Product Description
4L80-E, 4L85-E
Manual Valve Kit
Part No. 34994-16K
The OE manual valve in GM 4L80-E and 4L85-E transmissions is prone to bending due to its length and relatively narrow spools. Once bent, the valve causes excess bore wear, allowing critical fluid to escape the chosen circuits. This can result in delayed engagement, low line rise and loss of gear.
It is also common for the AFL filter and its end plug to leak, resulting in 2nd gear starts, no upshifts and various trouble codes. Installing improved Sonnax manual valve kit 34994-16K eliminates all these problems and renews AFL and manual circuit pressure control.
- Lengthened spools operate in non-worn portion of bore for added stability and wear prevention
- Stem diameter increased over OE
- O-ringed end plug positively seals bore to prevent leakage
- Hardcoat anodized aluminum valve combats premature wear
- Annular groove added to inboard spool to reduce side-loading
- Valve
- AFL Filter End Plug
- End Plug O-Ring
- AFL Filter O-Ring
Symptoms:
- Bent valves
- Low line rise
- Delayed engagement
- Gear loss
- Broken AFL filters
- Leaking AFL end plug
- 2nd Gear starts
- Code 68, 85, 86, 87
- No upshifts
