Whining noise from transfer box

[DaveGee]

 My 2007 Rav4 has a whining noise which appears to be coming from the vicinity of the transfer box. Is this a common fault? the vehicle has quite a low mileage 42200miles. I contacted my local Toyota garage who quoted me £3600 for a new transfer box unit!!

Edited August 27, 2019 by FROSTYBALLS
Topic title edited to reflect subject

[the fox]

Try some new oil, not many people change the transfer box oil, it doesn't last for ever, easy job once the plastic engine/cover removed from underneath.

[furtula]

Does it happen in all gears/neutral, does the sound become louder with RPM?

Manual gearbox?

If you hold the clutch, does the sound go away?

 

[DaveGee]

Ben out for a long run today (150 miles) no trouble at all.  The noise seems to level out at 6o mph and can't be heard over this speed.  At slower speed the noise builds up around 40 - 50 mph and only in 4th or 5th gear when I take my foot off the throttle the noise goes away.  All oils have recently been changed. Manual gearbox.  To be honest after todays run I'm tempted to live with it,

 

[DaveGee]

7 hours ago, the fox said:

Try some new oil, not many people change the transfer box oil, it doesn't last for ever, easy job once the plastic engine/cover removed from underneath.

Oil changed recently.

[Ant-Rav]

I had a similar noise that a mechanic told me it is definitely the transfer box. Replaced box and made no difference. It was actually a front wheel bearing. Just my experience, don't spend load's of money until u are sure what is wrong, and It would be a second hand box I wud buy if it is the problem.

[DaveGee]

Thank you for you reply, I'm going to wait and investigate this further before spending that kind of money.

[furtula]

So the noise is there in 5th gear, but over 60 mph it just goes away?

I would do the following test, drive around 30 mph or so, when noise can be heard clearly, then press the clutch so that the transmission is not connected to the engine, is the noise still there?

While clutch is still depressed, rev the engine a few times, does the noise appear?

 

I know you can just do this while sitting, but better to replicate driving conditions.

 

Considering the age of the car, you can just get a used box and throw it in at an independent garage, with significantly lower cost than what Toyota quoted you for, if need be that is.

 

[DaveGee]

Thanks for this I'll give it a try.

[+robster+]

Done my front left wheel. Bearing last week  I could have sworn it was transfer box...it would hum and rumble above 25 mph at any left right straight ahead position until one day it maniffested itself as wheel bearing noise dissapearing on left turns when weight shifted to right hand side and lifted off the left.  All smooth now