I've got a few things I'd like to know about the auto.
About 6 weeks ago I did a full fluid flush on the auto, the following symptoms existed before the flush however they're noticeably reduced since.
Second to third gearshift is great on light throttle, give it half or more and it is very unsmooth and non linear, quite hard to describe.
Kickdown from third to second at higher speeds is not right either, the box allows the engine to rev too high before engaging the gear, its perhaps 1/4 of a second too slow in engaging second on kickdown from third. This only happens if the revs are above about 2500RPM when it kicks into second, say above 60km/h.
I'd assume this is bands that have stretched or have worn friction material on them. Is this right and is there a link or instructions someone can give me to service this auto?
Now, a bit more technical. It's clearly obvious the auto shift pattern was programmed by a drunk monkey on vallium so I'd like to know if its possible to reprogram the shift patterns and shift speed electronically or if you need to drill the valve body as per older auto tranny's. Heres what i'd like improved:
On economy mode:
- Gearshifts to stay in the same point for throttle positions under say 15%-
- Gearshifts to increase in RPM for throttle positions between 15-50%
- Leave gearshift positions as they are for throttle positions above 50%
- If vehicle speed is above 45km/h, on flooring the accelerator, for the auto to NOT shift into first. Currently it will kick down to first up to 65km/h if you floor it. The engine is completely gutless above about 4000RPM and all this achieves is using a lot of fuel, making a lot of rattles vibration & noise, and not giving any useful acceleration. Vehicle accelerates considerably harder if you only give it 3/4 throttle and kick it into second, once you've exceeded 65km/h then floor it. Same deal for kickdown into second, prevent it happening above about 80km/h
-Adjust the torque converter lockup cluch so it engages in fourth gear at 74km/h. Currently it engages at 83km/h. At that speed and above, ensure it holds unless gearbox is kicked down into third gear with sufficient throttle (above about 25%). If the selector is in third, engage the TCC at 46km/h. I'm not completely certain of these figures because there may be excessive NVH at low engine speeds, however its what I'd like to try. I really enjoy a transmission thats directlly connects the engine to the wheels, not going through a fluid coupling. To tell the truth, I'd like the TCC engaged at anything above 15km/h in all gears but I dont know how rough that may make it.
On power mode:
- Stop the auto from kicking down to first above 50km/h and stop it kicking into second above 85km/h for reasons listed above.
- As the vehicle slows down, force the transmission to engage third at 70km/h, second at 40km/h and first at 25km/h for engine braking. This does not apply if the car is already in fourth at 50km/h or third at 30km/h etc, only if the car has been above the changedown speeds listed here.
- Leave the rest as is
So, can the auto be programmed to make it a nicer thing to drive?