vrus

I wanted to start this thread because I wanted to provide some more information on Crank Pulley damage that results from an improper install.

There was a thread that was started a few weeks ago where we were discussing whether or not a VRP pulley suffered damage either from an improper install or because it was defective.

The reason I am making this post is because one of the members on this board had the same damage occur to his STOCK E55 Crankshaft pulley. Whoever installed his stock pulley did not follow the proper procedure and it resulted in keyway damage.

Below are 2 photos showing the damage to the keyway on his stock pulley.





Notice how the damage is almost identical to what happened to the VRP pulley that was discussed here: https://mbworld.org/forums/showpost....1&postcount=45

If the bolt is not torqued down properly, the pulley will wobble, and the back 0.75" or so of the keyway will get damaged as shown in both sets of these photos.

LZH

Thanks for posting, perhaps MBZ should recall every crank pulley out there and make sure it's not defective - LOL
Wonder how many would come back with no bolts!!!!
Sorry, I had to
Anyway, I'm sure when this happened you had a nice sight of relief....not to worry - I for one never doubted your product.
Perhaps to strengthen your case even further you should intentionally install a pulley the wrong way and then take photos after it runs for a bit. Something tells me the photos would look almost identical to the above.

splinter

I fear few bolts, as my son and I regularly enjoy the satisfaction of twisting wrenches in our garage.

Pleased that Vadim and his consummate technicians installed its crank pulley, however.

jangy

I think some of the issues are in the process used, including the use of the tool to hold the pulley while TQing vs using the Tranny lock method. I already know what MB says to do, but i would personally have a hard time TQing anything to those levels with such a short wrench (tool). I have seen it used once at a dealership and even then, two people did it and they slipped a breaker bar over the tool to get better TQ on it. Every other times I have seen it done, including when James at Creative installed it, was by using the tranny lock. That is how James said Ken of RennTech trained him. Given that, i don't think that just the method is the issue but I do think that we are getting waaay too many bad installs lately. Sure, we had fewer pulleys going on a few years ago, but how difficult is it to pay attention? You know it is a sensitive install that MUST be done right. It is a basic task, but it MUST be done to a T, so why not slow down and do it right?

jangy

Also, I still think any engineer could take a look at that pulley and tell you exactly what type of force made it fail just by looking at the directionality and pattern of the metal.

LZH

DING DING DING !!!! I think one of the reasons that many of us are here is because we are so meticulous about our vehicles...that's why many of us do our own wrenching because we know it gets done, to a T as you said. More often than not when someone else works on your car, that is not always the case and procedures are overlooked and corners are cut. The photos don't lie and it's really too bad because the smallest mistakes can have catastrophic results. Especially when you are dealing with something as highly engineered as an AMG motor.

MB Fanatic

Victor,Vadim, Sunil and gang,

I have full confidence in your proucts and have nothing but praise for you gentlemen. I hope this helps settle that the Pulley must me installed correctly or there will be damage. I hope others take notice of this thread and learn from their mistakes on installing the pulley.

psuball1

My Renntech pulley has a slight wobble since my install in Feb. Should I assume my car is damaged? I am getting a new pulley after speaking with Ken and James @ Creative but is this going to help the issue?

I have not had any issues with my car but does that mean that everything is OK?

stevebez

Why would the key way only be damaged at the tip of the keyway rather than down the entire keyway if the bolt was not torqued down right - does this mean when the pulley is installed the key is situated at the rear of the crank slot (back of the pulley) and from the get-go is under stress and the pulley gets the dent and then cannot move?

I actually think the pulley gets the dent when the bolt is torqued down when the pulley holder tool is not used correctly, or more than likely when the tranny lock method is used. Using the tranny lock method is - to me - looking for trouble. The torquing and stresses are completely different when the pulley is held fixed with the tool than when the crank is being held fixed, with the torquing plane very offset from the locking plane. With the pulley tool they are as close as could be in one plane.

I think with the tranny method the pulley bolt begins to grab on the pulley when being torqued, the pulley twists on the crank snout and then damages the keyway.... I can't see why one would risk doing it like this.

We all know what benz say.... why would they have a special tool if they could just lock the tranny up using a bolt??

So that pulley damage looks like faulty install caused during torquing to me....

theboogers

BrianS came over last weekend and we checked out the wobble in the VRP pulley. it does go away when the revs are upped a little. i thought it would be a optical illusion making the wobble disappear but brian checked out and it does balance out under higher RPMs. the belts look and track fine.
the squeak is loud upon start up with the VRP pulley wrap and i am getting a new idler pulley to replace for a start. still trying to isolate the correct squeak maker.

supre55

Ken Rudy? Solid guy...

CWW

Don't sweat it.

I think it was obvious to everybody what was going on in the other thread, especially after it came out that you had requested the bolt but instead it got "thrown away".

rflow306

I agree with you 100%, the pulley should be held otherwise the key will be subjected to the force being applied during the install.

psk145

my first gen. pulley also had a wobble. After sending a second pulley, that one wobbled, so Ken got me a new dampened pulley, and it also wobbles.

So I guess its safe to say that a slight wobble should be OK.

racetested

I'm having trouble understanding all the confusion here. I believe Jangy mentioned here and others have in the last thread about checking for accuracy, etc. that any machinist/engineer can do. We do have tools for this and don't live in the stone ages.

1) Check material hardness for accuracy.
2) Put a dial indicator on the pulley and check for variance between factory and aftermarket wobble.

I'm sure there are few other things that can be done that I may not be aware of but a machinist/engineer knows.

jangy

It ain't ok and you never even had your front seal checked.

jangy

yes, one in the same.

al@cpt

Here is a picture of a stock pulley removed from a stock low mileage E55. This pulley was only removed. It was never reinstalled.

Marcus Frost

Gents,

Something smells very fishy here. It's not VRP, and it's not CPT... something is smelling awfully fishy from Germany. I am seeing MORE and MORE evidence of pulleys from MB that have never been touched/modified wobbling/damanged. We have now a picture of a never re-installed pulley (that wouldn't be subject to install/torque errors) having keyway damage. Now, I, like everyone, want to believe this hand-built business is great and AMG is the best engine builder out there - but I have seen some very f'd up things from OEM manufacturers before - and I think at the very least we need to start looking into the AMG/Factory side of things a bit more closely.

The plot thickens.

-m

chiromikey

my stock pulley wobbled ever so slightly and so does my asp and i don't think it's a problem to be overly concerned with.

my stock pulley also had damage to the keyway when it was removed. i personally don't think it's an installation problem but more of a problem when the s/c kicks in and causes a large and abrupt tq spike against the crank pulley. this could be another reason why mb designed the new s/c clutch to engage smoother (you know they wouldn't do it just for our comfort).

Marcus Frost

chiro,

It may not be a big deal when there's a slight wobble, but that slight wobble can be exasterbated by larger pullies and multiple installs. A wobbling crank pulley, I think you will agree, is not a good thing. A slight wobble may not be the end of the world, but I've seen some pretty significant wobbles.

We may need to look at things from a whole new angle - meaning part of installation may require observing stock wobble, checking the stock key/keyway, and make adjustments as necessary, because it could be what you are saying or it could be some of these engine builders in Germany may be cutting corners

-m

theboogers

checked my asp pulley removed for install of vrp and there was no sign of damage to keyway. slight wobble does exist with both pulleys. My stock pulley looks clean and no damage to keyway.

psk145

no, I did have it checked. It was actually leaking and replaced

supre55

My Renntech pulley had a wobble... but it was laminated out of plane ever so slightly. No key way or crank damage though. I now have VRP without any wobble. Pretty sure George did not fubar the install.

waxking1

I just checked my stock pulley. It looks just like Al's picture. My stock pulley had never been removed before. Also I have a slight wobble in my Renntech pulley at idle and have never had any belt trouble.