Transmission issue

[cristian]

Hi there, my name is Cris and I have an Olds 88 LSS, 1995, that recently has been serviced for a intake manifold and a drive belt tensioner. A new problem seems to showed up. The car has 116,000 miles and since 85,000 miles , when I got it, I never serviced transmission. few days ago I noticed that while the car shifts through gears normally, as the speed reaches 40-45 mph a grunt noise is heard. Going uphill I experienced vibration and low response from transmission. This was observed in 3rd gear and also in overdrive. Checked the transmission fluid- is clear (red), no smell. There is no warning light, and above 50 mph the car/transmission works fine. It is just in this range where I can hear the grunt noise: 40-45 miles. Can somebody help me with an advice? Is it a transmission problem or a solenoid?

Thank you,
Cris


Came back one day later with new info. Got into an AAMCO shop. The mechanic drove the car for 15 min and concluded that is the torque convertor that needs to be replaced, about 300$. In addition he suggests that I should rebuild the whole tranny since they believe that the cause could be internally(seal, wear and tear condition that generated this malfunctioning convertor). For this they want about 1,800$. What do you think? Anybody? Help....