Hi all

I'm hoping that someone on the forum might be able to help with my Volvo gearbox problem......

Bought a 2000 Volvo S80 2.4t as a good tow car for transporting the Locost to speed hillclimbs. It was cheap and high ish
(150K) mileage so always going to be a bit of a gamble.

It has driven well for the month or so I have had it but recently has developed an annoying problem.
When in Drive and travelling down an incline on overrun the gearbox appears to disconnect the drive and the vehicle starts to freewheel and gather speed, much like a manual car would do if you knocked it into neutral. At the same time the engine revs drop to around 500-600 rpm compared to its normal 800-900 rpm idle.
Strangely when you approach a junction the opposite happens and the engine/car shudders and the revs drop as if the gearbox or torque converter has not disconnected the drive?

I have used a friends code reader to check for faults but am not sure if this would flag up faults with gearbox ecu?

Suggestions so far range from changing the fluid to scrapping it so any thoughts or suggestions welcome!!!

Steve

Replace fluid and filter is favorite, modern boxes are very sensitive to fluid levels it may just be a little low, slowing throws fluid to the front and it picks up drive maybe.

Sounds like low fluid level, not sure what transmission the S80 use but it wouldn't surprise me if it is the Jatco 5 speed which is notoriously fickle about fluid level and type.

Did some checking it seems to be a GM box

Thank you for the advice, I will check level and consider changing it.
Just to add...... It drives realy well when under acceleration or if there is some throttle on, in fact it goes like stink when flat
out, all gears change smoothly etc , its just this overrun freewheeling/junction problem that is worrying me!

I'll check fluid at weekend

Thanks

Steve