Problem after changing 87 corvette gears
Thread Starter
Advanced
Joined: Oct 2018
Posts: 55
Likes: 1
From: Jonesboro, AR
Problem after changing 87 corvette gears
I have a 1987 Corvette coupe with 17000 original miles. I had the 2:59 gears changed to a 3:54. Now, when I'm going about 55 the Upshift light comes on and the cruise control will kick in for a few seconds and then it sounds like it kicks out, and when it drops about 1 mph it kicks back in. Any ideas?
Melting Slicks
Joined: Aug 2003
Posts: 3,400
Likes: 396
From: Lakeville MI
Did you also correct your speedometer via the vss drive/driven gears or an electronic ratio adaptor?
If your speedometer (and input to ecm) has already been corrected, then the bin file (stored in the memcal/eprom) needs to be programmed to correct the 4th gear min and max n/v ratio and TCC lock/unlock speed settings. In other words, you need a "tune" for the gear change.
n/v ratio = rpm/mph
If your speedometer (and input to ecm) has already been corrected, then the bin file (stored in the memcal/eprom) needs to be programmed to correct the 4th gear min and max n/v ratio and TCC lock/unlock speed settings. In other words, you need a "tune" for the gear change.
n/v ratio = rpm/mph
Last edited by tequilaboy; Jan 30, 2019 at 12:28 PM.
Thread Starter
Advanced
Joined: Oct 2018
Posts: 55
Likes: 1
From: Jonesboro, AR
Did you also correct your speedometer via the vss drive/driven gears or an electronic ratio adaptor?
If your speedometer (and input to ecm) has already been corrected, then the bin file (stored in the memcal/eprom) needs to be programmed to correct the 4th gear min and max n/v ratio and TCC lock/unlock speed settings. In other words, you need a "tune" for the gear change.
n/v ratio = rpm/mph
If your speedometer (and input to ecm) has already been corrected, then the bin file (stored in the memcal/eprom) needs to be programmed to correct the 4th gear min and max n/v ratio and TCC lock/unlock speed settings. In other words, you need a "tune" for the gear change.
n/v ratio = rpm/mph
