auto gearbox oil leak

[ant n jodie]

hi bongoers having recently just brought a 2.5td 4x4 bongo , upon first checking all fluid levels , discovered oil tray full of oil and gearbox oil empty so have filled and there seems to be a leek on floor after driving , carnt really see where coming from as quite dirty under there but cud this just be a gasket issue or somethink more severe , next stop is to steam clean and try too find leak. any further ideas anyone ?

[Northern Bongolow]

read this.
http://www.igmaynard.co.uk/bongo/forum/ ... =3&t=58378.

heres the pipework drawing.

http://lushprojects.com/bongopartsmk2/c ... mgno=.html

[Bob]

Welcome aboard.

Let's hope you're sorted soon.

[ant n jodie]

wow that's a quick response thank you will checks pipes out .

[corrour]

Just had the same problem.

Replaced both pipes from gearbox to radiator bottom with 10 bar high temp hydraulic rubber pipe from a local supplier.

Just done 2000 miles no leaks or problems

Far easier to thread and clipped to existing pipes for security.

[corrour]

This is what I used.. if it helps

[Northern Bongolow]

[ant n jodie]

Hi guys, well i've just visited my mechanic mate who put our bongo up on his ramp to have a look at the gear box, and now the gear box oil has been topped up, its not just leaking, its pissing out, about 1.5litres since friday
He is sure it is leaking from the front pump seal on the gear box. This is by the torque converter and input.
I can't see anything matching that listed on the parts list on here and am desperate to get it done so we can take him to cornwall in a few weeks.
Does anyone know where i can get hold of such part???
ANy help or advice would be great, Thanks in advance

[Northern Bongolow]

does this help.

http://lushprojects.com/bongopartsmk2/c ... mgno=.html.

sounds like the box needs to come out to see whats going on and where the leak is.


here's the list of seals and gaskets.

http://lushprojects.com/bongopartsmk2/c ... mgno=.html

[Alacrity]

If it is leaking from the bell housing then it will almost certainly be the converter seal, although I have seen leaks from other places in there (loose bolts etc.) Box has to come out, converter checked to see if the neck is worn or damaged, if so it will need changing. The pump should be removed, you maybe lucky by just changing the seal but probably not. The front seal (assuming that is where the leak is) usually leaks because a) the converter neck is damaged if so then b) the pump bush may well be damaged or the pump bush may just be worn or c) the seal has gone hard & worn due to high trans temps (bad news as all the dozens of internal 'rubbers' will be the same) d) all 3. Either way it is a lot of work to remove & refit the tranny so we will only do a seal & bush here - not just a seal.

The oil pump in the front of the trans is capable of pressure of up to 4 -500 psi, this pressure is sealed in by the pump bush in which the converter runs. There is a cavity into which any that gets through the 0.003"(ish) gap drains into then back into the gearbox, with the seal just taking care of the splashed oil. A worn bush & or damaged converter neck lets far too much oil through so it cannot drain away fast enough & the seal gets pressurised & leaks. A new seal only will continue to leak as the cause has not been remedied.

[mikeonb4c]

If it is leaking from the bell housing then it will almost certainly be the converter seal, although I have seen leaks from other places in there (loose bolts etc.) Box has to come out, converter checked to see if the neck is worn or damaged, if so it will need changing. The pump should be removed, you maybe lucky by just changing the seal but probably not. The front seal (assuming that is where the leak is) usually leaks because a) the converter neck is damaged if so then b) the pump bush may well be damaged or the pump bush may just be worn or c) the seal has gone hard & worn due to high trans temps (bad news as all the dozens of internal 'rubbers' will be the same) d) all 3. Either way it is a lot of work to remove & refit the tranny so we will only do a seal & bush here - not just a seal.

The oil pump in the front of the trans is capable of pressure of up to 4 -500 psi, this pressure is sealed in by the pump bush in which the converter runs. There is a cavity into which any that gets through the 0.003"(ish) gap drains into then back into the gearbox, with the seal just taking care of the splashed oil. A worn bush & or damaged converter neck lets far too much oil through so it cannot drain away fast enough & the seal gets pressurised & leaks. A new seal only will continue to leak as the cause has not been remedied.

...and you'll not get better advice than that, even if its not great news. I'm pm'ing with Geoff at the moment over a mysterious slight singing sound that i'm pretty sure is coming from my autobox. It's working fine but i'm bracing myself for a possible bill.

[ant n jodie]

Replacement box fitted and back on the road , thanks for all advice

[spen68]

Folks.. I'm facing a similar problem. Auto box on a '95 AWD Diesel. Ground to a halt and RAC man topped up the oil and it came straight back out again. It's up on the ramps at my local garage now and he says it looks like the seal between the Torque Converter and the Box. He's not sure whether replacing the seal will be enough if there's something else involved and maybe I should replace the box. A couple of questions:
1) What are the chances that just changing the seal will be enough? Any tell tell signs I should ask him to look for?
2) If I need a new box, where's the best place to source one and which boxes will fit (model years, will a box from a different model fit?) There's one here on eBay but it's from a 99 model:

http://www.ebay.co.uk/itm/Maza-Bongo-Fr ... 2a32e1dde9

She's an expensive thing to keep on the road my Bongo but I still love her! She had a replacement engine a few years back

Thanks in advance for any help/advice.

[spen68]

Just a quick update on this.. Gearbox number is BM711 (another number stamped next to it is 5766428) if that helps.

Guy at the Garage in two minds - try changing the seal and see if that fixes it. If it does great. If not then I'm in for another lot of labour plus the cost of the replacement box 2nd time around.

The other dilemma, if I do change the box with a used one from a breaker, how do I know it won't have the same issue? So far used boxes seem to be around £250-£300. Recon boxes seem to be a lot of money - £1250ish!

Feedback and suggestions gratefully received

[mikeWalsall]

Maybe take heed of .. Alacrity .. recommendation a couple of posts up ^^^ ..??

If it is leaking from the bell housing then it will almost certainly be the converter seal, although I have seen leaks from other places in there (loose bolts etc.) Box has to come out, converter checked to see if the neck is worn or damaged, if so it will need changing. The pump should be removed, you maybe lucky by just changing the seal but probably not. The front seal (assuming that is where the leak is) usually leaks because a) the converter neck is damaged if so then b) the pump bush may well be damaged or the pump bush may just be worn or c) the seal has gone hard & worn due to high trans temps (bad news as all the dozens of internal 'rubbers' will be the same) d) all 3. Either way it is a lot of work to remove & refit the tranny so we will only do a seal & bush here - not just a seal.

The oil pump in the front of the trans is capable of pressure of up to 4 -500 psi, this pressure is sealed in by the pump bush in which the converter runs. There is a cavity into which any that gets through the 0.003"(ish) gap drains into then back into the gearbox, with the seal just taking care of the splashed oil. A worn bush & or damaged converter neck lets far too much oil through so it cannot drain away fast enough & the seal gets pressurised & leaks. A new seal only will continue to leak as the cause has not been remedied.