No engine fan = quieter getrag ???

[Butters]

Saw this video today from Adam LZ. 

 

Long story short is he is claiming that the load from the engine fan once the fan clutch heats up(engaged) is increasing the getrag rattle(at idle) when you don't have a dual mass flywheel. 

Before I go buying an electric fan setup .... Anyone heard of this ? 

 

I must admit when my car is cold the getrag is pretty quiet and I do notice the rattle after it is all warmed up. I've always assumed this is due to the gearbox oil temp and tolerances of metal. 
 

 

 

Edited yesterday at 12:32 AM by Butters

[GTSBoy]

The engine fan does draw a substantial amount of power. That's why they are typically so much more capable than an electric fan. So it is perfectly believable that the changed load on the engine (throttle/IAC more open, therefore less oscillation around the closed loop idle target rpm) would possibly lead to a change in the noise produced at the gearbox

But I would certainly not predict that it would transfer from car to car.

[MBS206]

4 hours ago, GTSBoy said:

The engine fan does draw a substantial amount of power. That's why they are typically so much more capable than an electric fan. So it is perfectly believable that the changed load on the engine (throttle/IAC more open, therefore less oscillation around the closed loop idle target rpm) would possibly lead to a change in the noise produced at the gearbox

But I would certainly not predict that it would transfer from car to car.

To add to this, I'd nearly suspect that if this IS happening on your own car, I'd seriously investigate the harmonic balancer. It's surprising some of the noises/oddities that occur in cars, can be an early sign of a harmonic balancer going.

This would be especially so since the part driving the loaded fan, is the pulley on the harmonic balancer. So any weird harmonics being caused by the fan, will be transferred to the harmonic balancer, if its getting old, or is a poor cheap designed one, it may not be sorting out the harmonics there, which would then be sent straight through the crank to the clutch.

[Butters]

At the time the box went in it was a brand new ATI 1000hp balancer. It's getting on a bit now but the noise from the box hasn't changed in the last 3 years. 

 

It would be interesting to try another one. 

I think I am going to experiment with taking the fan off with the motor hot and see if this actually works before I drop coin on a thermo fan setup.