Automatic Gearbox Filter, 2001 Volvo S40

[VolvoSieg]

I have a 2001 Volvo S40 with an automatic gearbox. I drove a distance of 1600 km down to Cape Town for a holiday. Within the first 10 minutes after I reached my destination, the gears suddenly started slipping. Suddenly when I put it in drive or reverse for that matter, there were no gears. Eventually I got 1st gear when I put it in D but it stayed in 1st and refused to switch to 2nd. On the dash there was an arrow flickering the whole time. I took it to a garage close by. They mentioned it often happens when the gearbox is overheated. They found the gearbox fluid to be very dirty. They drained the fluid, cleaned the gearbox and refilled it with new oil/fluid. When they finished everything seemed fine. I drove around for a few kilometres without any problems, but suddenly the same thing happened. I was advised to buy a new gearbox and they are searching now for a good 2nd hand one for me.

However, before I go that expensive route, I want to be certain that the old one is totally defective. I spoke to a mechanic who claims to know a lot about gearboxes. He mentioned that there is a filter in the sump of the gearbox and that filter could be the problem. He mentioned that it will serve no purpose to replace the fluid if the filter is not cleaned/replaced and that if the filter is dirty, there is not sufficient pressure to shift the gears. I was not charged for a new filter, therefore I know the filter (if there is one) was not replaced.

I would like to know if this gearbox indeed has such a filter, and if that could be the cause of my problem. Should I first try that before I replace the gearbox or is the gearbox totally damaged and should be replaced?

[jimmy57]

That gearbox has a strainer, not really a filter, and it is only accessible by removing and disassembling the transmission.

The fault codes should be read out and no assumptions made that the trans lamps was flashing for an overheat. It would be a shame to replace the who whole gearbox due to a failed sensor or wiring fault.

[VolvoSieg]

Thanks Jimmy. I appreciate your response. I'll convey this to the mechanic and have them remove and disassemble the transmission. However, this strainer you are referring to - is it a part that can be replaced or just cleaned?