1986 toyota 4runner problems

blazerbrad · 07-27-2010, 08:28 AM

A lot of automatics will shift into 2nd even if you have the shifter in 1st. My '03 Chevy 2500HD with the electronically controlled 4L80E will do this even at part throttle once you get to a certain speed, and my '90 K5 Blazer with a fully hydraulic 700r4 will shift to 2nd if you hit redline.

It's a fail safe to keep you from over-revving the engine. They can prevent this when you are using the throttle by a simple rev limiter or governor on the engine, but if you do something like shift to 1st and go down a steep grade the wheel speed could cause the engine to over speed.

07-27-2010, 08:28 AM	#6
blazerbrad - CORE Member - Join Date: Feb 2007 Posts: 831 Images: 6	A lot of automatics will shift into 2nd even if you have the shifter in 1st. My '03 Chevy 2500HD with the electronically controlled 4L80E will do this even at part throttle once you get to a certain speed, and my '90 K5 Blazer with a fully hydraulic 700r4 will shift to 2nd if you hit redline. It's a fail safe to keep you from over-revving the engine. They can prevent this when you are using the throttle by a simple rev limiter or governor on the engine, but if you do something like shift to 1st and go down a steep grade the wheel speed could cause the engine to over speed.