1st to 2nd shift slipping at WOT

[Mayhem]

I have a 4l65e in a 4x4 Nissan with LS6 running 36' tires and 4.33 ratios and am busy tuning the motor (SD) My problem is that when it changes from 1st to 2nd with my foot down hard the box changes but I get a burnt clutch smell for a second or two. I have reduced shift time and upped the pressure but it still slips when changing gear. Under normal driving conditions it changes with no problem. Is this a tuning problem or can the 4l65e just not handle the torque with the large tires?

[joecar]

The large tires may possibly be causing the problem...

you will need to add in Torque Reduction (see D0801);

there may be other problems, like insufficient line pressure, or an internal hydraulic circuit leak, or insufficient 2nd servo piston area, or inappropriate band.

How much FWTQ are you making...?

[Mayhem]

The large tires may possibly be causing the problem...

you will need to add in Torque Reduction (see D0801);

there may be other problems, like insufficient line pressure, or an internal hydraulic circuit leak, or insufficient 2nd servo piston area, or inappropriate band.

How much FWTQ are you making...?

Hi Joecar
I havent got it onto a dyno yet. I'm trying to get as mush tuning done on the road so as to not spend to much time on the dyno. I don't suspect the box having a problem but you never know. Could I have already damaged it by having it slip about 3 or 4 times? I am now awear of the problem so am not doing this change at WOT now.

[joecar]

3 or 4 times won't have caused damage.

[Mayhem]

Thanks Joecar, I hope not. I will monitor it.

[joecar]

You can log TFMPRS (to see if commanded pressure dips low during shift) and SHIFTLAST (to see the shift duration time).