) he was talking about a stick on account of the O/d relay reference.
85 lost overdrive
Thread Starter
Instructor
Joined: Dec 2004
Posts: 145
Likes: 0
From: Austin TX
85 lost overdrive
Finally got mine out of the garage and on the loop and had no overdrive. Since I had the throttle body off recently for the coolant bypass mod,( I remove the nipples and plugged em) I thought the TVS was out of adjustment so I reset it according the the FSM. Still no 4 th. gear, all other gears normal. I'm not sure were to go now, fluid is full and clean, although I have had a leak since I got the car 5 years ago. Maybe pull and inspect the governor next? My 91 Blazer also has the 700 R 4 and has an overdrive relay, but I can't find any reference to one on the Vette. Any ideas?
Last edited by Blackhole; Dec 8, 2009 at 09:11 AM.
Race Director
Joined: Aug 2006
Posts: 18,346
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From: D / FW
Sensors get gummed up with crap ! Had a 700 R 4 do the same thing in an IROC Z ! I was out of town so I put in a can of Seafoam Transmission conditioner which must have cleaned it up enough to drive a couple more years ! Tar that's the gummy stuff !
Le Mans Master
Joined: Aug 2000
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From: Australia
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Advanced
Joined: May 2003
Posts: 96
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From: Moreno Valley CA
Check OD switch
I don't know what year your vet is, however, ther is a switch on your brake pedle which signals the ECM when to engage and disengage the solenoid in the trans which locks it up. Some times this switch goes bad or loosens. I had this problem which turned out to be a loose switch at the brake pedle.
Hopefully this helps.
Gary
Hopefully this helps.
Gary
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
The brake switch is only there to break the circuit to the trans and disengage the lockup when you brake.
The OP's problem is no 4th gear ; not no lockup
