whats a "dog box"?

Author
Discussion

anonymous-user

Original Poster:

61 months

Tuesday 2nd April 2002
quotequote all
i mean gear boxes here, not canine kennels!
whats a "dog box" and why is it so good?

manek

2,977 posts

291 months

Tuesday 2nd April 2002
quotequote all
Non-technical explanation: as I understand it, it's a gearbox without synchromesh but instead uses straight-cut lugs (or dogs) to interconnect the gearwheels.

Experts feel free to tear that apart....

plotloss

67,280 posts

277 months

Tuesday 2nd April 2002
quotequote all
In a normal 5 speed you have whats called a 'Double H' where the two H's share their right and left edge, the standard 5 speed with reverse in bottom right.

In a dog box you have First at the lower left position then 2nd where first usually is and 5th where 4th usually is.

I think they are designed like this for racing as first is seldom used. There is probably a more technical reason with regards to the alignment of the actual cogs but I dont know about that.


Or...that could be a dog leg box, not sure!

Matt.

>> Edited by plotloss on Tuesday 2nd April 11:58

CarZee

13,382 posts

274 months

Tuesday 2nd April 2002
quotequote all
Hmmm.. maybe you're thinking of a 'box with Dog-Leg 1st Gear??

Layout is thus:

R 2 4
1 3 5

Advantage? novelty value I expect ..

alfa dave

950 posts

291 months

Tuesday 2nd April 2002
quotequote all
Manek is right, benefit is that due to greater tooth area it can cope with more power, downside is more noise and very notchy shifts. A real situation where double de-clutching would be beneficial.

Alfa Dave

Nick M (nmilton)

449 posts

289 months

Tuesday 2nd April 2002
quotequote all
Either double declutching or zero mechanical sympathy and a pair of industrial strength ear defenders !!

They're primarily for racing - clutchless changes can be made quicker with a dog box and they can, generally speaking, cope with more power than a synchro box.

richb

52,744 posts

291 months

Tuesday 2nd April 2002
quotequote all
quote:

Hmmm.. maybe you're thinking of a 'box with Dog-Leg 1st Gear??

Layout is thus:

R 2 4
1 3 5

Advantage? novelty value I expect ..

My 924 Turbo had a dog-leg first, it meant I was paranoid each time I left the car in the hands of someone else (other than a Porsche dealer) because it was so easy to reverse it away from the lights! Rich...

element

63 posts

272 months

Tuesday 2nd April 2002
quotequote all
928 manuals have this layout too

nevpugh308

4,414 posts

276 months

Tuesday 2nd April 2002
quotequote all
A lot (all ?) of Ferrari's have dog-leg boxes too (like my 308). Probably useful on a race track where, as mentioned, you (hopefully !) only use 1st once then use 2-5 the rest of the time. Just novelty on a road car (and slight theft prevention for idiot thieves .... it's not easy to get reverse (i.e. first to a numpty car nicker) without pushing the gear lever down first ...)

Mind you, a dog leg box does mean you occasionally forget which car you're driving, and go for an imaginary 6th where 5th is normally

pbrettle

3,280 posts

290 months

Tuesday 2nd April 2002
quotequote all
quote:

Hmmm.. maybe you're thinking of a 'box with Dog-Leg 1st Gear??

Layout is thus:

R 2 4
1 3 5

Advantage? novelty value I expect ..





Old VW Transporter vans used to have this layout. The main advantage from what I found was that you could scare the living be-jesus out of the people behind at traffic lights.... Did this many a time when you put it in Reverse and then move backwards once you are on green....

Managed to do it to a L driver once too - sorry if you are out there, I didnt mean it. Mind you, you should have seen their face - sheer panic....

Cheers,

Paul

kevinday

12,275 posts

287 months

Tuesday 2nd April 2002
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Lotus Sunbeam gearbox was a ZF box with dog-leg first, took some getting used too!

Roadrunner

2,690 posts

274 months

Tuesday 2nd April 2002
quotequote all
Sloppy seconds.

bennno

12,714 posts

276 months

Tuesday 2nd April 2002
quotequote all

what is a "dog box" ?

#it is a box to keep a dog in

#not to be confused with the dog's b###ox, which is something pretty cool

Bennno

>> Edited by bennno on Tuesday 2nd April 13:32

M@H

11,298 posts

279 months

Tuesday 2nd April 2002
quotequote all
Porsche 914's have the dogleg 1st too... what's worst is when you clip reverse on the way to second at speed!!

Cheers
Matt.

flying gibbon

2,244 posts

289 months

Tuesday 2nd April 2002
quotequote all
quote:

Layout is thus:

R 2 4
1 3 5




Actually, a little known fact is that this layout also appears on those small tipper trucks you see on building sites. Working one summer hols on site, no one told me about the gears until I started one up, put it in (what I thought was) first and let go of the clutch. It threw all its torque into reverse, tossing me over the wheel into the (fortunately empty) bucket at the front!

adrianr

822 posts

291 months

Tuesday 2nd April 2002
quotequote all
Manek is nearly right.

A standard gearbox has helical cut gears (gear teeth are skewed spirally across) and synchromesh to automatically match the speed of the gears when you change up or down and avoid gear grinding.

A 'dog box' replaces the synchromesh with pairs of plates with teeth (dogs) on. It allows you to change gear more quickly, once you've mastered heel & toeing. The really skilled can do this in nano-seconds without using the clutch at all.

A 'straight cut' box uses gears with straight teeth as you can make them bigger and stronger than the helical ones for the same size gearbox, so they can take more power. Downside is they whine like you're in reverse all the time.

Most competition gearboxes have both straight cut gears and dog engagement, hence "straight cut dog box"

AdrianR

CarZee

13,382 posts

274 months

Tuesday 2nd April 2002
quotequote all
quote:
Actually, a little known fact is that this layout also appears on those small tipper trucks you see on building sites. Working one summer hols on site, no one told me about the gears until I started one up, put it in (what I thought was) first and let go of the clutch. It threw all its torque into reverse, tossing me over the wheel into the (fortunately empty) bucket at the front!

anonymous-user

Original Poster:

61 months

Tuesday 2nd April 2002
quotequote all
cheers!, the subject wasnt covered in the "AA Book of the Car"..........

gee_fin

119 posts

290 months

Tuesday 2nd April 2002
quotequote all
Pablo - Bristol this weekend, get to the RPU. I've got the new six-speed sequential dog-box in. I'll demonstrate "look no left foot" changes

Find a straight enough, quite enough piece of road and you can have a try too.

Graeme.

________________________________________________________
graeme finlayson | tyre warmer | fluke motorsport
graeme.finlayson@vicorp.com | www.fluke-motorsport.co.uk

Barbados Rally Carnival Experience

manek

2,977 posts

291 months

Monday 8th April 2002
quotequote all
quote:

Manek is nearly right.

[snip]

AdrianR



Happens occasionally

>> Edited by manek on Monday 8th April 19:53