Bongo Fury

So we got our dear Bongo back from the garage with a "new" camshaft, head gasket, belt, etc. Changed a suspension arm 2 weeks later for the Mot and everything was fine.. Until it started acting weird with the gearbox.
The engine revs for no reason and seems to go up and down between gears a bit randomly. It struggles to go above 40 but even after at 60 it tends to happen as well.
We check the transmission fluid today and its brownish (maroon) which doesn't seem to be a great sign. I'll bring it to the garage tomorrow but I wanted to aks if you had any advice before that.
Can it be linked to the transmission fluid or is it something else completely and we're doomed?

Thanks for reading.

The gear box on my bongo started being "notchy". I suspected that the transmission fluid might be the issue. My mechanic asked me to get eighty (that's right eighty) Litres of transmission fluid and the set about replacing the same. He removed the sump and the connected the filter (after it had been cleaned and in effect had the transmission oil pump suck the clean oil through.

It was heartbreaking to see the cherry red stuff coming out (it ain't cheep) but once he was satisfied all the system was flushed out with the good stuff it was reassembled and the difference was absolutely brilliant. £80 quid for the fluid and one hour of mechanic time sorted the transmission. I believe that changing the transmission oil will certainly improve things. Biting the bullet as I did meant the whole of the oil was replaced. Just draining and replacing that drained still leaves about one third old oil in the system.

Once done my mechanic said it's good for another 250 thousand kilometers now.
Ian G

fatcatlawyer wrote: Sun Apr 07, 2019 8:23 pm The gear box on my bongo started being "notchy". I suspected that the transmission fluid might be the issue. My mechanic asked me to get eighty (that's right eighty) Litres of transmission fluid and the set about replacing the same. He removed the sump and the connected the filter (after it had been cleaned and in effect had the transmission oil pump suck the clean oil through.

It was heartbreaking to see the cherry red stuff coming out (it ain't cheep) but once he was satisfied all the system was flushed out with the good stuff it was reassembled and the difference was absolutely brilliant. £80 quid for the fluid and one hour of mechanic time sorted the transmission. I believe that changing the transmission oil will certainly improve things. Biting the bullet as I did meant the whole of the oil was replaced. Just draining and replacing that drained still leaves about one third old oil in the system.

Once done my mechanic said it's good for another 250 thousand kilometers now.
Ian G

Where did you get 80litres of transmission fluid for £80.00 quid??

You spoke too soon on your other post!

Given a garage has had the Bongo (?) for so much work and this fault was not present beforehand I think they should put this fault right at their expense/time. Diagnosing GB issues on the net is pretty impossible but I had an issue akin to the one you describe with the box mis-shifting due to revs rising in and out of 'OD' etc, a quick adjustment of the TPS sorted it. These threads may help, top one is the best:

viewtopic.php?f=3&t=18421

https://www.igmaynard.co.uk/bongo/forum ... =3&t=10162

viewtopic.php?f=3&t=66257

Sounds like its overdue a fluid change anyway and as Flanners has said TPS could be the culprit so worth getting that checked out. Good luck getting it sorted and keep us posted.

Thanks for the feedback.
It is now with the garage. I'll see what he says. Thanks for the TPS direction. That's another thing to check before worrying too much about replacing the whole thing.
Hopefully it 's just one of those two!
I'll keep you updated as soon as I know more.

I've got an update form the garage. He didn't have much time to dig deep as he's going away for a week but he took some of the transmission fluid away (suspecting something is leaking into it) and had a look at a few vacuum pipes that he replaced because they were in bad shape, thinking that they might send the wrong info to the sensor.

I'll drive a bit tomorrow if it changed anything.

Sounds like an engine issue to me.

@Alacrity: what do you mean?

I drove the Bongo a bit yesterday and the problem is still there. Maybe not as prominent (less random switching between gears) but quite a bit of revving because you need to push further to go to the next gear.

It would be worthwhile having the valve and pump timing checked , also replace and clean ALL filters.

Sorry for the long delay in answering. My garage has been all around but can't seem to be able to fix the problem. His conclusion is that it sadly comes really from the gearbox itself.

He gave me a number of a company in Bristol who specialises in auto gearbox but I thought I'd send an email to Bongo Spares first to see what the gearbox would cost first, without fitting.

This firm in Gloucester will service Bongo gearboxes: www.autotransgloucester.co.uk