9 replies to this topic

[applemccann]

One of the mini's appeal for me is the classic transmission whine.  I think it's something to do with straight-cut gears rather than helical.  Do all models have straight-cut gears and are some more musical than others?

 

[GraemeC]

As standard, the Mini only ever had straight cut 1st & reverse.

[mab01uk]

One of the mini's appeal for me is the classic transmission whine.  I think it's something to do with straight-cut gears rather than helical.  Do all models have straight-cut gears and are some more musical than others?

 

No factory models of the Mini had a straight-cut gearbox but even the standard Mini transmission with helical gears has a more distinctive whine than most modern cars, a Mini modified for competition use often uses straight cut gears and especially the drop gears can make a loud noise which some like.....but would soon become annoying in a regularly driven road car.

 

If you walk round the race paddock of a meeting where Mini Seven/Miglias are moving around ready to go out for their race you will be able to experience the sound of straight cut gears close up.

Edited by mab01uk, 22 October 2020 - 12:17 PM.

[Northernpower]

The classic whine, sounds good for about five minutes. If you're inside the car and driving a reasonable distance you'll need ear defenders if you want to hear anything when you get out at the end. The whine most Mini's make is from straight cut drop gears not necessarily a straight cut box.

[Cooperman]

Tha SC gearbox whine is not too bad, even on a long rally.
However the SC drop gears are unpleasant. They are OK when a crash helmet is worn and really are just for competition.
I have never worked out why anyone would fit SC drop gears on a road car.
With a SC gearbox the gear ratios are much closer so 1st gear is quite high making a lower final drive ratio essential.

[Spider]

Perhaps the 'Mini gearbox whine' that you make think is SC Gears is an early idler gear as the bearings start going, causing the gear to lean over, that does make a whine, but it's not healthy.

[applemccann]

Interesting, thanks everyone. So racing SC mods aside (which is more of a scream than a pleasant whine) I've dug out a workshop manual to see what's standard. Looks like all engine gears are helical (drop gear, primary gear, input gear, idle gear, output gear etc). In the gearbox reverse and 1st are straight-cut with 2nd 3rd 4th helical. As GraemeC says.

 

I swear there's still some whine in 3rd and 4th though. In a good way, not in a worn bearing way. Maybe it's just the pitch of the helical gears in minis. 

[MrBounce]

Perhaps the 'Mini gearbox whine' that you make think is SC Gears is an early idler gear as the bearings start going, causing the gear to lean over, that does make a whine, but it's not healthy.

 

Mine did that (wasn't an early gear). For about 10 miles anyway. It did not end well...

 

 

 

It took out the idler gear, the transfer case and the gearbox. Amazingly it didn't do affect anything else... Yes those ARE gear teeth in the bottom left of the box...

[cal844]

 

Perhaps the 'Mini gearbox whine' that you make think is SC Gears is an early idler gear as the bearings start going, causing the gear to lean over, that does make a whine, but it's not healthy.

Mine did that (wasn't an early gear). For about 10 miles anyway. It did not end well...





It took out the idler gear, the transfer case and the gearbox. Amazingly it didn't do affect anything else... Yes those ARE gear teeth in the bottom left of the box...

Ouch looks expensive

[MrBounce]

 

 

Perhaps the 'Mini gearbox whine' that you make think is SC Gears is an early idler gear as the bearings start going, causing the gear to lean over, that does make a whine, but it's not healthy.

Mine did that (wasn't an early gear). For about 10 miles anyway. It did not end well...





It took out the idler gear, the transfer case and the gearbox. Amazingly it didn't do affect anything else... Yes those ARE gear teeth in the bottom left of the box...

Ouch looks expensive

 

Amazingly I got it back on the road for about £70 thanks to the generosity of friends helping out with parts, but it was 17 years ago...