Auto gearbox won't change up

[Gasy]

Ah yes is this the one we're the gear box was changed and the same prob occurred
Beyond me then mate other than it must be something controlling the gear box
Good luck not seen this lot beaten yet so keep plugging away
It will get sorted

[pongobongo]

That's the one.

Still the the same - it's making a sucking sound now when it slips (sounds a little like rain in the wheel arch). Identical to before.

Unsure if I should do a full atf flush/clean or bite the bullet and take to a specialist.

Any input is much appreciated.

[mikeWalsall]

Two boxes with the same problem ..

Seems like some thing on the van at fault .. giving the same problem to both boxes ..

Or are both boxes are part of the recall batch with dodgy internal solenoids ..

Why was the Bongo scrapped that No2 box came out of .. was an 'iffy' gearbox part of the decision to scarp it ..??

[pongobongo]

I know. It doesn't make sense does it.

And what makes it even more confusing is the problem is identical. Loss of power - then noise after a few weeks - only happens when warm (20 or so minutes into journey).

Totally at a loss here. If another box is put in and the issues occur again.... Well I won't be happy to say the least!!

It could easily be something on the van which is affecting/destroying the boxes - unsure what/where tho.

Upon inspection the ATF is dark dark brown - maybe worth a punt changing/flushing that first.

Thanks for raising the questions.

[rita]

Not saying that it is the problem but out of interest was the Torque Converter changed when you fitted the replacement second hand box from the scrapper.

[pongobongo]

Yep the torque converter was changed too - we actually thought it was that and not the gear box. But changed both anyway.

[mikeWalsall]

Must have been a lot of the old fluid still in the box / torque converter ..

Even in situ It's a very simple job to remove the sump and clean it / the magnet / filter .. the gasket it a thick rubbery one .. if you are care full it will 'go again' ..

Stupid why the Japanese did away with the torque converter drain bolts ..

With Borg Warner boxes there was a little 'window' at the very bottom of the bell housing .. you got the engine to BDC and undid the drain plug on the converter .. box and converter fluid drained out hassle free ..

[pongobongo]

Nah - the new gear box was installed (inc torque converter) and new fluid installed.

However, I supose the garage could have used fluid from the old box.

It is defo not the right colour. New box went in during feb.

How do I drain the torque converter?

[mikeWalsall]

Just a thought as I am not auto techy ..

If the problem generally occurs at the same time / speed/ engine temperature ... is it about the same time as the gearbox goes into 'lock up' ..??

My limited understanding is that when the fluid is warm and at a given road speed (I 'think' on the Bongo @ around 45 -50mph) a clutch engages locking the engine to the rear axle .. giving the engine / transmission a more efficient direct drive ..

[mikeWalsall]

The way most DIYers change the converters fluid is by either by draining the sump .. refilling with fresh fluid .. use the motor for a few days .. drain again .. re fill .. and carry on until the fluid looks a cherry red ..

Or .. box in 'P' .. remove the fluid (oil) cooler flow pipe from the gear box to the bottom of the radiator .. put a measured container (say a 2liter milk carton) under the end of the pipe .. some one starts the engine and fluid will pump out .. tell them to stop when (say) 1.5 - 2 liters of fluid as been pumped into the milk carton .. re fill the box with the same amount of new fluid ..

Keep repeating the start .. pump .. stop .. re fill .. until only new cherry red fluid is coming out of the oil cooler pipe ..

Re fit the pipe .. top up the box .. check fluid level with the box in 'P' with the engine running ..

[pongobongo]

Just a thought as I am not auto techy ..

If the problem generally occurs at the same time / speed/ engine temperature ... is it about the same time as the gearbox goes into 'lock up' ..??

My limited understanding is that when the fluid is warm and at a given road speed (I 'think' on the Bongo @ around 45 -50mph) a clutch engages locking the engine to the rear axle .. giving the engine / transmission a more efficient direct drive ..

Defo same time/tempreture - not speed tho. Going uphill mostly (although can recreate the slip by flooring it - but only when temp is up).

Thanks for the info re the flush. I'll do this asap - at least the AFT can be eliminated.

[Northern Bongolow]

just curious, does the cold start work ok or does it chug into life when the weather is really cold, and do the front radiator fans come on when the engine is really hot.

[pongobongo]

just curious, does the cold start work ok or does it chug into life when the weather is really cold, and do the front radiator fans come on when the engine is really hot.

When it's been left standing for a while it does chug into life (some white smoke when cold). Runs rough for 10secs or so. After that initial start - it starts perfectly the next time (unless left for a good few hrs).

To be honest, I haven't checked the fans. Are you thinking the atf could be boiling?

[mikeWalsall]

The engine fans are not continually on .. and they cool down the the 'water' in the radiator .. and have little to do with the AT fluid ..

Extra aftermarket fluid coolers are available .. but even towing a caravan the fluid usually stays cool enough not to cause issues..

[pongobongo]

Ok just an update...

Fans are working.

Sump off and fluid changed - old AT was Dark brown. (Didn't drain TQ - will do over next few days).

Temp of engine was still up - drove off and slipped straight away.

I'm guessing this rules the fluid out - and pointing towards something regulating the tempreture of engine/gear change or box & torque converter have had it.