4L80e shifts harder when warm
#1
4L80e shifts harder when warm
To add to the list of issues with my newly built/installed 4L80E, it seems to increase shift firmness as it warms up. It is especially noticeable on the 1-2 shift. When cold (60-70F), the 1-2 is nice and crisp, when warm (90+F) the 1-2 is very firm and uncomfortable, this is under normal/light driving. I have modified the shift pressure tables to drop pressure when warm but it doesn't seem to help. Desired shift times are set to zero across the board. I do have some torque management for the 1-2 shift, it does seem to help soften the shift, but softens it at all temps, not just warm.
It's a 99 unit that I rebuilt with an HD2 shift kit, Sonnax boost valve, rollerized, and various billet parts and a full rebuilt kit. Also did the internal dual feed mod. I drilled the separator plate to "average" firmness for all gears.
Other issues that may or may not be related:
-No TCC lockup unless the line pressure is 150+psi
-Soft/delayed reverse engagement (I need to remove the reverse checkball)
-Very soft/slow 2-3 shift (I need to drill out the plate more or remove the 3rd checkball)
It's a 99 unit that I rebuilt with an HD2 shift kit, Sonnax boost valve, rollerized, and various billet parts and a full rebuilt kit. Also did the internal dual feed mod. I drilled the separator plate to "average" firmness for all gears.
Other issues that may or may not be related:
-No TCC lockup unless the line pressure is 150+psi
-Soft/delayed reverse engagement (I need to remove the reverse checkball)
-Very soft/slow 2-3 shift (I need to drill out the plate more or remove the 3rd checkball)
#7
I asked Chris about the spring a long time ago and he said he doesn't usually supply one unless it's a big power build looking to lockup at WOT. But that was in regards to a single-disk converter. I decided to go with a multi-disk, but he never asked me if I wanted the spring, I assumed it wasn't needed.
It won't lock even when I ground the solenoid, so it's an internal trans issue. If i command max pressure (~180psi in Drive) it will lockup no problem. If I'm at normal pressure and ground the solenoid nothing happens, but as I give it gas and the line pressure goes up the TCC will start to apply around ~130psi.
Last edited by Ferocity02; 05-01-2014 at 03:58 PM.
Trending Topics
#9
I'm having this same problem after my 80e swap. The 1-2 shift is ridiculously hard at light/normal throttle. It feels like it's going to brake something do I haven't driven it much. Is there something I could of done wrong in the swap or install of the HD2 kit?
Truck is a ecsb 4x4 6.0 BB tuned with a circle d 3k convertor.
Not trying to hijack your thread, I just figured this would be a good place to put it since I can't find answers anywhere else.
Thanks.
Truck is a ecsb 4x4 6.0 BB tuned with a circle d 3k convertor.
Not trying to hijack your thread, I just figured this would be a good place to put it since I can't find answers anywhere else.
Thanks.