Hi I have renovated differential all parts was replaced. I think that works well but still I have heard some voice between speed 80-90 km/h. Like before renovation. The voice is lower but still I hear it.

 

Are you talking about gear whine?
What is your gear ratio before and after?
What brand parts did you use?
How did the pattern look when the hears were setup.

 

That's a pretty common speed for gear noise. If these were new gears then I would suspect that they were not set up correctly or they were not high quality gears. If they are good used gears then I would say that the pinion depth or backlash, or both were changed when the rear end was put back together.

 

MIDIAS

Yes I told about gear whine.

Ratio was changed from 2.73 to 3.23
Parts form summitracing

DELUXE KIT 7.5 GM RAT-3001K
RING $ PINION SET RMG-4900441
TRUE-TRAC 7.5 GM 3.23 DTL-911A319
Centric 414.64000

 

Richmond has a reputation for making noise in this range, but sometimes it's just the way that the gears are set up. Did you do the set up yourself or did someone else do it?