Gearbox hot to touch after motorway drive

Sounds a good piece of advice will check it out and post my findings.

 

Mostly a gearbox with wear sounds like a Renault Zoë at low speed. Different worn bits cause drone with engine speed or with wheel speed.

A gearbox gets warm because of some friction in bearings and stirring the oil around against the viscosity. Its has to be sticky and viscous to stick to the gears so it is present when the spinning gears mesh and be capable of being crushed as the teeth slide, and make the synchromesh elements drag just enough to spin up the gears.
At the same time it needs to flow easily to avoid wasting energy..


Until I fitted new sound insulation to the engine bay, I had got used to the sound of my gearbox. 60000 miles ago it was swapped and the new one was louder than the old one that basically lost first and third gear after a trip to Cornwall (not any external linkage issues) , but which gave little sign of failing until a trip to the chippy on arriving home., although originally I had had to stop about 4 times to tweak the gear lever when I first drove the bus 120 miles home.

So gearbox noises and heat are not a sign of impending failure.

I will be doing some long high speed runs on the M4 in a couple of weeks and I will shoot it with an IR thermometer gun if I remember.

 

If all you have to worry about is the gearbox being warm to the touch your doing well just get out and drive it.

 

So gearbox noises and heat are not necessarily a sign of impending failure.


@Steven Mitchell this type of bits in the oil is bad news


You should have heard the racket this made.

 

A lot of performance cars have transmission oil radiators, some even have them for the diff....even some mundane cars have them.

Try touching a motorbike chain after a fairly normal ride.....actually don’t....you’ll burn your fingers.

If you think about all that oil absorbing the friction forces as the gears mesh, it will get hot.

 

Jesus, that’s depressing stuff.

 

Yeah, took hours in therapy at the bar, that one did one the brightside, it makes a good story to tell

 

Haha, it’s good not to wallow in self pity and simply crack on.



Bet the bank account cried itself to sleep each night though.

 

You could say that, yes..... specially harsh for a Yorkshireman.

 

I just went for a drive around today, moved some stuff for a friend. After about 8 miles, the engine oil temperature was 80 degrees C so that was a bit too hot to touch. The gearbox was warm to the touch.
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