Hi.. I have a 1999 S80 ... Last year a transmission shop told me my tranny was shot and needed to be rebuilt. I took tech's advice and decided to keep driving it.
Its still going strong but sometimes before going on a trip I still worry about it.

Does anyone know what RPM the engine should be running at, at agiven speed?
My S80 does the following:

1800 RPM @ 90 Kmh ( 55 Mph)
2200 RPM @ 100 Kmh (62 Mph)
2400 RPM @ 120 Kmh ( 75 Mph)
2700 RPM @ 140 Kmh (88 Mph)

There doesnt appear to be any slippage or shudder but the thought of tranny failure has been in the back of my mind since the shop told me about it.

 

What reason was giving for needing a rebuild? DTC's?

 

had car in for transmission oil & filter change,tech found some small pieces of clutch material in bottom of pan

 

For these transmissions that is relatively normal. Most oil and lube places don't know what the hell they are talking about anyway.

If you are concerned which I wouldn't be take it to a dealership for a tranny flush. They will take a look at it for you.

If your transmission was bad, you would know. Trust me.