Good day, after replacing the clutch and two mass flywheels, there are some problems left when the cold car gearbox works perfectly, well, it seems to me that when it warms up, strange work, sometimes dulls between the gears, sometimes in traffic jams, I throw off on N there are light shocks, strange work between the first second and third, if you drive on these gears, start gas if there are any pushing, as if pushing from behind who, and the same way if you give gas, pushing and everything works perfectly, sometimes there is a vibration on the body, sometimes you brake in front of the traffic light, and you feel that you are pushed by the gear, and another question, can you somehow check the differential without opening? To all the world