4L70E Pump 1981, new and ready to install. Fits the 4L70E. Ships fast from the USA.
When a 4L70E, 4L65E, 4L60E or 700R4 pump is scored, noisy or losing pressure, swapping only the rotor rarely fixes it, because the slide, vanes and rings wear together. This kit replaces that whole rotating group at once. It is new and contains a 13-vane rotor, rotor guide, pump slide, 13 vanes, two hardened heavy-duty vane rings, an O-ring and a slide seal. The rotor is specified at .7060 to .7065 inch thick. You keep your own pump body and cover. The 1981 in the listing name reflects the first year of the GM pump family this design serves, not a 4L70E model year; the 4L70E name itself arrived much later.
The pump in the 4L60E family is a variable-displacement vane pump. The converter hub turns the rotor, the vanes ride against the inside of the slide, and the two vane rings keep the vanes pushed out against it at low speed. The slide pivots on a pin. Line pressure acting against the slide spring swings it toward less output once the transmission has enough oil, and back toward full output when demand rises. If the slide sticks, the pin wears or the rings and vanes lose their fit, output becomes weak or unstable and every apply circuit in the transmission feels it.
Low pressure also feeds the 4L70E's best-known failures, burned 3-4 clutches and TCC apply slip, so a worn pump is worth ruling out on any unit with those complaints.
Check fluid level and condition, then put a pressure gauge on it and watch for low or bouncing readings. Sonnax points out that a slide that binds can cause low pressure that otherwise seems unexplained, and that pulsation from poor pressure regulator valve control is the real threat to vane rings. With the pump on the bench, look for scoring in the pocket, a cracked rotor and a worn pivot pin. Our pump failure guide covers the full sequence, and the 3-4 clutch failure guide explains how pressure loss burns that clutch pack.
The kit is listed for 200-4R, 700R4 and 4L60, 4L60E, 4L65E, 4L70E and 4L75E, plus 4L40E, 5L40E and 5L50E, from 1981 onward, with exact fit varying by transmission. In practice it suits the late-model trucks and SUVs that carry the 4L70E, including Silverado, Sierra, Tahoe, Yukon and Trailblazer SS. Pump bodies differ by year, especially around the input speed sensor change, so check that your pump pocket and cover are reusable, and send us your year and VIN if you want us to confirm before ordering. See every part for this transmission in the 4L70E collection.
If you only need a rotor, the 13-vane rotor on its own is cheaper, and the billet 10-vane rotor suits builders converting to the 10-vane layout.
Most pumps are opened during an overhaul, so this kit pairs naturally with the 4L70E overhaul kit and a 1993-2014 shift kit to firm up pressure control.
| Fits | 4L70E 1981 |
| Part type | Pump |
| Condition | New |
| Brand | GM |
| Ships | From the USA |
| Warranty | 1-year |
No. It includes the 13-vane rotor, rotor guide, slide, 13 vanes, two vane rings, an O-ring and a slide seal. Your pump body and cover are reused.
No. 1981 is the start of the pump family the kit covers. It is listed for 200-4R and 700R4 through 4L60E, 4L65E, 4L70E and 4L75E, with fit varying by application.
There is no need. The kit replaces the vanes and both rings, and they should be replaced together with the rotor and slide so the clearances match.
Line pressure pulsation from a worn pressure regulator valve, air drawn in past the filter, a restricted filter and poor converter engagement are the common causes. Address them during the rebuild.
Use Dexron VI for 4L70E vehicles, as GM specifies. For older units, use the fluid listed in your owner manual.
