LS swap transmission problems

[jack1985]

I finished Ls swap into my 85C10. I keep getting code P0740. I have already changed filter and modules in transmission. Trans shifts fine but do hear whining when driving, do I need to change torque conveter?

 

[Bextreme04]

I finished Ls swap into my 85C10. I keep getting code P0740. I have already changed filter and modules in transmission. Trans shifts fine but do hear whining when driving, do I need to change torque conveter?

What transmission did you put in? What engine? What controller? Did you use the factory harness or an aftermarket one?

 

[Matt69olds]

PO740 is a converter slippage code. Meaning the pcm is commanding the TCC to apply, but it either isn’t or it’s slipping

Can you feel the converter engage? Get it up to highway speed, stay steady on the throttle and touch the brake pedal. Not enough to actually slow the truck, just enough to turn on the brake lights. You should hear and feel the engine rev a couple hundred rpm.

The 4L60e are notorious for wearing out the TCC valve in the valve body. TransGo offers a couple shift kits that solves the problem. If it checks out electrically, and the converter clutch isn’t burned up the shift kit might solve the problem.

 

[jack1985]

I put a 2007 5.3 with a 4l60 into my 1985 C10

 

[TotalyHucked]

How many miles on the engine/trans? Any mods, like a camshaft/etc? Factory computer or something like a Holley setup?