Question for 4+3 owners
Thread Starter
Racer
Joined: Mar 2005
Posts: 288
Likes: 1
From: Maple Ridge British Columbia
Question for 4+3 owners
Do you have to use the clutch to engage overdrive orcan you just press the button? I'm wondering if you have to unload the drivetrain to engage the OD.
Melting Slicks
Joined: Apr 2002
Posts: 3,305
Likes: 2
From: Havelock NC
Well, it automatically engages once shifted into 2nd, but if you want to manually engage it you don't need to use the clutch. Mine shifts into OD fairly stiffly though so it doesn't hurt to hit the clutch.
Thread Starter
Racer
Joined: Mar 2005
Posts: 288
Likes: 1
From: Maple Ridge British Columbia
Yes, mine engages firmly as well. But then again, people with automatics put in shift kits to get the same effect, so I'm not sure if this is a bad thing? It would be nice not to have to use the clutch as essentially, you have a passing gear at highway speeds with the flick of a switch 
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Depends.
When upshifting to overdrive, I just hit the button.
For forced downshifts, I use the clutch, and bump the throttle before turning OD off.
On automatic kick down, no clutch. This is the feature that makes the 4+3 so cool. Comes in handy for passing quickly, eliminating the time taken to shift.
When upshifting to overdrive, I just hit the button.
For forced downshifts, I use the clutch, and bump the throttle before turning OD off.
On automatic kick down, no clutch. This is the feature that makes the 4+3 so cool. Comes in handy for passing quickly, eliminating the time taken to shift.
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Another great feature is the ability to force it to kick down when you come up on a cop. It wouldn't be friendly on the tranny at 80 mph, but hitting your brakes isn't always an option, and it sure beats paying a fat fine.
I drove an 87 once, and used the kickdown at 60 mph, and the f'n thing dragged the rear tires. That would suck going into a turn.
I drove an 87 once, and used the kickdown at 60 mph, and the f'n thing dragged the rear tires. That would suck going into a turn.
Racer
Joined: Feb 2005
Posts: 398
Likes: 1
From: Kelowna BC
Originally Posted by MacVette86
Yes, mine engages firmly as well. But then again, people with automatics put in shift kits to get the same effect, so I'm not sure if this is a bad thing? It would be nice not to have to use the clutch as essentially, you have a passing gear at highway speeds with the flick of a switch
I actually was wondering if a past owner may have put a shift kit in the O/D? I could not see anything when I serviced it last winter, but then again, I would not know what to look for
Fred
Race Director
Joined: May 2003
Posts: 10,749
Likes: 41
Originally Posted by MacVette86
Do you have to use the clutch to engage overdrive orcan you just press the button? I'm wondering if you have to unload the drivetrain to engage the OD.
It's a good practise too engage the clutch when switching into OD. I havent had a prob with my 88 tranny as of yet. Sometimes when u really want to kick it out of OD, and you want to go, you cant engage the clutch.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
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
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
Drifting
Joined: Dec 2003
Posts: 1,492
Likes: 94
From: Westfield MA
I always clutch it, the owners manual is silent on the subject, so you probaly don't have to, but I figure it can't hurt and might help. And it is good exercise for my left knee too...................
Drifting
Joined: May 1999
Posts: 1,478
Likes: 3
From: Sacramento, CA Money can't buy happiness - but it's more comfortable to cry in a Corvette than a Yugo.
Originally Posted by 88BlackZ-51
I need to service my 4+3 and rear end, Is there any good synthetics that you recommend?
Later I spoke to C4 guru Gordon Killebrew and he said he saw no problem with using synthetic in the OD, but he had heard of some people experiencing seal leaks between the manual trans unit and the OD unit which caused significant problems. The synthetic was slippery enough to get past the old seals and get into the OD. I came away with the impression that the best way to do it, was to use synthetic in both the OD and manual section or else non-synthetic in both. With both trans and OD being synthetic any leak shouldn't matter. So far however, I haven't experienced any problems with my current mix.
Race Director
Joined: May 2003
Posts: 10,749
Likes: 41
Originally Posted by Mike_88Z51
At 75k I replaced the fluids in my transmission, OD unit, and rear end. I used Mobil 1 synthetic gear lube of the GM recommended viscosity for the rear differential and the manual transmission. For the Overdrive section I used non-synthetic ATF per GM spec.
Later I spoke to C4 guru Gordon Killebrew and he said he saw no problem with using synthetic in the OD, but he had heard of some people experiencing seal leaks between the manual trans unit and the OD unit which caused significant problems. The synthetic was slippery enough to get past the old seals and get into the OD. I came away with the impression that the best way to do it, was to use synthetic in both the OD and manual section or else non-synthetic in both. With both trans and OD being synthetic any leak shouldn't matter. So far however, I haven't experienced any problems with my current mix.
Later I spoke to C4 guru Gordon Killebrew and he said he saw no problem with using synthetic in the OD, but he had heard of some people experiencing seal leaks between the manual trans unit and the OD unit which caused significant problems. The synthetic was slippery enough to get past the old seals and get into the OD. I came away with the impression that the best way to do it, was to use synthetic in both the OD and manual section or else non-synthetic in both. With both trans and OD being synthetic any leak shouldn't matter. So far however, I haven't experienced any problems with my current mix.
I always welcome your opinions sir, and I will do just that!
Curious, Did that LS-1 and the copter ever get you?
Last edited by 88BlackZ-51; May 28, 2005 at 05:35 AM.
Race Director
Joined: May 2003
Posts: 10,749
Likes: 41
Originally Posted by CentralCoaster
88black, check the thread on the 4+3 od filter, if you haven't already. It's in stock at your local autoparts store.
yeah thanks, i bought mine over the winter from eckler's.
