The vehicle is a 2000 XC 2.4L AWD with 129k miles. I recently invested in a new ETM and also new cam seals, timing belt, etc. I recently noticed that the transmission has a loud whine when in R or D at an idle stop. It is worst on cold start up and gets less obvious at normal temp but does not go away completely.I thought it may have been the angle gear for the AWD but that doesn't turn when sitting still; I also serviced that with synthetic gear oil- that old oil was really really really dirty. So... what makes a loud noise as it wear in the transmission? how soon should I sell??? Thanks for all the help from the gurus.

 

are you sure its the transmission? Have you changed the tranny fluid - or just the angle gear's oil? If not, consider dropping the pan and do a magnet check for any debris, then refill to the correct level following the proper cold/hot check produre.

 

There is a gear pump in the front of the transmission which powers all the hydraulics, and that is something that can whine. It sounds like a power steering pump whining, so those can be hard to distinguish. It is always turning, no matter what gear you're in, at crankshaft speed.

 

Does it turn in Park as well?

 

If it is a whine, it may be due to the transmission oil pump running dry. I would have the transmission fluid level checked ASAp as running with no little transmission fluid can burn the trans quick.

 

Trans fluid is clean and full

 

The oil pump in the transmission turns in park with the engine running. Any gear, as long as the engine is running.