stormy_be
New Member
Well I suppose you have mistaken 4th gear with lock in 4th gear.
Count the real gear-changes to see if you really get to 4th.
Chosing lock is only done when warm, so that is normal.
When locking the gears, there is no "spin" anymore within the gearbox.
You can count on a rev-drop from 2500rpm to keep the speed of 90kmh, to 2000rpm with the same speed.
Regards, Koen
Count the real gear-changes to see if you really get to 4th.
Chosing lock is only done when warm, so that is normal.
When locking the gears, there is no "spin" anymore within the gearbox.
You can count on a rev-drop from 2500rpm to keep the speed of 90kmh, to 2000rpm with the same speed.
Regards, Koen
Thanks Koen
Not quite sure what you mean by lock? I am pretty sure that it stays in 3rd until its warmed up but I will check rpm before and after.
Cheers
Phil
thebiglad
Well-Known Member
Hi Phil, what Koen is referring to is "Torque converter (TC) lock-up"
In any autobox there is a device called a TC which is a bit like a clutch and it is this which allows the autobox to change gears and gives a certain amount of "slip".
However, above 52mph the TC 'locks up' giving, to all intents and purposes, the same feel as if you were in a manual box car in fifth gear, that's why the revs drop about 500rpm, as there is no more slip.
This is the correct functioning of this gearbox.
Cheers
Dave
PS You should be in 4th gear at about 35-40mph, on a light accelerator pedal load.
