Ok, Im new and looking for some information on going from the 3sp auto to a 4speed auto in my 92 Z24 vert.
Can it be done? If so who has the info I need?
I got the car from a lil old lady and its in great shape.
Its blue with a white top, white pleather interior and so stock it is unreal.
found the broadcat sheet under the hood blanket/instulation
Soooo nobody has done this or has any info @ all ? Im just looking for better mileage by adding a 4th gear.
3spd is better gas mileage then the 4spd cause the gears are longer. you're not simply adding another gear, the gears are shorter so you'll go through them faster then the 3 does...id just leave it, not worth the work
well this topic has been talked about alot on v6z24.com the main difference is that 4 speeds are computer controlled
so yea it would be best for you to get a 5speed swap
@!#$ happens
What about a TH440 from an older GM FWD V6, say like the one in my '88 Celebrity that is hydraulically shifted and controlled by a TV cable.
ohvrolla wrote:What about a TH440 from an older GM FWD V6, say like the one in my '88 Celebrity that is hydraulically shifted and controlled by a TV cable.
Even though it's about a Fiero there's still alot of good info. I've been thinking about this same swap myself but there are more low mile TH125's in junkyards near me than there are TH440's and the low mile TH440's they do have they want almost double $$$ than a TH125.
I've been thinking the same. I have an 88 Z24, and was thinking about putting in a 4 speed auto as well. I don't see how a three speed gets better fuel mileage. To me that is ridiculous. Also considering all the newer cars with 5 and 6 speed autos. The easiest way would be to use a 4 speed of the same vintage. One that's not electronically controlled. My only question is how different the dimensions are, and if the output splines for the axles are different.
