Auto Box - TDCi

[marcusturbo]

Just a general question to you guys that have a diesel with the 6 speed auto box.

When driving about the streets at slow speeds it feels like and sounds like the clutch is slipping!!! Example, driving about the streets, approach a corner, slow down and box selects 2nd gear, as I apply throttle, just enough, the revs rise to just over 2thou, the car is still gaining speed slowly but the revs are not increasing and it sounds and feels exactly like a manual car with a slipping clutch. The garage have checked it out and say that it is characteristic of the box but I'm not convinced. Not had the time but I'm going to go ask them if I can test drive a similar car and see if it does the same.

I only get the problem as low revs is 2nd and somethings 3rd. The rest of the time the box is perfect. I also get this problem if I have the lever over to the right and selecting the gears manually.


Any ideas or similar happenings??

[NZ XR6]

It's the torque converter doing what it's name says. I think it's quite normal - although mine's petrol it does something similar at low speed and light throttle, especially until it's fully warmed up. I've now changed my driving style to avoid it - I just use more throttle!

[fordmondeoman]

mine is a auto as well what you are feeling is the torque converter as mentioned above. reason you feel this more when at lower speeds is that, the converter is stalling up or as you describe it slipping, so you know a torque converter is full of oil and uses oil to transfer power to the auto.
Now newer cars have a torque converter lock up clutch that locks the two sides of the converter together so to stop the (slipping) which helps for fule econemy.
i found that in our tdci cars that this locks up very early and in all gears most of the time when possible. but at at lower speeds when taking off and as u described slow speeds 2nd gear it will not lock up which means the engine can rev higher to give more torque, this is what ur experiancing hope this helps mate.
There is nothing wrong with your box at all if this is whats happing

[marcusturbo]

thanks guys for clearing this up. what you have described helps me understand what the box is doing and now makes sense.

Least I can stop thinking that there is something wrong the box.

[obione980]

The lock up clutch on torque converters kicks in at higher speeds, not lower speeds - especially for highway cruising.

[fordmondeoman]

lock up clutches are much different these days than the old 4 speed autos which would only lock up in 4th when cruising. most if not all 6 speed autos will lock up in every gear including 1st and reverse, even when accelerating hard. they also can be pulsated on and off to control engine torque. If you have a chance to grab a scan tool and what what the lockup clutch is doing most people would be supprised as to how offen its locked up.
I know in the new 8 speed zf its locked up stright after take off even with full throttle, thats the advantage of 8 gears

[NZ XR6]

It's very obvious when it isn't locked, mostly at low revs on a light throtle. The Tiptronic mode is great - it's almost like a manual.

I've never noticed the Falcon 6-speed actually unlocking.