The OEM replacement pulley I bought easily slides on and off the end of the crankshaft. This doesn't seem right to me. Everything I've seen and read says that the pulley should slide on half way at the most. Do you think I have a bad pulley?

 

Do you have a micrometer? I would say measure the crank and see if your within spec. What brand pulley did you go with?

 

I don't have a micrometer. It can spin on the end of the crankshaft. I went with a cheap Bapmic from eBay. What should the tolerances be?

 

There is a build difference I read somewhere that certain mini may have a different size crank. Just remember it should not slide on. There are some articles about this issue.

 

I bought my daughter a new 2015 F55. We have the same problem. Hard to believe these don't last any longer than 53k miles/5 years and that they cost nearly $500. I have a 1968 small block chevy 52 years old/180k miles and the harmonic balancer is still going. There is no belt torque on the chevy, but still, these should last longer. It looks like they had problems with the Gen 1 Mini's pulleys too so I would think they would have made these better.

Is the consensus that we don't need new bolts? I know some BMW's use aluminum alloy stretch bolts but these appear to be steel. Also, the torque system seems odd. Is it really 40N-M plus 120 degrees?

 

I'm not sure about the F55 but Gen1 cars need to have there bolts replaced with new ones.

 

I used new bolts since they were reasonable and I didn't want to risk the pulley coming off. I had a hard time holding the engine from turning while tightening the bolts. I was able to torque them to 40n-m with a torque wrench but I could not turn them the additional 120 deg with a wrench. I put some tape on the socket and used an impact driver to turn them the 90-120 degs. It worked well, but you need a marker so you can see the angle. The pulley is a different design than the one that failed. I hope it lasts longer than 53k miles.

 

I installed the ATI Super Damper yesterday, using this technique:

Laser Tools pulley remover > https://www.lasertools.co.uk/product/6142

I only jacked up one side of the car, put the gearbox in 6th gear and used a large lever on the axle bolt to give resistance when torqueing the new crank bolt down to 116Nm (85 ft lbs).


More pictures of the installation: https://www.northamericanmotoring.co...rogress-8.html

 

A size mismatch has happened if the pulley slides right on. Most likely, the pulley is the wrong inner bore size.

We had to make a pass-thru jig that bolted to the balancer and wedged itself to the ground. It had a hole cut so the socket wrench could tighten on the crank without allowing the pulley to turn.