P0730 on RAM: How to Diagnose & Fix
Incorrect Gear Ratio
1 RAM model · 1 documented issue · $300-$3,500 repair
P0730 on RAM by model: symptoms, diagnosis and fix
RAM 1500s with the ZF-based 8-speed automatic (TorqueFlite 845RE / 850RE, 8HP70/8HP75) commonly develop torque-converter clutch shudder. It feels like a slight-to-heavy vibration or 'driving over rumble strips' at part throttle and light acceleration, typically 15-50 mph as the converter approaches lock-up. Owners frequently report it around the 70,000-80,000 mile range, often tied to degraded fluid friction-modifier and/or worn/glazed torque-converter clutch material. Severe cases drop into limp mode (stuck in a single gear, often reported as 4th, with a CEL). Harsh 1-2/2-3 upshifts are also reported and are often resolved by a TCM software reflash.
Common Symptoms
- Vibration/shudder at light throttle, ~15-50 mph, near converter lock-up
- Harsh or clunky 1-2 and 2-3 upshifts
- Burnt-smelling or dark transmission fluid
- Limp mode (stuck in one gear) with check engine light
How to Fix
First request all available TCM/transmission software updates (multiple TSBs/reflashes exist). A full fluid-and-filter service with the correct ZF spec fluid resolves a large share of early shudder cases. Persistent shudder after fluid/software typically requires torque-converter replacement or rebuild. Stellantis specifies long fluid intervals, but many owners service the fluid by ~60k miles preventively.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Genuine Mopar 68218925AB 8 & 9 Speed ATF, one quart
Mopar 68218925AB fluid for applicable 8- and 9-speed units; verify the owner's/service information and required quantity for the exact transmission.
- Genuine Mopar 68225344AA 8HP70/8HP75 pan and integrated filter
Confirm VIN, engine and transmission sales code. Do not use for the 3.6L 845RE/850RE branch.
- Genuine Mopar 52854834AB 845RE/850RE pan and integrated filter
2018-2025 Ram 1500 3.6L applications shown by the OE catalog, including 845RE/850RE variants; confirm VIN and transmission code.
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Sources for this issue (5)
- FCA TSB 21-064-15: Flash: 8HP70 Transmission Shift Enhancements (2015 DS RAM 1500 5.7L)tsb
- TSB 21-014-15: Flash: 8HP70 Transmission Shift Quality and Drivability Enhancementstsb
- ZF 8HP (845RE/850RE/8HP75/8HP95) Transmission Problems, Symptoms & Fixes (DK Transmission)article
- Transmission - Torque Converter Slip / Shutter (RAM 1500 Diesel Forum)forum
- 8 SPD Transmission Shudder (RamForumZ)forum
P0730 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0730 mean on a RAM?
P0730 stands for "Incorrect Gear Ratio." This code means the transmission computer detected that the actual gear ratio (calculated from input vs. output shaft speeds) does not match what it should be for the commanded gear. In other words, the transmission isn't delivering the correct gear, which often shows up as slipping, flaring RPM during shifts, or being stuck in the wrong gear. It can stem from internal mechanical wear, low or contaminated fluid, or faulty solenoids and sensors. The vehicle may shift harshly or enter limp mode. On RAM it is documented across 1 model: 1500.
What are the most common causes of P0730?
The most common causes of P0730 are: Low or contaminated transmission fluid, Worn clutches or bands (internal slipping), Faulty shift solenoids, Dirty or sticking valve body, Faulty input or output speed sensor, Internal hydraulic/line pressure problems, Torque converter problems, General high-mileage transmission wear. The specific cause varies by vehicle.
How much does it cost to fix P0730 on a RAM?
Published repair estimates on RAM range from $300 to $3,500 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.