We drove through deep water. All was ok for the next 700km's then the speedo stopped, causing over-revving (auto transmission).
Mechanic checked the electrics under the front of the car then said the problem is mostly likely the transducer. Can we fix this ourselves easily and cheaply?

Any advice would be greatly appreciated from this gal

Yep. Easy fix.

Go visit a wreckers and pinch one from under another car... Or maybe one from ebay.

They are bolted into the back of the trans, on the upper half of the drivers side extension housing. Will need an 8mm socket/spanner to remove. Then just unplug from the loom.

Swap the speedo gear over if they are different colours and refit the same as removal.

They only go in one way and fit one way, so its pretty foolproof.

I'm pretty sure they are the same from XF onwards... Or definitely EA onwards.

Yeah easy as.

The transducer is on the top R/H side of the transmission extension housing. I pretty sure its just held on by 1 bolt holding a clip. Take the bolt out and it will just slide out.

I fairly sure the new one will not have the speedo drive cog on it. You will need to take it of the old one.

If you want a brand new one I have one available for $50.

I bought it to try and fix a hunting issue but it didnt work.

Thanks so very much for your quick replies Sounds easy.

@ Dansedgli, thanks for the offer but we were able to source a brand new one in town today.