Jakpro1

Bout to do my first home install of a pulley and was curious.

I have all the necessary tools, new bolt, special crank tool etc.

Question is

Why do we need to do the flywheel lock again.

If I am keeping the pulley secure with this tool....(see below)

While torquing with/ or unscrewing with breaker bar....do I really need to lock the flywheel.

LAST thing I wanna do is mess something up. Just was curious if flywheel lock is essential and why.

Thanks guys!

Hammer Down

This is what Pat @ PTE said but he did not clarify what would fall under the term "critical install"


This is the way I install the new HBs. I set the OEM one to 37 – 38 degrees ATDC. Remove it , Mark the new one at 37 – 38 degrees ATDC. Feel for the key engagement. , Because of the tighter fit , it may not bottom out against the oil pump drive sprocket , during a hand install .So I use the old bolt & the 1 1/16” socket adapted to a 1/4” drive ratchet to bring it in the rest of the .310 , That way you feel it slide into place. Remove the old bolt install the new one , Tighten to the new Higher torque spec 180 Ft lbs & stretch 90 degrees .For real critcal installs I remove thw motr mount assu & Starter motor. I intall a flywheel lock , with the motor at 37 - 38 degrees ATDC. It is a pain in the A$$, and Time consuming, But I know it is correct.

GT-ER

I would not waste my time with that tool and I would just lock the flywheel. It's too much torque to do it properly and easily with that tool.

Hammer Down

My tech has the same tool that they use in the shop and he will soon use that tool on my car.

Hotrod-Realtor

This from a guy with a lot of experience in this department. I agree with GT-ER, lock the flywheel and skip the crank holding tool.
Lot's of European cars use flywheel locks to keep the crank from turning. I was surprised to see the pulley holding tool for the job.

If you have a third hand, you could get someone to help keep the crank from turning using both the pulley tool and a prybar or flywheel tool.

komp55

FWIW, the MB WIS procedure for the pulley calls for the use of the tool pictured, not locking the flywheel. I assume the MB engineers know what they're doing.

whipplem104

komp55 is correct. Mercedes specifies the pulley holding tool. They do not want you to use a flywheel tool for this job. The flywheel holding tool is for tightening the flywheel bolts.
I and many others at dealers and other shops around the world have replaced an unbelievable amount of crank pulleys from campaign and failures and use the pulley holding tool only. I use a short piece of pipe to the frame rail to support the tool and free up my hands for the bolt. Some of them are so tight I have snapped several ratchets in half over the years. Main thing as mentioned is make sure the key is lined up. I always slide on a little and make sure I can not turn the crank pulley one way or the other before going further.

splinter

I’m retarded enough to use MB’s tool when swapping crank pulleys.
Read of jangy’s ill-fated installation when first joining this forum.

Jim, though I appreciate your DIY spunk, respectfully suggest you farm this job out.
We hear your voiceover spots all over the dial. :D

E55W

Where can I buy the tool for the crank pulley

lowprofile

Jim, it is either one or the other, not both. If you have the tool, use it.
If you don't have the tool, the workaround is to lock the flywheel.

GT-ER

I've done the pulley swap a few times and I do it alone which makes the use of the MB tool a BIG issue. Another issue is that some pulleys, like the EC ones, do not allow for the use of the MB tool so locking the flywheel is a MUST. Also, using the oem torque of 140ft-lbs+90* is a FAR cry from EC's torque recommendation of 275ft-lbs + 90*.

Locking the flywheel is easy enough as it is and will allow a person to tighten the bolt by himself without any assistance.

Hammer Down

If you lock the flywheel there is a possibility that you could crack your crank because you putting that stress on the crankshaft instead of the pulley. Use the tool and potentially save yourself a big headache. Just my .55

lowprofile

BTW, are you going bigger or back down?

GT-ER

GOOD LUCK cracking the crank...LMAO.

Hammer Down

Possibility was the keyword, call up MB and talk to a tech and ask them why do they use that tool.

snail45

I used the crank pulley tool when changing mine. Worked great and had no problems. Had to modify the tool a bit to fit the holes in the ec pulley to get it off. Put an asp pulley on and the holes lined up perfectly.

Hammer Down

That's because ASP uses the OEM dampner

GT-ER

Yes....0.000000000000000000000000000000000001 percent chance. There is also a change that the tool can break, causing you to hit your head with the break bar and kill you...and I'm sure that percent is considerably higher.

Anyways, MB is also the one that states that you must lower the entire rear subframe to swap out an airmatic spring when is reality there is no need to do so.

Shifter

Really? How do you get the small metal pressure resiviors out without dissconnecting the hose going to them?[quote=GT-ER;489733

Anyways, MB is also the one that states that you must lower the entire rear subframe to swap out an airmatic spring when is reality there is no need to do so. [/quote]

Hammer Down

you may be right about the breaker bar, but I was just offering a piece of advice that was given to me from a tech. I will say this I will not be locking up my flywheel when the time comes to change the pulley.

GT-ER

You don't, you disconnect the hose and then reconnect it. I have a friend that's an MB tech and he says he's done it a hundred times without a single issue.

GT-ER

And that's fine, but if a tech gave told you that you could crack the crank shaft...I would honestly question his ability to work on your car.

Hammer Down

Nope I wouldn't question it, I understand its your opinion but I wouldn't want anyone else working on my car and that's my opinion. Again I was offering up some advice from a friend/tech. There's no need to try and insult me or my tech.

GT-ER

I'm not insulting anyone...I'm just saying that he is 100% incorrect and his claim is 100% baseless. Again, nothing wrong with using the tool just like there is nothing wrong with lowering the subframe to change an airmatic spring. But don't post claims that are absolutely incorrect.

Hammer Down

how do you know if that's what or how the MB techs are trained? I don't know either but if you're taught something in training then that's the extent of your knowledge is what you are trained. correct?