4+3 overdrive unit not working
Thread Starter
Burning Brakes
Joined: Nov 2003
Posts: 844
Likes: 0
From: Cape Cod Ma
4+3 overdrive unit not working
My overdrive was kicking in and out a week ago. Now I changed the fluid in the O.D. and it dosn't work at all. On another post there was something about it could be a sensor on the overdrive itself, when gumed up this sort of thing could happen? Or a relay? The cars an 85 with the swich on the console.
Anyone tell me where the relay for the unit is and how to clean up this sensor and how to remove it .Anyother imput would be great. :cheers:
[Modified by redfast, 11:07 PM 5/23/2004]
[Modified by redfast, 12:22 AM 5/24/2004]
Anyone tell me where the relay for the unit is and how to clean up this sensor and how to remove it .Anyother imput would be great. :cheers:
[Modified by redfast, 11:07 PM 5/23/2004]
[Modified by redfast, 12:22 AM 5/24/2004]
Drifting
Joined: Mar 2003
Posts: 1,828
Likes: 214
From: Charlestown IN
Cruise-In V Veteran
Re: 4+3 overdrive unit not working (redfast)
:cool: you've got an 85. So do I. If it was fine before you changed it, check the level again, if you haven't already. I had to add another 3/4 quart after having one put in and filled. After I drove it a bit, it dropped that much.
Do you have the switch on the console or the shifter ****? If your vette will move, your overdrive is still alive. Does the overdrive lite come on?
There's a relay under the hood and a pressure switch inside the unit. Scorp is the man on these :yesnod:
Do you have the switch on the console or the shifter ****? If your vette will move, your overdrive is still alive. Does the overdrive lite come on?
There's a relay under the hood and a pressure switch inside the unit. Scorp is the man on these :yesnod:
Thread Starter
Burning Brakes
Joined: Nov 2003
Posts: 844
Likes: 0
From: Cape Cod Ma
Re: 4+3 overdrive unit not working (scorp508)
Before the unit kiked in and out of overdrive wile going above 55-60 mph. The fluid looked not so good (not burned) so I changed it. Now it does nothing. The car drives fine but no O.D. I'll check it again but I did get more than 1.5 quarts in it. How much dose it take? :thumbs:
Drifting
Joined: May 2002
Posts: 1,509
Likes: 3
From: Hazel Park MI
Re: 4+3 overdrive unit not working (redfast)
Redfast, the overdrive relay should be on the firewall next to your wiper motor. It is the furthest relay from the drivers side on the firewall, and looks like the relay behind the battery. :seeya
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Re: 4+3 overdrive unit not working (jmrl98)
Check your OD relay (it's the one in front of the fuel pump relay there), make sure the exposed wires aren't shorting. Make sure the harness isn't melting against the smog tubes.
After driving it, top off the unit (you need to fill up the cooler lines, and you can't do that without turning the drivetrain.)
I'd also try hooking up a 12V switch directly to the terminal on the side of the case and activate it while driving to see if your problem is internal (pressure switch or solenoid or fluid level) or external.. between that terminal, the relay and your console switch.
If all else fails, verify that you have the filter and grommet seated correctly.. its more difficult than it seems, and those filters tend to cut the grommets easily and suck in air if the fluid is a teensy bit low.
Does the overdrive light on the dash work in unison with the switch or just when the car is actually in overdrive?
After driving it, top off the unit (you need to fill up the cooler lines, and you can't do that without turning the drivetrain.)
I'd also try hooking up a 12V switch directly to the terminal on the side of the case and activate it while driving to see if your problem is internal (pressure switch or solenoid or fluid level) or external.. between that terminal, the relay and your console switch.
If all else fails, verify that you have the filter and grommet seated correctly.. its more difficult than it seems, and those filters tend to cut the grommets easily and suck in air if the fluid is a teensy bit low.
Does the overdrive light on the dash work in unison with the switch or just when the car is actually in overdrive?
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Team Owner
Joined: May 2002
Posts: 24,337
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From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Re: 4+3 overdrive unit not working (redfast)
Yes, the O.D light comes on. But no work. :thumbs:
