What is the cause of gear failure?

[brianrogers]

What is the cause of gear failure and how to prevent and maintain the gear box? 

[GTSBoy]

Excessive torque is what chips teeth off of meshed gears. That can be a direct effect from simply giving it way more than it can handle, or it can be a cumulative thing where the shaft bearings cop a flogging over time and then allow the shafts to move apart and load the gear teeth incorrectly. It can also happen where the case can't take the torque loads, deforms and allows shit to move to new and unexpected positions wrt each other.

Hamfisted shifting is what strips teeth off of synchros.

[The Bogan]

My old boat with 700nm and drag radials would kill a box to quick.

It basically chewed the surface off the gears turning the gearboxs into a screaming banshee

[MrStabby]

On 6/4/2019 at 6:44 PM, mlr said:

My old boat with 700nm and drag radials would kill a box to quick.

It basically chewed the surface off the gears turning the gearboxs into a screaming banshee

Than might have been a lubrication issue. What oil & how old? IIRC the guy from Award used to have a mod to help stop oil slopping to the back of the gearbox.

Or if the gears are case hardened perhaps the case hardening was worn through exposing the softer material underneath.

[The Bogan]

10 hours ago, MrStabby said:

Than might have been a lubrication issue. What oil & how old? IIRC the guy from Award used to have a mod to help stop oil slopping to the back of the gearbox.

Or if the gears are case hardened perhaps the case hardening was worn through exposing the softer material underneath.

Award built one after the car ate the original, with that oil mod thingie award does.

After that one was eaten they built another, that lasted a month or so, then after a run down the stip, that one started to whine.

Award said the OEM gears just weren't up to the level of torque. 

I found the torque rating for the box ages ago but I cannot recall what it was exactly, it was nowhere near 700nm though.

They recommened some brand of gears which were well out of my price range at the time, IIRC it was going to be $20k or something all up.

I sold the car at that point, it was to expensive to keep thrashing, one of the next owners put in that dog box.

It's a auto now though, doing roll racing at Eastern Creek.