Axle Temperature

[steve_d]

A friend has rebuilt a Capri rear axle replacing a broken bearing.
All is fine with no noise and all moves freely.
He put a temperature sensor on it when he did a relatively short road test and recorded 74 degrees C. (Don't ask why its just the way he is).
He is now asking me if this is OK and I have no idea.

Does anyone know if this is right?

If not, does anyone know what losses (BHP or percentage)you would expect on a 250BHP rated LSD Capri diff.? He tells me he will then calculate how hot it should be with those losses.

Thanks in advance
Steve

[Nick_F]

Probably about 35bhp soaked up by gearbox and axle combined.

70-odd degrees doesn't seem out of court, I've never checked one though.

[z1000]

If it's an LSD , then heat (friction) is what limits it slip

[GreenV8S]

I would guess at somewhere around 5-10% losses within the diff. The transmission can get very hot indeed if it is working hard (effectively it just gets hotter and hotter until you give it a rest, or it fails). But to gain 70 C in a few minutes of normal driving suggests it is generating an awful lot of heat and I suspect there's something wrong with it.

[Chris Wilson]

Perfectly OK, a diff cooler thermo switch would only usually trip over 95 degrees c, and synthetic diff oil is safe to 130 degrees. The CWP is the most hard worked gear set in the whole car. On LSD's using the Quaife type torque biasing set up, on serious race cars, in the wet, i have seen 150 C plus, with failed side seals and the oil coming out as if it's fried a million onions.