Please explain how the gearbox work on my tiptronic

[Frans Reichert]

On my Ford, if I select 1st (remember it is also auto) and 4x4 the torque converter lock up, with very little slip, so I can go up a dune and it will just keep on until it is over or stuck, if I select "D" the slip on the torque converter is to much and I struggle to get it over the dune because it will come to a standstill and just stand there, no wheel spin nothing.

How do a complete "lockup" work with the tiptronic? do I select 4x4 and put the gear lever to "1" and loadpedal down.....

[Peter Connan]

Frans, the guy I know who does the most sand driving with a 4.8 tends to use mostly 2nd and 3rd Low, using Tiptronic.

However, he is currently in Moz, driving sand in his 4.8, and will only be back around the 15th I think.

I am not sure you can force TC lockup in the Patrol though...

[Frans Reichert]

Also I am still dum with the tiptronic, say if I select "3" will it change up to third gear and keep it there? Yesterday I tested it and keep it in "1" it hits the limiter, only changed when I push it forward to "2" will it lock up in "2" again until it hits the limiter?

[bogeyman]

Frans,
Welcome. Some great people on this forum.

As Piet said , engage 4l or 4h (depending on the severity of the sand and load) and use the tiptronic selector. 2 or 3 works well. If you don't get any power at the wheels , you are in the wrong transfer gear. Ditto if you dig in too easily. The correct tyre pressure also helps.

I have done a lot of sand driving with my gq4.5 auto and found that I get the best performance if I let the box do the selection.
I also have a 4.8 tiptronic and under most conditions I let the machine do the work. The torque converter has some slip , but it transforms revolutions into torque and if you apply a steady amount of throttle , the pull at the wheels is very steady and the wheels don't dig in. These motors have a solid torque delivery and there is usually more power than you need.
I have also recovered many stuck vehicles in deep sand that would not have been possible without the auto box.
Hope this helps.

Chris.

[Peter Connan]

Also I am still dum with the tiptronic, say if I select "3" will it change up to third gear and keep it there? Yesterday I tested it and keep it in "1" it hits the limiter, only changed when I push it forward to "2" will it lock up in "2" again until it hits the limiter?

AFAIK Tiptronic will hold the selected gear in any of 1-4th gear. I am not sure if 5th can be selected?

[Clem]

Also I am still dum with the tiptronic, say if I select "3" will it change up to third gear and keep it there? Yesterday I tested it and keep it in "1" it hits the limiter, only changed when I push it forward to "2" will it lock up in "2" again until it hits the limiter?

AFAIK Tiptronic will hold the selected gear in any of 1-4th gear. I am not sure if 5th can be selected?

On my 4.8 you can select anything from 1 to 5. It will not allow you (if the vehicle is moving) to select a gear that will cause the engine to over rev but once you have it in a gear it will hold that gear.

[Bruin Beer]

The Tiptronic only set the up-shift limit.
If the speed comes down to either reducing the throttle or increase in load the auto will shift down but will not shift higher than the selected Tiptronic gear selection.
Not sure if the torque converter will lock in the selected tiptronic gear.
I know if tiptronic 4th is selected it will lock in this gear and that is why guys like Chris Skinner tow his Ark usin tiptronic 4th to allow the TC to lock in forth.
Will have to test to see if TC will lock in the lower gear selection as well.
Will update if I can confirm this.
Bruin Beer.

[Bruin Beer]

Frans,
Here is a copy from the manual regarding the way the torque converter lock-up.

TC Lock.jpg (37.33 KiB) Viewed 14824 times

I also did a quick test this morning and can confirm that when in full auto (D), high range, the torque Converter (TC) start to lock at 120 to 125 Km/h depending on the load.
When in Tiptronic, high range, fourth gear (4) the TC start to lock at 105 Km/h.
When in low range, Tiptronic, fourth gear (4) the TC will start to lock at 50 Km/h BUT
When in low range, Full automatic (D) and fifth gear (5){I tried to count them from pull away} the TC start to lock at 40 Km/h.

Backing off on the throttle in low range or high range did not engage TC lock as explained by you the operation seem to be on the Ford. This in the 4.8GRX Autobox is handled by an over-run clutch within the gearbox to perform the engine braking to perform the action.

Looking at this you would need to keep this in mind when driving sand. If you are not able to get to fifth (full auto ), low range @ 40Km/h you would be better off going Low Range, Tiptronic, fourth (4) and maintain 50 Km/h as a minimum to get the TC to lock.

There might be some clever guys that can elaborate on this and possibly suggest better ways of utilizing this design and would appreciate any additional feedback.
Bruin Beer

[Clem]

Guys, how does it work in overrun? In "D" at anything much below 120km/h, there seems to be no engine braking but if I go to manual "4" or lower there is engine braking. That leads me to believe that below 120km/h, if you want engine braking you get lockup (or some degree of lockup) only in manual "4" or lower.

[Bruin Beer]

Clem,
This is a copy from the manual:

Over Run1.jpg (73.53 KiB) Viewed 14799 times

Over Run2.jpg (126.98 KiB) Viewed 14799 times

Hope this helps.
Bruin Beer