BW auto oil puzzling leak.

[Gresley]

Hi chaps,

My Stag has a BW 65 auto box which works and does it's job beautifully, but has developed a severe oil leak. During normal driving it leaks a little (not much) but cruising at 3000 rpm (60mph) on the motorway it seems to pour out. A lot ends up on the nearside exhaust thus creating not inconsiderable smoke! I have looked for obvious things wrong such as the breather pipe being off, loose unions, split pipes/hoses and for obvious places where there is a leak etc but I can find nothing obvious. So frustrating!

Does anyone have any ideas please?

Thanks
Brian.

[Rubce]

Rip out the slush box and replace it with a MOD

Regards

Bruce

P.S. Only joshing

[Gresley]

One that doesn't leak preferably...!

Regards
Brian

[GDPR]

Come on Brian - join the 21st century and get a ZF...

Russ

[jbuckl]

If its only nearside, the obvious candidates are the selector switch & or selector spindle seals. (both are changeable in situ)
Spray with brake and parts cleaner to clean & dry off.
Run the car in drive, preferably securely jacked up & try to observe the origin of the leak (S!)
FWIW I had some pretty bad leaks from the ZF after it was first fitted.
So if you want to stay with a BW, its the same procedure no matter what the origin of the 'box.
The BW breather hose is also a candidate for leaks....the plastic outlet needs to be sealed to the box, and the pvc breather pipe often needs a fuel-pipe clip onto the outlet molding to stop it leaking too.
My BW was eventually leak free, but always worried it was empty(!).....had to change to ZF as the worn / noisey B.W.oil pumps are N.L.A.

[Gresley]

Hi Russ,

I think it may eventually go that way...! Although I think I am stuck in the 70s generally!

Brian.

[Gresley]

Hi jbuckl,

Many thanks for the tips. I have not had time to spray cleaner on yet but I did wipe it clean a couple of days ago. Running around it does not seem to have leaked so much, but I will have a long run and look at the spindle seals etc...

Thanks
Brian.

[StagManiac]

It is almost impossible to diagnose such a fault remotely. However, when I first got my Stag back in 1989, its BW35 (note - not BW65) leaked reasonably steadily from its tailshaft bearing oil seal. It sounds to me as though your 65 is doing something similar. That may be why the leak is faster when at higher speed because the transmission output shaft would be turning much faster than at low speed.

Your best bet would probably be to get the car to a transmission specialist for diagnosis and a repair quotation.

Paul