Gear box damage

[ejw]

Evening all

Having got a half decent set up on my 3.0 last night (with a lot of help) my tlr laydown gearbox decided to implode just before my final making a hideous grinding sound. Stripped it down today and found a lot of dust sized metal shavings and the gear the pinion attaches to ( don't know official term) has worn really badly as per attaches pics. Anyone have any idea why this might have happened? Everything seems to be seated properly and don't want to just buy a new gear and end up in same boat in a few weeks!

Any suggestions welcome as I'm not sure what to look for.

[johnboy]

What the state of the idler gear and diff gear? The bearings in the gearbox check them.

[ejw]

Apart from being cover in shavings and the teeth being more worn on one side than the other they seem ok, bearings are all fine, wondering if I have left something out when I built it, this is goin to sound like a silly question but are you supposed to grease everything?

[johnboy]

I would replace all the gear is any slight damage. I used a little grease on the gears. Did you tighten the screws up evenly and check for any tight spots before running. But you had some runs before hand so next question how much use had the layshaft gear your first pic had before using in the new gearbox

[ejw]

Yes everything tightened evenly, brand new with kit, only done 4-5 meetings. Just noticed in manual it says use black grease on lay shaft gear so will do that for a start and will def replace all gears, would just be nice to find a definitive issue in case it happens again.

[No. 46]

Thats definitely because there was no grease on the gears. You only need a little and it will keep them good for ages

[ejw]

It has never sounded the smoothest to be honest so definatley going to grease it up a bit when the replacement gears go in. Good to hear it's probably just a grease issue. Thank you both for the help

[danielc3009]

I'd say it's excessive wear due to running the gears dry. The layshaft gear is alunimiun which is a soft metal and will wear quickly without grease which is why I don't use aluminium pinions. I don't know what the idler is made from but is probably aluminium aswell.

I always grease the gears in the gearbox with black grease and never had a layshaft wear out. I've heard some people use shock oil instead, but don't know why.

[fletcher]

It's simply just because there was no grease in the gearbox. 2 metal gears together, dry, will cause this to happen. I just usually put a few dabs of black grease in mine whenever I have to strip it down for a diff change or what not. It's messy but after 6 months I'm still on the same internal gears from when I got the car on release date.

[Darren Boyle]

Elliott, trying greasing the gears with a good covering if clear diff lube and add a few drops of bearing oil to thin the grease slightly and that will work wonders and last ages

[ejw]

Cheers Darren, will be in for the layshaft and idler gear on Monday then i will rebuild it (properly this time).

[Big E]

What ever you do don't listen to Darren

You need black diff grease, clear diff grease is designed to increase friction which will wipe the gears out just as fast as no grease. Just a bit of black grease will be fine and like the others say jujutsu a little extra on occasionally when rebuilding.

E

[Darren Boyle]

Lol.... that advice came from you E years ago in the days of Royal Oil lol

Has worked ever since in all ours cars with no failures ever.....