I think maybe you are confused about how to do it. On the 451 you slide it to touch then a further 3 marks (I think that is 6 mm).

On a 450 you use a spring balance and apply a preload before you tighten the bolts.

Who replaced the actuator? If it aint right then go back and whinge.

Is it a genuine Sachs actuator?

 

Thanks for your response. I'm simply following the instructions from evilution.co.uk.

(Clutch Adjustments | Evilution)

It was a mobile mechanic as the car wasn't mobile so I had to have them come to me.

Yes, it is.

 

Well your post is in the 451 forum and your link is related to a 450.

We still do not know which you have but let us assume you posted in the 451 forum because you have a 451 and you followed the instructions in your link then I am surprised that it works at all and that the thing has not completely failed with some mechanical problem.

Evilution is not a god. There are a lot of mistakes on there so be careful.

Which car do you have?

 

... it says the following.

God forbid I assume they're accurate lol. It literally looks exactly the same, and I have a 451 lol.

Obviously they're not "Gods" but I've seen them referenced here on this forumn countless times and never heard anything bad about them lol. It's been working for almost a 1000 miles since changing, but I just feel it could be smoother. Not sure why the negativity as it doesn't seem like you're not trying to help yet criticize.

Thanks for your time and input dude. Have a great year.

 

I gave you the links as you do not seem to be able to tell the difference. The two clutch actuators are installed with an entirely different set of instructions that are not compatible with each other.

If, as stated on the page you linked, you apply 50 newtons of force to a 451 actuator then you will break something.

Why ask for advice if you do not want to believe what people tell you?

Good luck.

 

I'm not sure what you don't understand as the link you provided for the 450 is a BROKEN LINK, and the other link is to the same actuator I have which if you search this forum will see there's multiple posts explaining how to adjust it. It's not a set 3 lines, maybe you're mistaking the 3 lines on the speedo when actuator goes as thats why you mark the previous position. lmfao... thanks lol. I applied the method with 50 newtons this morning and seems to be much better. Again i was simply asking if the actuator would need to be retaught if the connector wasnt unplugged. Wasnt asking for broken links and a link to the product I already have lol.

 

So you have applied 50 newtons to a 451 actuator and tightened the bolts?

Is that correct?

The 451 actuator has a self adjuster built in. If you cannot push the square arm into the actuator quite easily by hand then the actuator is faulty. As far as I can see if you are able to apply a pull of 50 newtons with the mounting bolts loose then the arm is not retracting into the actuator body which sort of suggests you have a faulty actuator.

There is a long thread on here that shows the internals. It uses a wedge shaped piece of metal that pushes two rollers outwards when pushed from the actuator side but when the wedge is retracted (clutch engaged) the rod that engages the clutch arm should be free to move in and out.

 

Yep, followed this article without any issues! Didn't need to reteach bite point either.

Clutch Adjustments | Evilution

www.evilution.co.uk

 

Out of interest I just measured the force required to make the push arm retract into the actuator body on a new actuator and it is exactly 50 N. That is the spring inside the push arm.

If you did use a spring balance then 50 N is the maximum you could apply. Any more than that and the arm will simply retract.

I suppose it was done that way deliberately because of the problems the 450 gave people with that method of setting the position. On the 451 there is no need to go to that trouble because the 50N spring will allow for lots of tolerance.

 

Out of interest I just measured the force required to make the push arm retract into the actuator body on a new actuator and it is exactly 50 N. That is the spring inside the push arm.

If you did use a spring balance then 50 N is the maximum you could apply. Any more than that and the arm will simply retract.

I suppose it was done that way deliberately because of the problems the 450 gave people with that method of setting the position. On the 451 there is no need to go to that trouble because the 50N spring will allow for lots of tolerance.

Yep, so the article does seem correct then?

Drove it around all day delivering Doordash and seems much better.

 

No, the article is for 450 only. Mercedes say 3 marks. I think it adds up to the same thing and that it is designed that way but no special tool is needed for the 451 to set it.

Wherever you put the actuator it should be around 50 Newtons. I think that the three notch thing is a minimum so that the adjuster can compensate for wear on the clutch and settling of components after a few actuations.

I am going to try it with one of mine. I reckon that anywhere from three notches to the end of travel should result in the same clutch behavior without re-teaching.

 

What would happen if you pushed the adjustment to the max (meaning no more notches left) , I feel like when I was adjusting mine I have no more room to push further, only one notch left

 

Can you push the arm back into the actuator. If you only have one notch of movement left then I suspect your arm is stuck further in than it should be.

It should be possible to push the actuator "rod" back into the actuator by a couple of inches and it springs back out again.

 

For what it’s worth, there is a secondary procedure that can be performed when replacing the clutch actuator, but it requires a Star Diagnostic machine or similar. It takes only a few minutes and teaches the car the clutch drag position with respect to the actuator.

 

That should be done along with correct fitment. It needs both to be absolutely correct.

 

so basically he has to go to a MB dealer

 

Not unless the adjustment is really out of whack.

 

Well so far everything seems to be working, no lines on the dash, I didn't even disconnect the battery

 

So you have only 1 adjustment notch visible ?
How many notches did you have before?
Why did you have to adjust? What codes did have? Did you replace your actuator / re-grease the old one ?

 

I would leave it as is if it feels OK to drive.

Teaching the clutch is not straightforward and if you are paying a Merc garage to do it then it is possible it will come back worse than it was when it went in.

My 2012 will not teach, it fails every time I try no matter what software I use to do it.

 

Do you have any theories on why the reteach fails on your 2012? Assuming your transmission input shaft rpm sensor and your engine rpm sensor are working correctly, and your gearbox is able to switch to neutral, the only other component that can affect the reteach is the actuator itself, no?

Is it possible your actuator has lost the ability to control the extent to which the arm is pushed out? i.e, the actuator is just not able to stop at the bite/drag point, and thus the reteach process fails because it cannot find a way to repeatably and gradually increase the input shaft rpm.

Best I can tell, the worm gear drive relies on static friction to hold the arc gear (and thus the arm) at an intermediate position between fully retracted and fully out. Maybe the tip of your motor's worm drive is worn out and not providing enough friction?

I apologize if i'm being dense - i'm new to the analog world of car maintenance and might be making some incorrect assumptions about how the reteach process works.

 

I just posted this in another thread, but it might help here. If the car is experiencing rough shifting, a throttle body reset might help.

• Turn the key to “on” without starting the car.
• Push the accelerator all the way to the floor and hold for five seconds.
• Continue to hold the accelerator and turn the key to “off.”
• Release the accelerator pedal.
• Wait until all the dash lights turn off.
• Start the car normally and try a test drive. If the car was giving hard shifts before, this procedure should help.

 

I have P2802 and P0949 . 2013 Pure.
Just bought it a month ago with money light on and occasional 3 bars of death/no switch in reverse.
I opened the clutch actuator, cleaned with electrical parts cleaner, re-greased.
After ECU reset with a better scanner , cel turned off and wouldn't comeback , including 3 bars of death. I was able to pass state inspection.
However as soon as I hit bumps and cracks on the road ,or do a sharp turn, the cel will come back on.

I'm wondering if there's damage to clutch actuator wire harness... Where could be the possible damage to look for?

 

I think the issue is solved.
After a reset with a more sophisticated scanner I still had intermittent cel and 3 bars of death after hitting bumps on the road.
Then I replaced the actuator with one from Amazon and so far so good.
I think the old actuator wires are probably corroded. I'll try to open it up again and see if it's possible to repair.
So in my case, the fix for P2802 and P0949 is a combination of new clutch actuator and a reset with a proper scanner.
No need for Mercedes Star diagnostics.

 










Update......... I got the three bars of death and I was stranded for about an hour before the gears engaged ,I was only able to drive if I switch the car into manual mode ,I was only able to use up to gear 2 so it took me about an 1hr to get home while driving 20mph. Anyways I ordered another clutch actuator and installed it today, I didn't disconnect the battery and I put it on the same markings , I didn't even have to reteach anything ,it just worked right out of the box, it was Sachs 3981 000 066 from eBay for $340. only time will tell if I get the 3 bars of death again

 

Congrats!
If check engine light is off and there are no pending codes then it's gonna be fine.

 

I adjusted it last week without disconnecting the battery with no issues. Much better now.

 

Yeah, high pressure undercarriage wash is not a great idea around such small Smart engine or any engine compartment.
If check engine light went away, then you're fine for now.

Stall in 1st gear + trouble codes

My car had that weird problem where it goes into neutral from 1st gear automatically a few months ago. It just happened again tonight and this time I had a scangauge II connected, here's the codes that came up: P073F - Unable to engage gear 1 U3FFF - ? U3F00 - ? P0008 - Engine system...

www.smartcarofamerica.com

 

Yeah, high pressure undercarriage wash is not a great idea around such small Smart engine or any engine compartment.
If check engine light went away, then you're fine for now.

Stall in 1st gear + trouble codes

My car had that weird problem where it goes into neutral from 1st gear automatically a few months ago. It just happened again tonight and this time I had a scangauge II connected, here's the codes that came up: P073F - Unable to engage gear 1 U3FFF - ? U3F00 - ? P0008 - Engine system...

www.smartcarofamerica.com

Thanks.
I live where there is more salt than asphalt on the roads at times. Will have to wash with high pressure gun instead of automatic method going forward I guess- being mindful of the gear actuator.