New Repairs and question

[bmrboi2]

Originally Posted by StefX

Just after replacing front brake pads I had a bunch of new non related fault symptoms.. sighh

I am thankful I bought Extended warranty! had the beast since 2013 and no problems until now.

at 61,000 miles..2011 e70 N55

2. Rattling sound from front end but just reaching 2000rpm and up to 2300 and then goes away, idle and driving, slight change with A/C off but not much.

2. Suposedly water pump (makes sense for the overheat) I thought it was the tensioner..

I have a rattling that is very similar to what you are explaining that comes and goes as it pleases. Are you saying that replacing the tensioner was the remedy?

[dayasingh]

Originally Posted by ard

Im not sure about the chain 'slipping'. Could be slapping?

Anyway, for the ATC700, found this:
BMW X5 E70 O.E.M. S-Tec ATC700 Transfer box chain , 2006 >2010 models

Thanks for the information, the TC chain is very tight with very little wiggle room, I think if it get loose enough to start slapping, it probably will destroy the TC aluminum body in short order.

[ard]

Originally Posted by dayasingh

Thanks for the information, the TC chain is very tight with very little wiggle room, I think if it get loose enough to start slapping, it probably will destroy the TC aluminum body in short order.

So how does the chain 'slip'?

[dayasingh]

OK, my hypothesis is that the chain incrementally undergoes plastic deformation under load increasing in length and at certain point the elastic deformation plus the permanent deformation is enough for the chain to stretch over the gear teeth one tooth at a time as the torque is increased under throttle. A an instrumented test to record the type of vibration being generated can easily determine if there is a chain slip or just a loose chain slapping in the case.

[heatmizr]

No way. If it wears enough to jump a tooth it would continue worsening and would quickly deteriorate to the point of destruction in short order.