1993 Jeep Wrangler Transmission whine while in fifth gear

Make sure the lubricant used in the transmission meets or exceeds API GL-5. You can also try to verify that it is the transmission for sure and not other drivetrain components or harmonic vibrations if the rear axle is lifted so the rear wheels are allowed to rotate freely. Put the car in 5th gear and check. USE CAUTION, MAKE SURE THE CAR IS SECURE IF YOU PLAN ON GETTING UNDERNEATH WHILE IT IS RUNNING.

It whines only while in fifth gear. The whining gets higher as the rpm increases. When I push in the cluth/ride it in neutral with the shift lever still in fifth it stops whining. But when I let the clutch out and fifth is engaged it continues to whine. I am using 75-90 gear lube. I had to replace the old tansmission becuase the fifth gear was just completely shot in it and would not even drive in it. Anything else?

I have to tell you I am not a fan of the puegot tranny. Good to press the clutch while at road speed this puts pressure on the t.O. Bearing. I have still seen them sing like this in only one gear tho so that may be your problem. Also with the ax-5 I have seen the shift forks and shift collars get sloppy and cause a humming or whining. Hope this helps. Curt