Tech / General Engine Is your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
Sponsored by:
Sponsored by: CARiD

Do you need a new speedometer gear when switching from 3.23 to 3.27 gears??

Thread Tools
 
Search this Thread
 
Old Jun 27, 2001 | 01:03 PM
  #1  
CamaroX84's Avatar
Thread Starter
Supreme Member
 
Joined: Sep 2000
Posts: 1,230
Likes: 0
From: Michigan
Do you need a new speedometer gear when switching from 3.23 to 3.27 gears??

My friend's rear end with a 3.23 gear just broke. I have a 3.27 rear that I am selling to him. He has an 85 IROC Camaro with the 16" rims. Will he need to switch speedometer gears? Or will it not be off by that much. Thanks in advance.
Reply
Old Jun 27, 2001 | 01:04 PM
  #2  
RB83L69's Avatar
Supreme Member
 
Joined: Jul 1999
Posts: 18,457
Likes: 16
From: Loveland, OH, US
Car: 4
Engine: 6
Transmission: 5
Probably not, it should be plenty close enough.

------------------
"So many Mustangs, so little time..."
ICON Motorsports
Reply
Old Jun 27, 2001 | 02:07 PM
  #3  
Vader's Avatar
Moderator
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Jan 2000
Posts: 19,680
Likes: 316
X84,

There is a 1.2% difference in the gear ratios. At 60 MPH the indicated difference in the speedometer would be 0.74 mph less with the 3.27:1 gearing. this si sroughly the equivalent of the difference created when new tires wear down to the point of replacement. The diameter change is more significant than the differences in your gearing. If you really want it to be dead-accurate, get tires that are ¼" larger in diameter.

------------------
Later,
Vader
------------------
"Let the bodies hit the floor!"
Adobe Acrobat Reader
Reply
Old Jun 27, 2001 | 04:38 PM
  #4  
89ROC's Avatar
TGO Supporter
 
Joined: Oct 1999
Posts: 533
Likes: 0
From: Ft. Worth, TX
Don't even worry about it, its not enough to make a difference.
Reply
Old Jun 27, 2001 | 04:49 PM
  #5  
Ed Maher's Avatar
Supreme Member
 
Joined: Sep 1999
Posts: 3,197
Likes: 10
From: Manassas VA
Car: 04 GTO
Engine: LS1
Transmission: M12 T56
I thought the factory only had a very limited combination of drive/driven gears anyway, and thus 3.23 and 3.27 cars have the same set as you can't match it any closer. Same w/ 3.42 vs 3.45s. I could be wrong though, i've never really looked at the speedo gear selections.
...ed

------------------
Ed Maher - Moderator @ The Carb Board
92 Z28 Convertible - Quasar blue / Tan top
LB9 4L60 GU2 G80 - stock, soon to be sleeper
-=ICON Motorsports=-

- Definitely prototypes, high powered mutants of some kind. Too weird to live, too cool to die
Reply
Old Jun 27, 2001 | 06:40 PM
  #6  
Grim Reaper's Avatar
TGO Supporter
 
Joined: Jul 1999
Posts: 10,907
Likes: 5
From: The Bone Yard
Car: Death Mobile
Engine: 666 c.i.
Ed, you are right. The difference is smaller than the smallest change you can make with a speedo gear change.

Do as Vader said and get one size larger tires.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
hectre13
Engine/Drivetrain/Suspension Parts for Sale
7
Aug 26, 2015 08:17 AM
Regal105
Transmissions and Drivetrain
4
Aug 23, 2015 03:45 PM
Dialed_In
Firebirds for Sale
2
Aug 20, 2015 01:45 PM
dhonda200
Transmissions and Drivetrain
6
Aug 11, 2015 11:50 PM




All times are GMT -5. The time now is 12:43 PM.