C4 speedo drive
Racer
Joined: Aug 2020
Posts: 362
Likes: 81
From: Indianapolis
What year and auto/manual? But I'd say no regardless. You'll have an electric VSS that turns rotation gear counts into a low and high-speed syn wave(s) that the ECM (on my '93) rectifies (right word?) into a signal the speedo/Cruis/ASB can use.
Ronn
Ronn
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
Speedo drive.
Some transmission shops sell a speedo drive that has a vss built in.
i bought one for my 57 chevy truck when i put the L98 and 4+3 in it. Speedometer is the original 57, and vss talks to the computer.
win win
i bought one for my 57 chevy truck when i put the L98 and 4+3 in it. Speedometer is the original 57, and vss talks to the computer.
win win
Pro
Joined: Dec 2018
Posts: 733
Likes: 424
From: Wisconsin
2023 Corvette of the Year Finalist - Modified
2022 C4 of the Year Winner - Modified
Finalist 2020 C4 of the Year - Modified
Your 85 uses an electronic sender, 4,000 pluses per mile. Goes directly to the dash and then to the ECM.
Melting Slicks
Joined: Mar 2001
Posts: 2,150
Likes: 304
From: Timra, Sweden
Starting from 1984 a VSS sensor replaced the wire in the th700r4. The internal drive inside the transmission is the same as for wire. The electric VSS signal go to the digial cluster that condition the signal. It is used internally for the speedo and also the cruise control that is built into digital cluster. The signal is also sent from cluster to ECU.
In the Camaro same years the analog speedometer is cable driven from the th700r4. At the back of the speedometer the electrical VSS signal is created that is used for cruise control and also sent to the ECU.
So the gauge mfg would have been right if it had been a Camaro but not for Corvette.
In the Camaro same years the analog speedometer is cable driven from the th700r4. At the back of the speedometer the electrical VSS signal is created that is used for cruise control and also sent to the ECU.
So the gauge mfg would have been right if it had been a Camaro but not for Corvette.
