Auto transmission lockup ?

[Jumboshrimp]

Hello to all of the awesome Delica owners out there!

I have a 92 Chamonix automatic. I notice that at certain speeds in 3rd gear the lockup converter will engage. when the O/D off button is pushed the trans will not lockup.

So my question is how can I make it lockup with O/D off? I think this would help lower rpm's when O/D is not being used.

any help/input is greatly appreciated!

[Growlerbearnz]

Short answer: you can't.

Disabling O/D also disables TC lockup, and that behaviour is designed into the hydraulic control "brain". In theory you could modify the hydraulic control circuits to achieve anything you wanted, but the system is far more complicated and finely-tuned than anyone thinks, and modifying it is fraught with unintended consequences.

How intimidating is this?:

ATcontrol.PNG (256.1 KiB) Viewed 3549 times

Volvos use the same transmission and there's a healthy FAQ on the Volvo page here, including a guide to some modifications of the control circuits: https://www.volvoclub.org.uk/faq/TransmissionAuto.html

There's a downloadable AT workshop manual here: http://www.delica.ca/forum/viewtopic.php?f=115&t=7347

[Jumboshrimp]

That’s what I was afraid of.
Darn
I knew you would have the answer !

More like “Gurubearnz”!

Cheers