Auto Gearbox Problems

[Fluffibonce]

Hoping someone can guide me here I think our gearbox has gone kaput but help and guidance would be appreciated!

Ours is a 1998 4 x 4 auto Bongo with around 70,000 miles on the clock. Recently the car appeared to be slipping when driven under pressure such as up a hill, then last week when drivng throught our local town a significant clunk was heard and the car wouldn't drive at all at first then with a futher thud it found a gear and off we went very noisily. This noise continues all the time although it seems to reduce when the hold button is clicked on. Moving off forward or reverse was a process of revving, then no initial traction, a thud and off we go (noisily). I've taken Ali Bongo to our local garage who have always done a good job maintaining her and they are diagnosing a kaput gearbox. I've started the search for a used unit (BM715 unit) but any thougths before I proceed further would be appreciated

Regards

GF

[mikeonb4c]

Hoping someone can guide me here I think our gearbox has gone kaput but help and guidance would be appreciated!

Ours is a 1998 4 x 4 auto Bongo with around 70,000 miles on the clock. Recently the car appeared to be slipping when driven under pressure such as up a hill, then last week when drivng throught our local town a significant clunk was heard and the car wouldn't drive at all at first then with a futher thud it found a gear and off we went very noisily. This noise continues all the time although it seems to reduce when the hold button is clicked on. Moving off forward or reverse was a process of revving, then no initial traction, a thud and off we go (noisily). I've taken Ali Bongo to our local garage who have always done a good job maintaining her and they are diagnosing a kaput gearbox. I've started the search for a used unit (BM715 unit) but any thougths before I proceed further would be appreciated

Regards

GF

If he doesn't read this and post, try PMing BF member 'Alacrity' as he is a (professional) guru where autoboxes are concerned. Good luck and hope its not too expensive.

[Alacrity]

It sounds as if the geartrain has failed within the transmission. I suspect it was putting metal debris into the oil which started sticking up the valvebody which may have caused the slipping you experienced. I'm afraid it is time to either find another transmission and torque converter (don't change the trans without the converter or there is every chance you will be back where you started in a short while)or get yours reconditioned. There is a very good transmission rebuilder in Glasgow, John Mackie Automatics 01417 784545. He is not the cheapest but he is one of the best around, with, like us, factory contracts to his name.

If you do get a 2nd hand unit make sure whoever fits it flushes the oil cooler out properly, or the replacement will end up contaminated & in trouble again.

Good luck.

[Fluffibonce]

Hi there thanks for the advice - funny enough i'd just found Mackie and their credentials look good! First stop will be a 2nd hand unit though methinks - thank you for the advice

[dandywarhol]

Seems to be a helluva lot of auto boxes failing in the last 12 months............

[Alacrity]

Is that since I joined up??

[dandywarhol]

Haha - I was thinking that as I typed it

[Fluffibonce]

After a visit to John Mackie anda quote for £2300 +VAT for reconditioning (not inc transfer box)!!! I am now on the look out for a second hand unit. Having checked, it is the BM715 type of box. I've checked with Bongobits and they have nothing at this time; so does anyone have any other ideas for a source of a good unit?

Best Wishes F

[You've Been Bongod]

pm sent

[Fluffibonce]

Well we are fixed and back on the road. it seems that the cause was a holed oil pipe to the autobox, this leaked and with no fluid, kaput no drive. So a thought, as the bongos get older and the salt on our roads rots our cars - check the pipes to your autobox..and more. when the repair was being made Ian who fixed the car spotted that a metal pipe for engine cooling was also rotted and was weeping coolant. Fortunately for us he changed the pipe and helped to avoid cylinder head failure.

Now, not being ubber mechanical i can't give precise names to these two pipes, but hopefully someone else can, because watching the site recently there have been a few autobox and engine failures - could this be a cause?

BW
F

[dunslair]

Glad to hear you are sorted..... thanks for follow up post with cause once diagnosed. Another one to watch out for in the future

[Alacrity]

a significant clunk was heard and the car wouldn't drive at all at first then with a futher thud it found a gear and off we went very noisily. This noise continues all the time although it seems to reduce when the hold button is clicked on. Moving off forward or reverse was a process of revving, then no initial traction, a thud and off we go (noisily).

I am very pleased you are sorted by just repairing an oil cooler pipe. But I am also very confused. If a transmission is running low on oil you can get a delayed engagement with a thump into whichever direction gear you have selected, that is normal under these conditions. However you said the transmission had also gone noisy?? Low oil will not cause the trans to be noisy.

A semi choked filter will cause the pump to scavenge & will make it start to whine, changing the oil & filter will stop this, but if the filter was choked enough to cause the pump to scavenge then there is some serious damage somewhere. It is unlikely the trans will last a long time under these circumstances.

As I said, very confused!