tfperf

A friend just bought a 95 Z with a rebuilt 4L60E. It shifts very firm. The strange thing he asked me about was the fact that when the trans makes the 2-3 shift, instead of the car feeling like it jumps forward, it feels like it lurches forward then backward. I'm stumped. Anyone have any ideas?

Pro Built Automatics

Is this happening at part throttle? or at WOT?

tfperf

It happens at both part and full throttle. It seems to be more noticable at part throttle. I did get some info on the rebuild. There were super servos installed and some mods done to other internal parts, but nothing done to the valve body.

tfperf

anyone have any ideas?????

97blueZ28

sounds like the 2-3 shift solenoid is not working right, or the tranny had a ****-poor rebuild might also check torque converter lock-up

tfperf

The trans seems to shift fine except for the 2-3 shift. The converter doesn't lock up until 45 mph.

97blueZ28

then its prob the solenoid or maybe some **** bands were used in the rebuild, better to have someone look at it, also has he moded the comp to move shift points?

Pro Built Automatics

Do you (the driver) have the sensation of going headlong (forward), during the 2-3 shift, when this happens?

tfperf

When I drove the car and it made the 2-3 shift, it initially felt like the car was surging forward. Then is felt like it surged backwards. It did this forward then backward surge on every 2-3 shift.

He says the shift points weren't modified. It does have a fairly loose converter in it. I got it to brake stall to about 2900 before the tires let loose.