Crank pulley / vibration damper
 

Need a little advice just had my 2008 cooper s in the dealer where they told me that my crank pulley needs to be replaced because it's vibrating and starting to cut the belt. (I do hear a little chearpu g from the belt)

I would prefer to replace the crank pulley myself as I am able to do most mechanical repairs myself, and don't want to give the dealer $550 in labor costs on top of the $430 for the crank pulley if it's something that I can do myself.

What has me a little concerned is I can't find a replacement pulley everything appears to be for R53, is there any recommends for where I can get a replacement. Also figure that while I have crank pulley off might as well change the belt and seal.

My other concerns is doing this repair myself will I require and specials tools or can I rent the standard pulley puller from local auto parts store? Also I have seen some videos with people changing the pulley remove the 3 smaller bolts and larger center bolt as doing so it looks as through the pulley may rotate would this cause any timing problems do I need to make sure that the crank pulley doesn't move during the processes?

On a side note dealer also told me valve cover has a small crack so if you can recommend a replacement as well should be a pretty easy repair.

Thank you
Kevin

The worse thing about replacing the pulley on the R56 is getting the belt off. But it's really much easier than the R53 as it isn't pressed on. Just 3 torx bolts and it comes off.
http://www.waymotorworks.com/image.php?type=T&id=17919
http://www.waymotorworks.com/cranksh...9-r60-r61.html

r56 vibration damper (crankshaft pulley)
 

At least your dealer was able to find the solution to your problem. Long story short after going on vacation and getting my vehicle towed and repaired at 2 separate dealerships for the belt breaking, the problem still did not disappear. :mad: Only after I arrived back home and took it for a drive up the mountain did the belt come off a third time; I drove it back home with the broken belt and took the car apart myself to find the crankshaft pulley out of round and a little shaky. Also found where the pulley hit the side of the engine, you can see markings on the back side of the pulley if you look close on the edge near the rubber damper.
Figured I would machine on out myself. Did a little research and some people are for it and some against the idea of a lighter pulley for the crankshaft. Many companies such as Alta and Craven have lightweight pulleys made from 6061-T6 for the R53 and I have no heard any complaints from their customers from all the reviews I have read. So I will definitely end up machining one for the R56 but I will not be using 6061 because 7075 is way superior (http://www.makeitfrom.com/compare/60...5-T6-Aluminum/) and after working with both of the materials when I was in the Air Force I would say 7075 is much better.
It will take me some time to make it. And in the meantime anyone have any comments? Anyone think it is a bad idea?

update on last post.
 

I did a little research on cost of some raw materials. 7075 is a lot more expensive than I bargained for; no wonder people tend to use 6061. So, I guess I can still go with 7075 but it will cost me $210 for a 6 dia by 6 in piece :eek: or $369 for a foot long piece. 6061 they have a 5.75 dia by 6 in for $102 and $172 for a foot long. Then I looked at 17-4 ph S/S for a 6 dia by 6 in piece is $50 and $91 for a foot long. All these numbers come from McMaster-Carr, an online site for various metals. Guess I need to make a decision on which to go with or just stoop to buying the part.

How are you putting in the rubber and vulcanizing it. If you get it right great but if you get it wrong and reinforce the harmonic waves you could bust the crank or shorten engine life. Balance is a bit easier in 4 cylinder engines but harmonics are tricky. some where I have/had an old book about this stuff it can be the case sometimes where more weight produces more power its all about where you can put it though. I was thinking of using an instrument pick up and a phone orientation sensor to get some vibration data but it would be crude at best I think. The place to start might be with someone who has a good stock running car and get some readings. then try yours, I would think without some some good measuring tools, and math, and software, it would take quite a few tries to get anything good but maybe you can ask around. Fearless is good just understand the risks. What kind of lathe do you have.

I believe he's going for a all aluminum pulley with no rubber.

Make a two Part harmonic balancer groove the insides of each side for mechanical lock find an elastomer specialist to do the flexible part choosing the type thickness and hardness would be key. Yes its crazy work but you were talking about machining so I'm guessing you have some skills. If you do come up with a good part you might do well with it. Our stock cast steel cranks are pretty nice but all that torque causes a lot of flex even if the components dont break helping to reduce harmonic overload can only make a better engine. There are custom harmonic balancer producers we would need a few people at least to try and get them to produce a balancer then there is an issue of what build you make it for. Again lighter is not always the goal here but better is.

crankshaft pulley
 

Ya I was thinking about making a solid piece and not a two part pulley. Not sure the name of the lathe in the Engineering department I will be using. But I will be using the tailstock to make sure I am cutting on center. Need to ask if they have a hardness tester at school to get right properties of the stock if I were to make a 2 part. I wish there were a set up blueprints for this, it seems heavier on one side than the other. I am drawing it up on AutoCAD. It will just take me some time to make cause of classes and family.

Hi I have been wishing I measured weighed and did a full cad drawing of my engine when I had all the parts out, but I guess reverse engineering off the stock damper is an OK place to start, of course exactly what material its made of would be great. I think you need to guess at a number for crank flex force of coarse its the harmonics that can be trouble if/when you get reinforcement it could add up considerably. Do you have any finite element software? Try to estimate the stock parts strength then max crank force add in a 2 to 1 safety margin and see if it makes any sense. As to solid vs elastomer damper I’m all for experiments and yes there are aftermarket solid replacements I have never used one and advocate for a true damper, but its interesting that the stock damper is held on with three rather small bolts those could be easier to model in fact you could set up a test of the actual bolts in action under load with a long bar acting on a disc simulating the damper then work from those numbers. So are Plans closer to reality than the physical object I like to believe that chaos is transcendent you want to struggle with it.

I believe in a two part damper you can make the inside as light as possible and the outer ring is the heavy part. Visualize the crank flexing and follow the motion through the elastomer to the outer ring. If you get a good hardness number from the stock elastomer it may be possible to math infer the harmonics it was designed for. You could make your own elastomer hardness tester and calibrate off a know material like skate board wheels or some samples O-ring chords.

Isn't the dealer on the hook for repairing the damage? I know you probably don't want to take it back to the dealer, at least contact Mini USA about the issue.

Hi I don't mean to over push the idea of making a two part pulley but this kind of stuff is so fun. After looking at my pulley damper I found 410-450hz printed on it and it does look to be pressed together I would guess the hardness of the elastomer at about 70 on the duro meter scale there are quite a few different elastomers to play with so you could make up a damper and try different elastomer elements.