Gear Ratio change - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Transmission - Rearend
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 04-08-2003, 11:21 AM
Registered User
 
Join Date: Apr 2003
Location: New Jersey
Posts: 3
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Post Gear Ratio change

How do you do a gear ratio change? For instance, right now I'm running a 3.66:1 posi differential and if I just get under her (1978 Corvette) and take off the back housing of the differential, how hard would this be? Maybe change to a 4.11:1?

Maybe not, though. She's not a daily driver, but she's also not a racer. And I do want to keep her as stock as possible, so I don't want to do anything irreversible. I just want a little more acceleration from a higher ratio. But then again, I don't want to stress the engine too much (when I go on the highway with 4000+ RPMs) and be too inefficient.

Any ideas or thoughts on this subject?

Thanks!
TR

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 04-08-2003, 07:53 PM
bigwildgrin's Avatar
Rooster
 
Join Date: Mar 2003
Location: montana
Posts: 176
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Post

how hard would this be? well, pretty hard if you have never done it before. my first rear end change was a nightmare; the whole rear axle out and disassembled three times before I got it right. take it to someone who knows, and even better take it to someone who knows and will show you. I personally believe it's almost an art; I have a buddy who does it for a living and he slaps them in and sends them out the door so fast your head would spin. for me it's a weekend project.

I don't recommend going this way, but, you can also buy the whole assembled carrier unit. Chicago Corvette sells them complete and rebuilt, and I don't want to sound like a commercial for them but last time I checked they were $375 plus your differential, or $825 without. changing the differential isn't hard, just some general mechanicing. any corvette differential from 68-79 will fit (all are posi).

as for my opinion on what you should do, I have a '68 vette with 4:56 gears and I would trade you in a heartbeat. sure it will go from zero to 60 in the wink of an eye (in theory anyways, if you could ever get the tires to hook up), but with a four speed it's just too much. your shifting constantly and you can almost start out in fourth gear. take my advice and keep your gears; if she doesn't have enough ummph for you, you'll be happier if you spend that money on the engine. as for me, I'm holding out until I find a set of 2:77. the speedometer goes to 160, seems like the car should too.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 04-09-2003, 04:50 AM
Registered User
 
Join Date: Apr 2003
Location: New Jersey
Posts: 3
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Post

Okay, I agree with you. I'm just going to keep my current ratio. She has good acceleration, nothing that I'm unhappy with. just a thought. I see what you mean about starting in 4th gear.

Thanks!!

TR
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 04-10-2003, 07:17 PM
redcamaro4spd's Avatar
drive it like you hate it
 
Last photo:
Join Date: Mar 2003
Location: Central Va.
Age: 28
Posts: 311
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Post

I got a set of 2.73's out of a 1977 Camaro, I dunno what rear end size you got, but I'll sell them to you...lol

I desperately need a set of 3.73's...
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 04-11-2003, 04:35 AM
Registered User
 
Join Date: Apr 2003
Location: New Jersey
Posts: 3
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Post

Well I have a 3.36 so I wouldn't want to go backwards to a closer ratio, I was thinking something more along the lines of closer to 4. But I decided against this mod. Thanks anyways!

TR
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 04-11-2003, 07:01 PM
Member
 
Join Date: Apr 2003
Location: midwest
Posts: 37
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Post

I have done many vettes and its no big deal to drop the rearend, but as others have suggested it's hard to change the gears if you haven't done it before. You may also look around for a complete used diff with the right gears. 3:73 is perfect for street vette. I have had the most success with a 3:36 and a 700R4 trans. I just did a 74 and installed the 700 trans with the lock up converter. Very easy swap and the car flys with a 350 hp small block. good luck.
Reply With Quote Quick reply to this message

Recent Transmission - Rearend posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -6. The time now is 12:54 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.