MustangWorks.com : Ford Forums - View Single Post - Put 4:10's in my 94 gt auto, now my car wont shift right please help!!!

andy669 · 05-30-2003, 07:09 PM

The reason why your car is bouncing off the rev limiter between the 1-2 shift is because of the sloppy shifting trans. The problem has always been there with your trans, but putting the 4:10's in magnified it due to the quicker acceleration. A good shift kit will take care of that.

As for speedo calibration, the 94-95's are still an EEC-IV and dont require electronic programming. All recals are done mechanically via changing the drive and driven gears. The problem is the drive gear is machined in to the output shaft of the trans, and its 8 tooth. There is no such driven gear to compensate for 4:10's with an 8t drive gear. The closest you can get is a 23 (which is close for 3:73's) and the teeth on that thing are paper thin. I had mine rebuilt with a 7 tooth output shaft.

IMO 4:10's are too much for your car. With the 5500 rpm rev limiter and the stock size tire, your car is going to max out about 95-98 mph in drive.

Good Luck

Andy

05-30-2003, 07:09 PM	#8
andy669 Registered Member Join Date: Jan 2001 Location: Moline Il Posts: 901	The reason why your car is bouncing off the rev limiter between the 1-2 shift is because of the sloppy shifting trans. The problem has always been there with your trans, but putting the 4:10's in magnified it due to the quicker acceleration. A good shift kit will take care of that. As for speedo calibration, the 94-95's are still an EEC-IV and dont require electronic programming. All recals are done mechanically via changing the drive and driven gears. The problem is the drive gear is machined in to the output shaft of the trans, and its 8 tooth. There is no such driven gear to compensate for 4:10's with an 8t drive gear. The closest you can get is a 23 (which is close for 3:73's) and the teeth on that thing are paper thin. I had mine rebuilt with a 7 tooth output shaft. IMO 4:10's are too much for your car. With the 5500 rpm rev limiter and the stock size tire, your car is going to max out about 95-98 mph in drive. Good Luck Andy __________________ 88 coupe 91 LX NMRA Pure Street 5120