Product Description
Fits: 4L80-E / 4L85-E
Sonnax manual valve kit 34994-16K for GM 4L80-E and 4L85-E transmissions. It replaces the bend-prone OE manual valve and the AFL filter end plug and seals, renewing AFL and manual circuit pressure control.
Specifications
| Fits | 4L80E |
|---|---|
| Sonnax part number | 34994-16K |
| Material | Hardcoat anodized aluminum valve |
Why it fails
The OE manual valve is long, with relatively narrow spools and minimal valve support. It is prone to bending, and a bent valve causes excess bore wear that lets fluid escape the selected circuits, causing delayed engagement, low line rise and loss of gear.
The AFL filter and its end plug also commonly leak, causing 2nd gear starts, no upshifts and trouble codes. Symptoms covered by this kit: bent valves, low line rise, delayed engagement, gear loss, broken AFL filters, leaking AFL end plug, 2nd gear starts, codes 68, 85, 86 and 87, and no upshifts.
The Sonnax valve has lengthened spools that ride in the unworn part of the bore, a larger stem diameter than OE, hardcoat anodized aluminum construction and an annular groove on the inboard spool to reduce side-loading. The O-ringed end plug seals the bore to prevent leakage.
What's included
- Valve
- AFL filter end plug
- End plug O-ring
- AFL filter O-ring
