4+3 overdrive questions
Safety Car
Joined: Oct 2007
Posts: 4,426
Likes: 229
From: Pennsylvania
If I'm not mistaken you only need to hit the clutch when you initailly engage the overdrive, once it's on it will stay on until it's turned off. That's why you don't have to hit the clutch to engage the overdrive in second, third, and fourth when starting off in first if the overdrive is already on.
Drifting
Joined: Mar 2017
Posts: 1,897
Likes: 165
From: Nashville TN
2017 C4 of Year Finalist
Plain and simple of it. Operate 1st through 4th gear just like any 4 speed transmission. You may not even want to use overdrive. But if you do want to, use the overdrive only as a fifth gear. You only need to use the clutch once when you switch the overdrive on after 4th gear, and once when you want to turn the overdrive function off. No one drives a 4+3 the way described here. Unless they're an idiot. 
It's not a 7 speed transmission. 2nd gear overdrive feels like 3rd gear. 3rd gear overdrive feels like 4th gear. And 4th gear overdrive feels like a fifth gear. Fairly simple.
It's not a 7 speed transmission. 2nd gear overdrive feels like 3rd gear. 3rd gear overdrive feels like 4th gear. And 4th gear overdrive feels like a fifth gear. Fairly simple.
Safety Car
Joined: Oct 2007
Posts: 4,426
Likes: 229
From: Pennsylvania
Being that you have a 4+3, I'm sure you understand my next statements. But for those who don't know this, true, you can downshift in overdrive all the way down to 2nd gear without turning off the overdrive. When you come to a complete stop, the overdrive disengages automatically through the use of a vehicle speed sensor. If you leave the overdrive on, it will automatically engage back into overdrive in 2nd, 3rd, and 4th gear. 1st gear does not have the overdrive capability. Thus the 4+3 designation.
Drifting
Joined: Mar 2017
Posts: 1,897
Likes: 165
From: Nashville TN
2017 C4 of Year Finalist
Being that you have a 4+3, I'm sure you understand my next statements. But for those who don't know this, true, you can downshift in overdrive all the way down to 2nd gear without turning off the overdrive. When you come to a complete stop, the overdrive disengages automatically through the use of a vehicle speed sensor. If you leave the overdrive on, it will automatically engage back into overdrive in 2nd, 3rd, and 4th gear. 1st gear does not have the overdrive capability. Thus the 4+3 designation.
Le Mans Master
Joined: Aug 2017
Posts: 6,942
Likes: 1,490
From: New Jersey
This is how I use it. Only on the highway because spinning ~3k at 75 mph scares me a little... Sounds cool though.
Safety Car
Joined: Oct 2007
Posts: 4,426
Likes: 229
From: Pennsylvania
GM originally designed it for fuel conservation regulations back in 84-89. Some people actually think you have to shift it 7 times going down the road. Lots of bad/wrong information has been spread from know it all's who actually know nothing.
Drifting
Joined: Mar 2017
Posts: 1,897
Likes: 165
From: Nashville TN
2017 C4 of Year Finalist
That's exactly how it was designed to be used. GM originally designed it for fuel conservation regulations back in 84-89. Some people actually think you have to shift it 7 times going down the road. Lots of bad/wrong information has been spread from know it all's who actually know nothing.
GM originally designed it for fuel conservation regulations back in 84-89. Some people actually think you have to shift it 7 times going down the road. Lots of bad/wrong information has been spread from know it all's who actually know nothing.
Melting Slicks
Joined: Feb 2003
Posts: 2,677
Likes: 812
From: Saskatoon Sask.
Haven't done one but can you not just remove the C beam and unbolt it from the T10 with the 4 speed staying where it is?
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Drifting
Joined: Mar 2017
Posts: 1,897
Likes: 165
From: Nashville TN
2017 C4 of Year Finalist
Melting Slicks
Joined: Feb 2003
Posts: 2,677
Likes: 812
From: Saskatoon Sask.
Drifting
Joined: Mar 2017
Posts: 1,897
Likes: 165
From: Nashville TN
2017 C4 of Year Finalist
I don't think you can. Not enough room in the tunnel.
AND: The reverse idler gear shaft is part of the overdrive assembly. IIRC, the best way to assemble the OD to the 4-speed is vertically, so you can center the idler gear, then drop its shaft (which is attached to the overdrive) down onto it. Attempting to do it horizontally (as installed), the idler gear drops down, and the shaft won't go into it.
AND: The reverse idler gear shaft is part of the overdrive assembly. IIRC, the best way to assemble the OD to the 4-speed is vertically, so you can center the idler gear, then drop its shaft (which is attached to the overdrive) down onto it. Attempting to do it horizontally (as installed), the idler gear drops down, and the shaft won't go into it.
Drifting
Joined: Mar 2017
Posts: 1,897
Likes: 165
From: Nashville TN
2017 C4 of Year Finalist
Le Mans Master
Joined: Aug 2017
Posts: 6,942
Likes: 1,490
From: New Jersey
Racer
Joined: Dec 2003
Posts: 277
Likes: 3
I don't think you can. Not enough room in the tunnel.
AND: The reverse idler gear shaft is part of the overdrive assembly. IIRC, the best way to assemble the OD to the 4-speed is vertically, so you can center the idler gear, then drop its shaft (which is attached to the overdrive) down onto it. Attempting to do it horizontally (as installed), the idler gear drops down, and the shaft won't go into it.
AND: The reverse idler gear shaft is part of the overdrive assembly. IIRC, the best way to assemble the OD to the 4-speed is vertically, so you can center the idler gear, then drop its shaft (which is attached to the overdrive) down onto it. Attempting to do it horizontally (as installed), the idler gear drops down, and the shaft won't go into it.