How does the 4L80 transmission control work?
The 4L80E transmission may feature two speed sensors, one for turbine input speed and one for output speed. It uses the Input Speed Sensor to monitor input speeds to compare against engine speed and output Shaft Sensor speed, using this data to adjust shift speeds under instantly detectable conditions.
What does 4L80E stand for?
The 4L80-E (and similar 4L85-E) was a series of automatic transmissions from General Motors. Designed for longitudinal engine configurations, the series included 4 forward gears. It was an evolution of the Turbo-Hydramatic 400, first produced in October 1963.
What do you need to know about GM 4L80E transmission?
Because the 4L80 transmissions are sometimes used in conversion applications with earlier, non-PCM controlled engines, GM and aftermarket control modules are required and used to control the operation of the transmission in these scenarios. The 4L80E transmission may feature two speed sensors, one for turbine input speed and one for output speed.
When did the GMC 4L85 transmission come out?
The 4L85 transmission was introduced in 2002. Some of the differences included a 5-pinion output gearset and 5-pinion reaction gearset. Though not a transmission development change, in 2006 GM specified a new transmission fluid formulation and required its use (for warranty) in the 4L80 series.
When to replace shift solenoids in GM 4L60-E?
TIP 4: If your transmission is slipping, replacing the shift solenoids, even if they’re fried will not solve the slipping issue. The 4L60-E transmissions uses several solenoids and sensors to control/activate its 4 gears.
Is the GM 700R4 a heavy duty transmission?
The 700R4 was a pretty tough transmission, but not quite in the class of the TH400. GM needed a heavy-duty automatic overdrive. GM used as many TH400 parts and designs as possible in the 4L80E, but the added overdrive gear would require an extra gearset and slightly longer (~1-1/2″) case.
Because the 4L80 transmissions are sometimes used in conversion applications with earlier, non-PCM controlled engines, GM and aftermarket control modules are required and used to control the operation of the transmission in these scenarios. The 4L80E transmission may feature two speed sensors, one for turbine input speed and one for output speed.
The 4L85 transmission was introduced in 2002. Some of the differences included a 5-pinion output gearset and 5-pinion reaction gearset. Though not a transmission development change, in 2006 GM specified a new transmission fluid formulation and required its use (for warranty) in the 4L80 series.
Why do I have bad shifting on my 4L80E?
In addition to erratic shifting, the trans control program will default to backup shifting mode if you drive it long enough with this bad sensor, and as a result line pressure through the valve body will be boosted to maximum value, creating harsh shifting.
The 700R4 was a pretty tough transmission, but not quite in the class of the TH400. GM needed a heavy-duty automatic overdrive. GM used as many TH400 parts and designs as possible in the 4L80E, but the added overdrive gear would require an extra gearset and slightly longer (~1-1/2″) case.