Down Shifting in Tiptronic mode

[Zanthus]

Hi All

This is my first post on Lextreme!
I've recently had a 1UZ-FE and auto/tiptronic gearbox installed in my '96 South African spec hilux 4x4. The pick-up has spent the past 3 month with the installers who specialise in only 1UZ-FE conversion about 800miles from where I live, because no-one close to even has a clue on how to do the convesion.

When I got it back I had lot of problems and week later they flew down and fetched it to sort out all the problems.

The thing that bothered me the most was the tiptronic gearbox. Being an offroad vehicle I need to be able to shift into 1st gear and it must stay there so I can use engine braking on steep decents. On my vehicle in tiptronic mode if I accelarate in a gear and let go of the throttle, it does not stay in gear, i.e. no engine braking. It then only goes back into gear if I rev it up to the point where it start to accelarate again. Is this correct?? Can you make use of engine braking in the tiptronic mode??

I can downshift to second in auto mode, but in tiptronic mode at the same speed the gearbox again goes into "neutral". Can you down shift in tiptronic mode??

Thank You
Barto de Koning

 

[sideshow]

it will not be able to engine brake in tip tronic mode

you have to physically move the shifter into L for engine brake and even then its not like a manual where it brakes instantly it tajes a sec or 2 to brake

with my tip tronic if u downshift it will freespin untill i touch the accelerator then it will
select the gear

not sure y it does this it might be normal

so what u are experiencing is normal tip tronic mode i think cause its similar to what my car does

so u either have to stick with it or move the shifter

 

[KDog]

due to the valving in the auto it is necessary to have both the shifter in 1st and the solenoids in the gear position of 1st gear to obtain engine braking in first gear.

 

[Zanthus]

My installer used a second hand shifter from an E-class Merc, because the genuine Lexus ones are 10 times the price and not available second hand. With that I can only shift down to 2nd. What do I do to make it go to 1st. Is it a matter of jut more stroke on the shifter, or does it involve electronics as well?

 

[spadger]

is it possible to change this so that it has engine braking? by modding the selector setup or the valves?

i wish to use this set up in a 4wd but it is useless to me if it has no engine braking ability

 

[sideshow]

talk to a local and experienced tranny shop

maybe they can modify the gbox to be full manual shift

and maybe with any luck u can use tip tronic to go up and down gears with engine braking

i think its much easier to go to a 5 speed manual with what yr tryin to do

anything can be done but do u have 10 or 20 grand to get it all to work how u want it

 

[GSMnow]

I don't know how your linkage lines up, but I used a 1983 Celica auto trans shifter in my 1UZ conversion, and the detents lined up perfect for all positions 1-2-D-N-R-P in the A341E trans. It does not have a tip-tronic gate, but you can put a pair of buttons anywhere. On the steering wheel spokes comes to mind. It did have the OD Off button, but the logic was backwards, so I added a relay to fix that. I also used a power/normal mode button from a late 80 Camry. The wrecking yard by me practically gave it away at like $20. Too bad the trim on it is blue, my interior is mostly black.

Gary M.

 

[Treynon]

Would downshifting not work with an a650e 5 speed also? Or would this be specific to the a34*e 4 speed line?