Really really loud 5th gear on dogleg tranny

[ServeEm]

Had this problem ever since I bought my 510 so I don't know what might have caused this issue originally. I thought maybe it was just low on gear oil so I drained and filled the tranny. It runs fine in all the other gears but it gets really loud when I shift to 5th gear. I can run her in 5th gear and there isn't any other signs of mechanical issues. The tranny just sounds really eff'n loud so it's concerning. Has anyone else had this issue?

[rpowell25]

I have a 280ZX 5spd with the same issue and in my case I am certain it is bearings. Time to crack it open and do a rebuild.

 

Robert Powell

[MAG58]

I'm not sure on the A series trans, but the Z/ZX trans it almost always signals a bad bearing, and noise in 5th only is usually a sign of the rear layshaft bearing flying the coup.

[datzenmike]

The 5th gear is at the front of the tranny. Actually 4th is right at the front but it isn't really a gear, it's just straight through no gearing. All other gears other than forth, produce a sideways thrust between the main and counter shaft trying to force them apart. This force has to be absorbed by the counter shaft bearings, front and back. If one of these bearings is damaged, usually the front one, it will usually be growly in all but forth. This is odd that it's only 5th.

 

BTW... always down shift to 4th for passing, hill climbing or towing on the highway. 5th is for steady highway cruise speed. Down shifting will reduce the stress on the counter bearings and prolong their life. Always change the oil every 30K.

[ServeEm]

Thanks everyone for you input, bummer that it sounds like a bad bearing. Yea there isn't any loud noise on the other gears, just fifth.