reduction gears noise question

[Madmac]

i recently bought a gearbox and transfer case with 85% gearmaster gears fitted to the transfer case. i split the transfer case from the gearbox and bolted it to my gearbox. the reduction is awesome however at over about 20kmh in 4th or 5th it sounds a little whiney. is this normal or is there a problem. its only in low range, in high 4, or high 2 its fine. not sure if it should sound like this in low range or not. in low range in 1st 2nd or 3rd it sounds ok. just once i get above 20kmh in 4th or 5th it whines. is this normal because the gearing is so low. or is there a problem with a bearing or similar? ive never had reductoin gears in any of my rigs before so im not sure. and i dont want to ring the seller and go off the handle at him and make a fawkwit of myself if its normal. and yes it does have plenty of the correct grade oil in it

[ergjan19]

Yeah its deffiantely normal with reduction gears. Because the gears are spinning so much faster, you hear that whining noise.

I had an 85% reduction in my auto patrol and in only started to whine after about 25kmh.

Hope that helps.

[Madmac]

Yeah its deffiantely normal with reduction gears. Because the gears are spinning so much faster, you hear that whining noise.

I had an 85% reduction in my auto patrol and in only started to whine after about 25kmh.

Hope that helps.

thats what i was thinking, and thats what i wanted to hear. i dont really think it will ever get driven offroad at that speed in low range anyway. im still open to other opinions though

[GUEEY]

Yep my Rockhoppers do the same.
Completely normal for such a low reduction!

Grant

[Madmac]

cheers guys. just spoke to a mate on the phone, and he said its normal too. thats a load off my mind, thought for a brief moment that the purchase price wasnt such a good deal, relieved to know that its all good. wil it do harm to run it at 20-25ks in low range or am i better to just switch to high range and only engage low when needed. cant wait to test em at appin tommorow

[wtmudd]

The downside to reduction gears is that you have to spend more time in high range or put up with screaming your t*ts off to get any where (and chew up fuel). But let's face it, if you're doing over 20 kph do you really need to be in low anyhow? A good compromise is an airlocker in the back (to complement the one in the front) and then you'll find that high range is not too bad in the rough at lower speeds. My old GQ does 1.9 kmh at idle in low low and about 20 kmh in 4th at 2,000 rpm with Marks gears. And yes, the whine is part of the package.
Cheers,
wtmudd

[wtmudd]

The downside to reduction gears is that you have to spend more time in high range or put up with screaming your t*ts off to get any where (and chew up fuel). But let's face it, if you're doing over 20 kph do you really need to be in low anyhow? A good compromise is an airlocker in the back (to complement the one in the front) and then you'll find that high range is not too bad in the rough at lower speeds. My old GQ does 1.9 kmh at idle in low low and about 20 kmh in 4th at 2,000 rpm with Marks gears. And yes, the whine is part of the package.
Cheers,
wtmudd

[Madmac]

The downside to reduction gears is that you have to spend more time in high range or put up with screaming your t*ts off to get any where (and chew up fuel). But let's face it, if you're doing over 20 kph do you really need to be in low anyhow? A good compromise is an airlocker in the back (to complement the one in the front) and then you'll find that high range is not too bad in the rough at lower speeds. My old GQ does 1.9 kmh at idle in low low and about 20 kmh in 4th at 2,000 rpm with Marks gears. And yes, the whine is part of the package.
Cheers,
wtmudd

my rig is twin locked, detroit in the rear, air locker up front, hopefully in the next 12 months ill be able to change the gear ratios too. at present im running the stock 3.9s