How does the 4+3 Manual Transmission Overdrive work? - Corvette Forum

Go Back   Corvette Forum > C4 Corvettes, 1984 - 1996 > C4 Tech/Performance
Log In 
Register FAQ Search Today's Posts Mark Forums Read Vendor Directory
Search

C4 Tech/Performance
L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

How does the 4+3 Manual Transmission Overdrive work?

Reply
 
 
 
 
Thread Tools Search this Thread
Old 05-08-2010, 06:48 PM   #1
bigjohn85
CF Senior Member
 
Member Since: Jun 2006
Posts: 141
Thanks: 0
Thanked 0 Times in 0 Posts
Send a message via ICQ to bigjohn85
Default How does the 4+3 Manual Transmission Overdrive work?

I was looking to buy a late 80's corvette with a manual transmission and a seller was telling me that the button isn't in the stick anymore and when he is easy on the car it automatically goes into overdrive and when you are hard on it, it stays in the regular gears. Is this how the transmission suppose to work?
bigjohn85 is offline   Reply With Quote
Old 05-08-2010, 10:36 PM   #2
rodj
CF Senior Member
 
rodj's Avatar
 
Member Since: Aug 2000
Posts: 8,835
Location: Sydney Australia
Thanks: 0
Thanked 2 Times in 2 Posts
Default

Sort of.
The O/d is on every time you turn the key on.
When the right conditions are met ( varies by year ) , speed / engine temp /TPS volts; the O/d will automatically engage.It will also kick out back to direct drive when certain conditions are met ( hard accel, etc)
See
http://www.5speeds.com/43table.htm

The O/d can be turned off by using the button and then manually engaged when ever you want to
rodj is offline   Reply With Quote
Old 05-12-2010, 02:18 PM   #3
bigjohn85
CF Senior Member
 
Member Since: Jun 2006
Posts: 141
Thanks: 0
Thanked 0 Times in 0 Posts
Send a message via ICQ to bigjohn85
Default

thanks for the help. Makes a lot more sense now. do you suggest the six speed? I could just go up to a 89.
bigjohn85 is offline   Reply With Quote
Old 05-12-2010, 02:32 PM   #4
CAJUN C4
CF Senior Member
 
CAJUN C4's Avatar
 
Member Since: Feb 2000
Posts: 3,771
Location: MANDEVILLE, LA La
Thanks: 0
Thanked 0 Times in 0 Posts
Default

Quote:
Originally Posted by bigjohn85 View Post
thanks for the help. Makes a lot more sense now. do you suggest the six speed? I could just go up to a 89.
6 Speed,89'...Definatly. The early C4 4+3's were not very durable.If you , can..go with at least an 89' and get the ZF 6 Speed.
CAJUN C4 is offline   Reply With Quote
Old 05-12-2010, 02:52 PM   #5
techvette
CF Senior Member
 
techvette's Avatar
 
Member Since: Mar 2008
Posts: 991
Location: Houston TX
Thanks: 0
Thanked 0 Times in 0 Posts
Default

IMO, the 4+3's are fun to play with, but once the novelty wears off and the overdrive unit quits working you will wish you had the (more durable) 6-speed.
techvette is offline   Reply With Quote
Old 05-12-2010, 08:48 PM   #6
rodj
CF Senior Member
 
rodj's Avatar
 
Member Since: Aug 2000
Posts: 8,835
Location: Sydney Australia
Thanks: 0
Thanked 2 Times in 2 Posts
Default

Quote:
Originally Posted by Driver84 View Post
IMO, the 4+3's are fun to play with, but once the novelty wears off.
Some owners disagree
http://forums.corvetteforum.com/c4-g...-all-time.html
rodj is offline   Reply With Quote
Old 05-13-2010, 12:14 AM   #7
FOURSPEEDVETTE
CF Senior Member
 
FOURSPEEDVETTE's Avatar
 
Member Since: Oct 2007
Posts: 3,325
Thanks: 0
Thanked 9 Times in 7 Posts
Default

In my early 1985 the O/D is never on automatically when the key is turned on. You must engage or disengage the O/D with a switch on the console. Later on the switch was mounted on top of the gearshifter. Otherwise it's just a T10 4 speed transmission. You can use O/D in 2nd 3rd or 4th gear. Just a note that the early 4+3 transmissions were very durable. Just not many people ever really knew how to use them and wound up damaging them through misuse.
FOURSPEEDVETTE is offline   Reply With Quote
Go Back   Corvette Forum > C4 Corvettes, 1984 - 1996 > C4 Tech/Performance
Reload this Page How does the 4+3 Manual Transmission Overdrive work?
 
 
 
Reply


Similar Threads
Thread Thread Starter Forum Replies Last Post
4+3 transmission and overdrive fluid capacities thecarnut C4 Tech/Performance 5 07-04-2015 10:59 AM
1984 Manual Overdrive jseremba C4 Tech/Performance 1 04-20-2015 12:35 AM
85: Overdrive died jerander C4 Tech/Performance 13 02-19-2005 10:16 PM
opinions wanted on an article I found on adding overdrive to a saginaw 4 speed tranny? Frankenvette C3 Tech/Performance 5 01-26-2004 11:20 AM
C4 4+3 Transmission...how does it work? Ilovetorque C4 General Discussion 2 09-27-2001 10:43 AM


Tags
1984, 43, 85, button, c4, corvette, engaging, manual, overdrive, schematics, transmissioin, transmission, vette, work, works

Thread Tools Search this Thread
Search this Thread:

Click for Advanced Search

Posting Rules
You may not post new threads
You may not 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 Off
Pingbacks are Off
Refbacks are Off

Forum Jump


 

All times are GMT -4. The time now is 08:31 PM.