Race Car Tech Discuss anything related to road racing and auto X.

? about Dog box transmissions.

Old 11-15-04, 01:36 PM
  #1  
Full Member
5 Year Member
Thread Starter
 
Join Date: Aug 2002
Location: MN
Posts: 164
Likes: 0
Received 0 Likes on 0 Posts
? about Dog box transmissions.

i was mainly wondering how it functions...
7knight is offline  
Old 11-15-04, 02:16 PM
  #2  
Slam Pig
10 Year Member
 
Join Date: Dec 2002
Location: New York
Posts: 888
Likes: 0
Received 0 Likes on 0 Posts
whoops....
obviousboy is offline  
Old 11-15-04, 02:40 PM
  #3  
Lives on the Forum
15 Year Member
 
DamonB's Avatar
 
Join Date: Feb 2001
Location: Dallas
Posts: 9,617
Likes: 0
Received 0 Likes on 0 Posts
In general a dog box is more compact and robust while allowing quicker shifts at the expense of being noisy and intolerant of improper rev matching or shifting. They also always make a swell "ka-chunk" noise when you put them in first The dogs themselves are large flat teeth on the faces of the gears that interlock when meshed together; they are what provide the physical coupling of the gears to the output shaft.

Pic 1 shows the dogs on the gear faces. These will mesh with the shift select collar that also has dogs on it's faces. The collar is indexed to the output shaft so whenever it is pressed against a gear that gear is selected.


pic 1

pic 2

pic 3

Last edited by DamonB; 11-15-04 at 04:15 PM.
DamonB is offline  
Old 11-15-04, 07:09 PM
  #4  
fd0
formerly chillin_rx7_guy
10 Year Member
iTrader: (8)
 
fd0's Avatar
 
Join Date: Mar 2003
Location: WA
Posts: 1,149
Likes: 0
Received 0 Likes on 0 Posts
I don't know about you guys but when I see all those pics of transmissions with all those gears, it makes me feel good....
fd0 is offline  
Old 11-15-04, 11:29 PM
  #5  
Full Member
5 Year Member
Thread Starter
 
Join Date: Aug 2002
Location: MN
Posts: 164
Likes: 0
Received 0 Likes on 0 Posts
thank you damon... that one paragraph was more insightful than most websites i was able to find..
7knight is offline  
Old 11-16-04, 04:54 AM
  #6  
www.lms-efi.com
iTrader: (27)
 
C. Ludwig's Avatar
 
Join Date: Mar 2001
Location: Floyds Knobs. IN
Posts: 5,106
Received 30 Likes on 23 Posts
The "dogs" are similar to the corresponding pieces of a synchro box. The difference is that the synchro ring rides between the sets of dogs and helps match the speeds of the gearsets. In most dog boxes not only are the dogs themselves much more robust but the gears are generally straight cut (as the one Damon posted pics of) versus the helical cut of a production transmission. Not only are the straight gears stronger but they give that o-so-sweet whine.
C. Ludwig is offline  
Old 11-27-04, 06:30 PM
  #7  
Junior Member
5 Year Member
 
formula-mazda's Avatar
 
Join Date: Nov 2004
Location: socal
Posts: 13
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by C. Ludwig
The "dogs" are similar to the corresponding pieces of a synchro box. The difference is that the synchro ring rides between the sets of dogs and helps match the speeds of the gearsets. In most dog boxes not only are the dogs themselves much more robust but the gears are generally straight cut (as the one Damon posted pics of) versus the helical cut of a production transmission. Not only are the straight gears stronger but they give that o-so-sweet whine.
I've only worked on dog boxes so I have never opened up a regular tranny. The gears on a dogbox are much stronger but the dogrings do not hold up to improper shifting. We have run a whole season (10,000 miles) without replacing anything on a tranny, but that is only with a driver that knows how to shift without damaging the tranny. I've also seen a Porsche GT car blow a tranny in 20 laps on a synchro box. I guess it all depends on the driver
formula-mazda is offline  
Old 11-29-04, 03:15 AM
  #8  
good to be back
iTrader: (8)
 
rexman13b's Avatar
 
Join Date: Apr 2002
Location: Kingsport, TN
Posts: 1,101
Received 4 Likes on 4 Posts
how can one convert a t2 tranny to full dog box? where do you find the parts to convert it over?
rexman13b is offline  
Old 11-29-04, 03:43 AM
  #9  
Rollin' coal and 53mpg!
10 Year Member
 
CHEF_EG_1's Avatar
 
Join Date: Oct 2002
Location: Jacksonville, Floriduh
Posts: 1,126
Likes: 0
Received 0 Likes on 0 Posts
CHEF_EG_1 is offline  
Old 11-29-04, 12:07 PM
  #10  
Armchair engineer
iTrader: (2)
 
j9fd3s's Avatar
 
Join Date: Mar 2001
Location: http://www.k2rd.com
Posts: 24,603
Likes: 0
Received 123 Likes on 112 Posts
Originally Posted by formula-mazda
I've only worked on dog boxes so I have never opened up a regular tranny. The gears on a dogbox are much stronger but the dogrings do not hold up to improper shifting. We have run a whole season (10,000 miles) without replacing anything on a tranny, but that is only with a driver that knows how to shift without damaging the tranny. I've also seen a Porsche GT car blow a tranny in 20 laps on a synchro box. I guess it all depends on the driver
yeah, its all driver. at the last enduro driver one gets out and says keep it in 3rd the synchro (with all of 3 hours on it?) is toast, driver #2 gets out of the car at the end of the race and said it was fine....
j9fd3s is offline  
Old 11-30-04, 02:55 AM
  #11  
Eats, Sleeps, Dreams Rotary
 
Valkyrie's Avatar
 
Join Date: Oct 2004
Location: Japanabama
Posts: 4,210
Received 6 Likes on 6 Posts
Does that mean you have to double-clutch and/or match the speeds manually?
Valkyrie is offline  
Old 11-30-04, 08:18 AM
  #12  
Rotary Enthusiast
iTrader: (1)
 
Join Date: Jul 2004
Location: Rocket City, Alabama
Posts: 1,035
Likes: 0
Received 1 Like on 1 Post
You must match the revs. If you are perfect, you can do it without a clutch.

The closer the ratios are in the tranny, then the less rpm change with each shift, so the easier it is to match revs.

When upshifting, with my very tight tranny ratios (only 1000 rpm drop with shifts) and my light flywheel, light 7" clutch and light rotors (lets my engine be willing to change revs quickly,) then I can rip off lightning fast upshifts for very quick acceleration.

Downshifting the dog ring tranny is tougher than downshifting a synchro box. I can double clutch downshift a synchro tranny very smoothly at any speed, but every now and then I mis match the revs downshifting the dog ring box and it makes the rear tires snap loose.

Last edited by speedturn; 11-30-04 at 08:21 AM.
speedturn is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
SakeBomb Garage
Vendor Classifieds
6
08-09-18 05:54 PM
George84
2nd Generation Specific (1986-1992)
8
09-28-15 11:58 PM


Thread Tools
Search this Thread
Quick Reply: ? about Dog box transmissions.


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: