Transmission whine
 

I have a 5 spd man and 4.0. The trans whines in every gear except 4th. Any ideas?

Welcome to the forum


In a 5 speed Overdrive transmission 4th is 1:1 ratio so doesn't use the counter shaft, problem will be input gear(drives the counter shaft) or the counter shaft bearings most likely.

In a manual the gears are always meshed and spinning, but there is no load on them unless engaged to the output shaft.
The Dog gears are what engages each "gear" and what you would hear grinding on a mis-shift, not the actual "gear"

In 4th "gear" the input and output shafts are coupled together so it really isn't a "gear" in that respect because there is no ratio change, input shaft is spinning at engine RPMs, say 1,500rpms, and then output shaft/drive line is also spinning at 1,500rpm, 1:1 ratio
So counter shaft is not being used and has no load

Google: how manual transmissions work

Some good animations out there

You will need a rebuild to fix it