Autobox information

[dieselboy]

Hmmm....


With the number of 50mph limits around here, I'm definitely interested!

50mph is just above where the box locks up. its so annoying when you have to slow down a little and then you lose it :/

[Apache]

Yep, thats my main problem with the Surf autobox. I know the ECU programme for the box has to be a compromise to cover all eventualities, so the manual lockup would be an excellent mod. I aim to get started tomorrow, so watch this space.

I fancy a small illuminated pushbutton on the steering wheel to engage lockup, does anyone know if there are spare sliprings available? There must be some extra rings on the trucks with cruise control, are they fitted on all trucks? (just to save me taking the wheel off for a look)

[surfenstein]

Yep, thats my main problem with the Surf autobox. I know the ECU programme for the box has to be a compromise to cover all eventualities, so the manual lockup would be an excellent mod. I aim to get started tomorrow, so watch this space.

I fancy a small illuminated pushbutton on the steering wheel to engage lockup, does anyone know if there are spare sliprings available? There must be some extra rings on the trucks with cruise control, are they fitted on all trucks? (just to save me taking the wheel off for a look)

not on yours there wont be andy.

[dieselboy]

can i say good luck, and good on you for attempting this. i dont have the time, tools or patience right now. the only reason i have time to post here is because im on site and waiting for ppl to finish so i can start work :/

i dont think you would be able to adjust when it locks up variably without some sort of circuit board.. may be that can be a 'fine tuning part' but ON and OFF would help so much for everyone!

[Vixxen]

I have the A343F tranny. Is that basically the same as the A340F?

<edit> It appears so. The second '3' only refers to gear ratio.

[Apache]

OK, I think I know where I'm going with this now. I've found the output on the engine ECU for the lockup solenoid, and it seems lockup is active high. However, I am now unsure whether maintaining lockup will stop the box dropping out of O/D - which would be the ideal solution. I have a feeling it may still drop out of OD, but maintain TC lockup in 3rd gear, which is good as far as economy goes.

When I make this work, I'll be offering it to others.

<edit> I have enough info to have a stab at a basic version of this tomorrow lunchtime and report back tomorrow eve.

[BUSHWHACKER]

Lock-up and all the other gear shifts also rely on signals from the vehicle and engine speed sensors, so the trick is to fool these sensors to get the torque coverter to lock-up when you want it to.

[Apache]

Its actually a hell of a lot simpler than that. All that is required to force lockup is 12v on the lockup solenoid, so a 'break before make' switch to disconnect the ECU O/P and connect to 12v is all thats needed on a simple version.

A relay to do this is a better solution as it allows other control of the relay from whatever logic pattern I decide on to interject if necessary - and I haven't yet decided what that is to be. Full manual override should be easily possible too.

I'm gonna do the switch thing tomorrow lunchtime and get a feel for how the box handles a downshift between OD and third in lockup and work from there. I expect the programmable gearbox ECUs are doing fairly simple things but with lots of adjustability. Now I've got the diagrams and done some reading on how these things work, it doesn't look particularly complex.

[MattF]

I have all the info/diagrams you'll ever need, will post it all later.

What exactly have you got covered on disc Vince? Just Surf stuff, or owt else too?

[KERRSURF]

Looking forward to results and progress on this Andy, one of my only gripes with the gearbox on these trucks, hope your successful.

[Apache]

Will post further developments in the 'Modifications' section.