Slight "whine" when in low range under trailing throttle

[Kumabear]

Ive always assumed this was normal, in my head I figured the low range gears were straight cut hence the noise. is this correct?

Thought I would double check my thinking on this before heading to Vic high country next month.

[shawty950]

I had the same thought just recently. Was doing some low range work then got onto some open 2 track and left it in low and got up to 5th on trailing throttle there was a slight wine / ticking noise. My initial thought was stick/stone caught in abs ring gear...nup...did a test back in 4high locked went away, back in 4low came back. Wrote it off , like u to low range straight cut gears (from previous 4wd that had them)...but not certain.

[Pauno]

Couldn’t find any other thread with information so thought I would continue with this one.
I have noticed the same thing when in low range, never noticed it before but havn’t ever used low range before where I have had a trailing throttle for any long period.
Was the conclusion this was normal??

[Keithyv]

Just normal I reckon. Whine sounds pretty cool IMHO.

[nj swb]

I've only ever noticed it with aftermarket reduction low range gears, which I put down to different manufacturing tolerances in the low range gears - or it could be the higher gear speeds for any given road speed?

The gears are not straight cut - not in the Gen 4, pretty sure they're not in the Gen 2 either.

Just thinking about it, is it the low range gears, or could it be that the transmission is being driven faster (on the trailing throttle) and there isn't enough road / wind noise to drown out the whine? The low range gear set is in constant mesh, but only under load in low range - but I guess it's only on over-run in low range that load will be transmitted through the "back faces" of the gear train?

[TomW]

I wouldn't worry to much, it will just be gear train noise due to the reduction ratio in low. If it makes you feel better my gen 1 has a real howl in low ratio under overrun (its been like this for years...), sounds like a race car with a straight gearbox.

[underdog]

I've always had a mild whinge when backing off in LLC. Pretty normal considering the amount of moving components under load with those kind of gear ratios.