significant torque at the bolt threads (as opposed to the bolt clamping the balancer), all (or most) of the torque will be going through the keyway. From memory, I probably used it in the final torqueing with a torque wrench.

I am not familiar with a universal locking tool or how to use it. Can you point me in the right direction. Thanks

Have a look at them here >>

universal flywheel locking tool - Google Search

As far as I know, you remove the starter motor then bolt the tool using one of its bolts and snug it up to the ring gear then tighten. Better than risking bursting something in the bellhousing area (a carnival of pain!) and more control when it comes to reassembly.

 

[shabazmo]

I had a good look at the starter motor and one of the bolts is near impossible to access unless I remove the exhaust down pipe and even then it looks difficult. I remember in the 70s, I used to wedge the breaker bar against the chassis and turn the engine via the starter motor to loosen the crank bolt. just a thought at this stage.

 

[Bellow]

I had a good look at the starter motor and one of the bolts is near impossible to access unless I remove the exhaust down pipe and even then it looks difficult. I remember in the 70s, I used to wedge the breaker bar against the chassis and turn the engine via the starter motor to loosen the crank bolt. just a thought at this stage.

That might work - but 450N.m is a considerable torque to break. And you will still need a method when it comes to refitting the bolt.
My smart's crank bolt had an absurdly high initial torque then an additional 90 degrees of rotation. I didn't have an impact wrench at that point and the engine and gearbox were out of the car. It was a pig of a job. Restraining the engine and box took all my ingenuity.

Try your impact wrench first against the inertia of the crank. It's the gentlest method re forces in the bell housing area and if it works taking it apart, it will work on re-assembly. The removal part will give you a 'feel' for reassembling if you choose to use the impact wrench for that.

 

[grober]

How to Remove Starter, 280E---- Heeelllppp!!

www.benzworld.org

 

[shabazmo]

Thank you Grober. I will update the threat in a couple of weeks when i start the job.

 

[shabazmo]

Today I finally decided to do my crankshaft oil seal, and therefore tackle the crank bolt. My first try worked a treat. I used my Milwaukee electric impact gun. Model M18 FHIWF 12 and after about 15 seconds, the bolt spun off. I didn't even need a holding tool for the harmonic balancer. So about 20 hours of research for 15 seconds of work!

The harmonic balancer was very very tight on the crankshaft and I used a hydraulic puller to get it off. I am not sure how I will get it on. Maybe stick it in the oven for a while. Any thoughts?

The ring spacer slid along the crankshaft quite easily, but the last 25 mm was stiff and I used a light weight 2 leg puller to get it completely off.

I am also thinking about installation and how I get the crank oil seal over the crank spacer ring. I am thinking of first installing the oil seal and then sliding the ring on the crankshaft and into the oil seal. Again, any thoughts please.

Thank you all once again. What a fabulous support this forum is.