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Transplanted the grey today with the low mile grey I got. Good news is "new"grey isn't leaking oil.
Bad news is that there seems to be a heap of oil leaking out the front of the crash low box. Please tell me there's a easy to replace front oil seal on the box...??

Hmmm...what makes you think it is the gearbox and not the notorious rear-main seal on your new grey?

Hate to say it, but that's what I would be looking at, especially if the motor has been sitting for a while and it has had time to dry out.

If it is the rear main, might be an idea to pull the motor and put new gaskets, seals & welsh plugs in.

Cheap job, and could save tears in the future.

I saw the new grey running for 10 minutes and not a drop of oil anywhere. It was bolted up to a different box. Bolt it up to mine fill the motor with oil no leaks for a full day, then put a litre of oil into the box and it pisses out. Must be the box

Certainly sounds like the gearbox doesn't it.

I'd have to suggest that you PM Harv. He's a bit of a guru and I think he has recently been delving into how to overhaul the gearboxes.

Mmmm... MeFB is right - more likely to be a rear main. If you're confident it's not (lots of wiping down motor/box with rags, then back-tracking oil flow), then the stuff below may be useful.

From what I understand (and happy to hear otherwise, plenty of guys on the forum have pulled apart more boxes than me), the rear of the gearbox has a seal that seals the output shaft against the extension housing. This one is a bit easier to fix (and could be done with the box in the car).

If it's a leak from the front of the box, things are more difficult as there is no seal in the front of the box. The front of the box has an oil slinger ring and bearing. The oil flung off the slinger returns to the box through a drain hole in the clutch gear retainer. Oil piddling from the front of the box could be:
a) a missing or loose oil flinger,
b) massively sloppy front bearing clearances,
c) a misalligned or blocked clutch gear retainer oil hole.
No way to get at this one without pulling the box out.

Again, I could be wrong on this - happy to hear other views.

Dumb-ass question - you're not overfilling the box are you (admittedly hard to do)? It should be 1/2" below the filler hole (kinda hard to overfill, though it worries me a little when you said you were adding an extra litre of oil - there is only 943mL in a full box).

Cheers,
Harv (apprentice gearbox fiddler).

Thanks guys. I'll try another box in it. As I said when there was no oil in the box I had no leaks. Added oil ( not quite a litre) and it pisses out. Saw the motor bolted to another box running for 10 minutes and not a drop. It all points to my box

I hate pulling gearboxes - some things to try before you swap:

a) dip the box (use a bent wire or paperclip) and dip the engine (with the dipstick). Let it piddle for a while, then dip both again and see which one has lost the oil.
b) pull up some of the fresh oil, and compare it to both gearbox oil and engine oil - gearbox oil is thicker and stinkier (GMH technical term ).
c) make sure the gearbox bottom cover (sump), selector seals or rear seal are not the source of oil (it often blows around in funny directions with the wind under the car).

Cheers,
Harv.

The oil is running out of the hole in the bell housing. No where else. Surely it has to be the box???????:(

I'm still putting my money on rear main seal. Not meaning to sound negative, but it seems more likely that you refilling the gearbox before the leak started is just coincidence.

Only one way to find out...

MeFB wrote:I'm still putting my money on rear main seal. Not meaning to sound negative, but it seems more likely that you refilling the gearbox before the leak started is just coincidence.

Only one way to find out...

Nah, my money's on the gearbox especially considering it only started after he filled the gearbox. Take a real good sniff of the oil on the floor. You'll sure as hell know if it's gear oil!

Time to get down and get sniffing

Go on - ya know you want to.

Stick your finger in and sniff it You'll know if it's cum from a 'box

He He He He He,

Its a definate finger sniffing excercise

The smell is one of a kind !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Get the gearbox oil and have a whiff, then insert the finger get it moist and sniff away, very successful if you know what it smells like


Regards Greg.

Just curious, was it leaking from the rear-main, gearbox or something sneaky like the side-plate