The 68RFE valve body wear is the #1 issue on 2007.5+ Dodge Cummins trucks. Symptoms range from harsh shifts to total trans failure. Sonnax has the fix - here is how to apply it.
Why the 68RFE valve body wears
Aluminum body, aluminum bore:
- Valves slide in soft material
- Galling under high pressure
- Wear accelerates over time
High line pressure:
Heat exposure:
Symptoms by valve body section
Pressure regulator valve worn:
- Low line pressure
- Soft shifts
- Slip under load
- Eventually clutch wear
TCC regulator valve worn:
Switch valve worn:
Solenoid switch valve:
Diagnosis
Step 1: Pressure test
- Line pressure: 95-180 PSI by gear
- Low across board = pump or PR valve
- Specific gear low = section-specific valve
Step 2: Pull DTCs
- P0700 + P0741 = TCC regulator
- P0700 + multiple shift = switch valves
- P0700 + slip codes = PR valve
Step 3: Drop pan
- Aluminum chips in pan = valve body wear confirmed
- Steel chips = bigger problem (clutches)
- Burnt fluid = both
Sonnax fix kits
Sonnax pressure regulator kit:
Sonnax TCC regulator kit:
Sonnax switch valve kits:
Sonnax full valve body rebuild kit:
Install requirements
Reamer tool required:
- Bore must be reamed before sleeve install
- Specific Sonnax reamer per valve
- $100-$300 per reamer
- Rent from rebuilders or buy
Press fit sleeves:
Reassembly:
Cost
DIY single valve kit:
DIY full VB kit:
Shop installation:
Shop valve body exchange:
When valve body is not enough
If line pressure still low:
If TCC shudder persists:
If multiple gear codes:
HD upgrade considerations
If tuned truck:
If towing trailer:
Cost of NOT fixing valve body
Within 20k miles:
Within 50k miles:
Vs early fix:
Bottom line
68RFE valve body wear is universal:
Sonnax kits work:
Need 68RFE valve body kits, HD parts, or rebuild bundles? Visit our 68RFE catalog. Sonnax kits, complete valve bodies, full rebuild kits. Free shipping over $70.
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