Upshift Light

[Harry1987]

Just had rear end gears changed to 3.55 from 2.59 along with speedo gears to keep speedo and odo correct. (Automatic tranny) Driving on highway, felt shift into overdrive but at about 2200 RPM, 73 mph upshift light comes on. Never happened before gear changeout. Does this mean my convertor is not locking up? How can I tell short of computer attachment? Is this a common occurrance a with stock chip? Fear I may overheat and blow tranny. Help

 

[Harry1987]

Anyone have any ideas??

 

[Eagle85C4]

Friend you picked the wrong day and time to expect an immediate answer....it is a saturday on a holiday weekend...most folks are out enjoying themselves. Might I suggest a bit of patience....someone will be along sooner or later to help you.

 

[Edmond]

Just had rear end gears changed to 3.55 from 2.59 along with speedo gears to keep speedo and odo correct. (Automatic tranny) Driving on highway, felt shift into overdrive but at about 2200 RPM, 73 mph upshift light comes on. Never happened before gear changeout. Does this mean my convertor is not locking up? How can I tell short of computer attachment? Is this a common occurrance a with stock chip? Fear I may overheat and blow tranny. Help

I think it has something to do with the ECM. I had a chip burned for me last year for a few subtle improvements. I'm pretty close to stock and after travelling for 15-20 seconds above 1500 RPM's in 4th gear, the upshift light comes on. I thought it was a fluke and my thinking was backed up when I asked the chip burner.

I believe that you'll have to have the ECM chip adjusted for the gear change.

BTW, what do you think/feel of the 3:55 from the 2:59. I have the 2:59's and it feels sluggish! Still kicks butt, but I wouldn't mind more.

 

[Harry1987]

Just got her back with the new gears Friday. Can definitely feel the difference. Richmond recommends a 200 mile break in so haven't gotten on it yet. My originally thinking was I didn't want to go to 3.73 because fear of wheels breaking free all the time, especially living in FL with lots of afternoon downpours. But with the 30 miles of driving I've done on them thinking maybe was too conservative.

While having them installed had rear end totally rebuilt minus clutchpacks which mechanic said looked fine. Also all new u-joints (6X). Purchased gears from Summit $319 and install and rebuild was another $1050.

 

[silver 80]

up shift

harry,
funny you should say that.
Mine does it every so offten I let off the gas just a little and then it goes away it only happened three or four times.

 

[Da Hawaiian Punch]

I might have the answer guy's!
when changing the gear ratio's, did you also change out the speed sensor along with the right speed-o gear's?
If the answer is yes to the speed-o gear, and no to the sensor, thats the reason why.
the speed sensor is what sends the speed, rpm's, and other info to the computer's on board.
try doing that and things should be back to normal guy's!!
Samething was happening to me when I switched out ratio's, from 2.59 to 3.07's.

 

[hawaii-5-lo]

what he said. not only that but your speedometer is probably a good 7-10mph off.later,Todd.