tath

As above really

GavinE

It's cheap to produce, and seeing as reverse gear is only a very small part of a gearboxes life, the manufacturer can get away with it.

helical gears are actually slightly stronger than straight cut and you always have about 1.5 teeth engaged at the same time, while straight-cut you only have one.
But with straight-cut there's no lateral force generated like the helical gears, so you make more power at the output end of the gearbox.

Paulo P

iTrader: (42)

It's so old people know if they are driving backwards or forwards

dunx

iTrader: (3)

I would beg to differ....

Straight cut gears are stronger, but too noisy for mere mortals to endure !

Adding "dogs" just adds to the fun.

IMHO

DunxC

P.S. Right about the cheapness for reverse gear tho' !

tath

I believe straight cut gears are stronger for two reasons - because of the spur engagement there's no lateral force that needs to be restrained by bearings and they're made out of uber strong heat treated stuff. GavinE's right that there is more engagement on a helical one though.

And all boxes have dogs

GC8

Dog rings are alright for a Sunday afternoon: but Id sooner have synchromesh for the rest of the week.

GavinE

Quote
''Straight-cuts are stronger than helical gears is a myth. Helical cut teeth run quieter as they’re almost constantly engaged, also eliminating shock loads. They’re stronger through better tooth root design and more load-bearing area – the helical angle increasing overall tooth length and surface area by a small but appreciable amount''.

taken from here, however it is referring to Mini's, but surely it's the same principal.
Quit Whining – the truth about straight cut gears

Ginge !

iTrader: (1)

would have thought the reason is so you cant select reverse when going forwards or is that the syncromesh,,, been a while since i looked at a box

GC8

Helical gears are used instead of straight cut gears because theyre quiter. Thats the advantage; the disadvantage is that they absorb more power.

tath

Aye, because the force isn't acting in a straight line

Is that screaming an F1 car makes its gears?

Tidgy

no its the 19k revs that scream lol

GlesgaKiss

Screaming? You're probably talking about the fact that they rev to crazy rpm.

GlesgaKiss

Beat me to it.

Tidgy

great minds think alike

GC8

Its some of it: but its drowned out by the unsilenced 10 cylinder engine screaming at 19,000rpm!

tath

Someone told me that a lot of the whine isn't just the engine, it's the straight box.

GC8

The box whill howl like a banshee, but itll be completely drowned out by the engine. Havent you ever heard a Mini with a Jack Knight straight cut box?

tath

Not at 19000rpm