Gearbox Oil, knocking noises and metal shards?

[RyleyMA61]

Okie Dokie.

On the 3 hour drive home from a Winton track day, I noticed my gearbox had began to develop some odd noises:

* It was a lot noiser in 5th gear- metallic whirring and when under load would clack/knock a little bit
* When taking off from a standing start, (just normally, and in any gear) it will make a knocking/clapping noise, which increases with engine speed, and then goes away. it is only present when the the car is getting off the line and to about 10-15km/h. Sometimes I have heard a little knock when putting the car under load when driving in 2nd and 3rd gear also.

Now, I had it checked out and it was a suspected chipped gear or bearing/input shaft or something.

Anyway, I decided on the following action:

Drain gearbox Oil:

a) If there are metal shards, get another W58.
b) If there isn't, fill it will redline shockproof, and see if it fixes the problem.

Thing is, I drained the oil tonight and the oil itself was pretty good. A few little sparkly bits (like glitter, but very small) in the bottom of the container.

However the drain plug had a few splinter-sized bits stuck to it, and there was a thick metallic sludge on there (like metallic paint really)

NOW, my question is:

Is this amount of shit in the oil normal?
Should I put the redline stuff in, or get a new gearbox?
Does anyone else have any suggestions as to what the noise could be?
Any other ideas?

Thanks heaps for the help guys, appreciated.

EDIT: Car is MA61 w/ 7MGTE. Didn't really flog the gbox at the track. Has a truetrac but original crown pinion so the car rocks and clunks in the rear end too.

Could even be driveshaft or uni joint related???

[Crazyracer]

If the gearbox does have a problem, its probably too late to put better quality oil in it. If the oil looks OK I would probably put it back in until you find the problem.

Check you tail shaft and any bearings if it has a 2 piece tailshaft, diff bearings + crown wheel and pinion, wheel bearings and any C/V or uni joints for play.

If the gearbox does turn out to be the problem, its unlikely better oil will fix it. Get a new one or get the box fixed. Don't waste money on expensive oil to use in a box thats stuffed.

[IN 05 NT]

if you can feel the knocking noise thru the gear selector, you can be almost gaurantted its the box.....

splinter sized shards on the magnet...is bigger than usual....if you flog your box quite a bit, the oil will be metalic, and the magnet covered in the metalic sludge u already mentioned,

give the box n oil change, THICK oil, see what happens,

blake

[RyleyMA61]

alright thanks. i don't really flog the box, but it is 290,000mhs old and has a fair bit more torque going through it than it's meant to...

so despite the shards i should try something thicker? not try the redline shit though???

thanks blake

[IN 05 NT]

jjust get the thickest box oil you can get, theres alos additive stuff aswell you can try,

oil will cost $50, and may make it better, for a short time,

or $400 for another 57/58

in the end, it still a worn box, but hey you may postpone it for a while,

[Dazza]

Thicker oil will make it harder to change gears without crunching them. I would not go any thicker than an 80W oil. Some gearboxes run a sealed bearing on the front shaft so if it fails it will not contaminate the oil. I would pull the box out and put a new set of bearings in it before it strips a gear.

[IN 05 NT]

basic standard box oil is 80w, yeah thick oil will make it a slower change, but the idea is to make it last longer,

the additive i was talking about above is a small tube, 500ml or so and is something like a 120w-130w

if you want a quick easy gear change, use auto box oil,

blake

[Starfire]

The small shards and some minor glitter in the oil are pretty normal for an older box.

If a box is broken you tend to know about it (if all the gears work ok then its unlikely youve broken it).

As mentioned it's more likely to be a tailshaft or diff problem.

A broken gearbox mount can cause it to knock around during acceleration too.

[RyleyMA61]

ah thanks man. yeah the car still drives fine... 5th is a lot noiser than it used to be, and the knock/rattle on takeoff, but the car still shifts and boosts fine...

ill definately check the driveshaft and diff. the diff was noisy and clunky anyway, as the old crown and pinions are still and and a bit fucked... ill get it sussed out

thanks for that. this is all helpful, thanks