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4+3 overdrive switch

Joined
Dec 19, 2001
Messages
43
Location
Canton, OH
Corvette
1988 Flame red coupe 4+3
OK, I've "lurked" long enough. Been reading posts for a couple months now. What a great forum!! Bought my 1st Vette this November. Waited WAY too long( 34 years). Now I need some help. Overdrive switch does not work on my 4+3. Dealer told me this when I picked it up. Also told me they were not available thru GM any more. I've emailed a couple of the vendors in the portal project a week or ten days ago, but haven't gotten a reply yet ( OK, should've called but haven't had time) Does anyone out there know where I can pick up a switch, either new or a good used one. Any info is greatly appreciated. Want to replace it before spring arrives. Thanks, Murf.
 

vigman

Motor head!!!!
Joined
Feb 13, 2001
Messages
3,471
Location
Valencia, CA,USA
Corvette
88 Convert ( SOLD ) /1973 coupe 4 speed/1964 Vert!
Look up a few posts

Ken's repository of Doug Nash 4+3 info is the kind.

Have you read it yet?

Welcome

Mike
 
Joined
Dec 19, 2001
Messages
43
Location
Canton, OH
Corvette
1988 Flame red coupe 4+3
Thanks for the quick replies. I read and printed out all 9 pages of Kens 4+3 info about a month ago. Service manual doesn't show switch in shift knob. I'm assuming that the switch is the one below the t rod and actuator block. You're right. Trying to find one is tough.
 
Joined
Dec 19, 2001
Messages
43
Location
Canton, OH
Corvette
1988 Flame red coupe 4+3
Sorry Len, should've read a little slower. Symptoms. Overdrive is always on. Pressing switch knob doesn't turn it off. Accidently hit knob while driving on interstate a while back and OD did turn off. Had to press switch knob about a hundred times to get it back on. Haven't tried it since. Much better off, stuck in OD than not. OD will kick out on acceleration. Seems to work ok, just can't shut it off when I want to.
Murf
 

GS Diva

Moderator,
Joined
Nov 1, 2000
Messages
2,308
Location
Conway, SC
Corvette
2016 Daytona Sunrise Orange Metallic Z06
Welcome!

I wanted to welcome you, Murf, first because you're a new member of the greatest Corvette site...and secondly, because you have an '88 with a 4+3 transmission, like me!! I haven't had a bit of trouble with mine but am always aware of the possibility so read and collect 4+3 information. I'm sure you'll find a solution here for your problem.

Lemon Peel aka Elaine
 

vette

Well-known member
Joined
Jan 20, 2002
Messages
157
Location
seymour ct usa
Corvette
1966 coupe
overdrive not working

murf, try taking the button out of the shifter and turn the t bar that will adjust it. many times thats all it takes. the button should sit just a little higher than the shift handle. so i would try turning the t bar so it will raise the button.
 

Ken

Gone but not forgotten
Joined
Jan 30, 2001
Messages
8,237
Location
Hermosa Beach, CA
Corvette
1987 Z51 Silver Coupe
Hi Murf, if you already have, as you said, printed my pages on the DN 4+3, then you know as much as I about the subject. The only thing I can say as far as acquiring a new switch would be to check with any local dealers to see if there are any switches left over in their inventory. I think mine came from the dealer when I replaced it a few years ago.

You can also check with Paul at The Gear Zone to see if they have a switch. Their web site states that "All other hard parts always available.", so you might want to check with them.

Good luck with the transmission.
 
D

djscomp

Guest
How do you take the switch button off without breaking anything?
 
Joined
Dec 19, 2001
Messages
43
Location
Canton, OH
Corvette
1988 Flame red coupe 4+3
Take a small screwdriver and gently pry the button at the front and rear. It will come right off with no problem. It just snaps onto two pins.
Murf
 
D

djscomp

Guest
OK, I did that and turned the T pin to raise it up and down and it still does not come out of overdrive. Any suggestions would be appreciated. Thanks
 
Joined
Dec 19, 2001
Messages
43
Location
Canton, OH
Corvette
1988 Flame red coupe 4+3
I tried the same thing. Had to replace the switch. Adjusting the rod did not work. Try Radio Shack. Part # 275-1549a. Should be around $3 or 4. Be careful when taking it apart. You do not want to lose the spring (like I did ). No replacements are available that I know of. When you replace the switch, solder the wires on and cover the connection with hot glue, similar to old switch. This prevents movement at the connection. Good luck.

Murf
 

gmhowe

Well-known member
Joined
Nov 14, 2002
Messages
437
Location
glendale, az
Corvette
1985 4+3 black cpe & 96 LT1 CE
There was another thread sometime earlier that showed a replacement switch that TYCO makes for about $12.00 I used it to replace mine. It had the part number also.
 
D

djscomp

Guest
Is this the switch under the center console? I just ordered one for $49. I think I may be paying a little too much!
 
Joined
Dec 19, 2001
Messages
43
Location
Canton, OH
Corvette
1988 Flame red coupe 4+3
The switch is at the base of the shifter just above the linkage. Not only must you remove the center console, you also have to remove the cover for the dash and the radio to access the screws to remove the console cover. The shift knob has to be removed also. Take the knob off, unscrew the t-rod, counting the number of turns to remove it ( important). Pry the wedge (silver colored metal tab) out and unscrew the shift knob before you can remove the console cover. The switch, spring, and wiring harness will be right there. Be careful when you remove the switch. DO NOT LOSE THE SPRING. Reassemble in reverse order. Screw the t-rod in the same # of turns it took to get it out. Good luck.

Murf
 

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