I just swapped out the half shafts on my 2000 neon. Now on the passenger side there is a terrible noise coming from the transmission. It gets louder and higher pitch the faster I go. I talked to a local mechanic who said the bearings in the trans are shot and I need a new one. Has anyone ever had a similar issue? Does anyone know if I can just replace these bearings where the shaft goes? Can I do it with the trans in the car?

 

Was the noise there before the shaft was swapped? If not, I would check to make sure the shaft is properly seated in the transaxle. If the replacement shaft was used it may be an issue with the shaft itself. Another possibility could be the wheel bearing on that side, was the Axel/hub nut tightened to the proper torque spec. (180 ft/lb)?
Worst case I think I would try another shaft before opening up the transaxle.

 

Do you have the proper amount of transmission fluid?

 

The noise was not there before the new half shaft was installed. It seems to be seated correctly and the wheel hub is good. The nut was also torqued to spec. The fluid was checked and the levels are good there as well.