ADD with manual Hubs

[GuerreroF]

Hi, I just bought a Toyota Land Cruiser (FZJ73) fron 1997, it has ADD (Automatic Differential Disconnect), and manual hubs... While driving on the free way, can I pulse the 4H button (with the hubs locked) for a "shift on the fly"??? If yes, does a speed limit for doing these exists??? (Hehe my english is a little rustied, sorry for that and thanks ).

 

[Toyo Boyo]

I used to have a 1992 Surf with ADD. The in car Toyota sticker stated that you could engage from 2WD to 4WD at speeds up to 100kph.

However, I never trusted the system not to explode if I tried - too many moving parts for my liking.

I only ever engaged when stopped or moving in 1st gear, slowly.

 

[SimonInAustralia]

While driving on the free way, can I pulse the 4H button (with the hubs locked) for a "shift on the fly"???

Not a good thing to be doing!

Engaging 4WD, with locked hubs, on a hard surface such as a sealed freeway, would cause transmission wind up, putting stress on the driveline and possibly breaking something.

Only put it into 4WD when on surfaces with less grip, dirt/sand/snow/ice/etc.