Hello all. We have a 1985 Corvette comme into our workshop with basicaly a blown transmission. It has been fully rebulit . Customer is not content with lock up applying after 3rd gear is engaged. Lock up also applies after 4th gear is engaged as per normal. Question im asking is, is it possible to remove lock up between 3&4gear? Is this lock up standard for this model? Have anyone struck this problem before?
Any help at all would be much appreciated.
Thankyou.

 

in 1984 to1986 the 700 r4 are junk,replace it with a 1990 and up.and should have no problems.but if want some good info on that trany call fourth gear inc,phone #407-880-2882.these guys are the best in 700 r4'sspecialists. hope this helps.

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Hey i was just looking at an Ecklers catolog and found a TC lock-up delay harness, it states that eliminates lock-up in 1st - 3rd gears. if you go to Ecklers website type in part number 31993.

 

This is going to probably sound stupid but what is "lock up"?

 

A LOCK UP CONVERTER IS FOR OVERDRIVE.WHEN THE CAR IS IN THIRD AND GOING INTO 4 TH GEAR THE CONVERTER LOCKS UP SO IT CAN SHIFT INTO OVERDRIVE THEN WHEN YOU COME TO A STOP OR SLOW DOWN THE BRAKE PEDAL DISENGAGES THE CONVERTER FROM LOCK UP.IF THE LOCK UP CONVERTER WAS NOT WORKING THE CAR WOULD NOT GO INTO OVERDRIVE, HOPE THIS HELPS YOU OUT,

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"Lock up" is a term referring to clutches locking inside converter to give you direct drive through the converter, like having a manual transmission. More direct transfer of power means better fuel efficiency. Early 700's were contolled by vacuum switches and later models (4L60) were controlled by engine computer via actuators inside the transmission pan.

 

Why would he not be happy with it going into overdrive (if I understand your posts)?

 

The car could still go into overdrive without "lockup" occuring, particularly on older cars with 700R trasmission in them, because, as I found out, car has a 4th gear switch that is controlled by fluid pressure that grounds the lockup solenoid in the transmission pan. I was a little off, because early 80's 700's used an external vacuum switch along with a internal pressure switch.

 

I HAVE A 84 AND I HAVE A 92 700R4 IN IT AND DONT HAVE THE LOCK UP WIRE HOOKED UP ON IT,, I NEVER GET 4 GEAR,,,,A REGULAR CONVERTE SLIPS A LITTLE BIT ALL THE TIME .SO WHEN YOU STOP THE CONVERTER SLIPS THUS YOUR CAR WILL NOT STALL. MECH IS RIGHT THE LOCK UP IS LIKE A STICK IT IS DIRECT WHEN IT IS ENGAGED NO SLIPAGE.IF THE CONVERTER DID NOT UNLOCK WHEN YOU BRAKE THE CAR[STOP] THE CAR WILL STALL, MUCH LIKE A STANDER SHIFT IF YOU STOP AT A LIGHT WITH A STICK AND DONT CLUCH THE CAR IT WILL STALL.THEY SELL A FEW KIND OF OVER RIDES FOR THE LOCK UP TO TURN ON WITH A TOGGLE SWITCH OR BRAKE PEDAL.