Recently the gears started to slip in third and above and come to think of it, on the motorway it would always try to change down, rev a lot and then change into the required gear.
Then it stopped going any higher than second gear - when attempting to go any higher the engine revs but will not select gear. I can drive around in S or L mode more easily than D, but I can still only use the first 2 gears at a top speed of 30 - 35 MPH at most.
We checked the oil level, which was just below the low mark and quite treacly / brown. We have changed the fluid, by sucking the oil out, dropping the sump and cleaning the filter. This is why we think the gear box may have an internal fault, because the magnet was covered in iron filings, which is normal we know - but more than we would have normally expected. Also whilst rinsing the gear box filter through there was brass flakes found.
After all this work there was no change. We have rang various Bongo garages and in their opinion we need a new box.
I understand that each box is coded to the Bongo (mine is BM714) but I haven't been able to find one with that code yet - I have found lots of BM710's
Why do I need to match the code? Is there anything that can be done in order to have a different coded gear box transplanted into my vehicle in order to make it work - i.e. the gearbox ECU or similar.......
Nobody seems to know or are prepared to give us the answer!
Thank you in advance
