The manual transmission in your 2020 Wrangler offers the engagement that enthusiasts love. When grinding appears during shifts, something isn't synchronizing properly—either the clutch isn't fully disengaging or internal synchronizers are worn.
The NSG370 Transmission
The 2020 Wrangler uses the NSG370 6-speed manual, a German-designed transmission known for:
- Precise, short throws
- Durable construction for off-road use
- Synchronized reverse gear
Grinding Scenarios
Grinding into all gears:
- Clutch not fully disengaging
- Low clutch fluid or air in system
- Clutch hydraulic failure
Grinding into specific gears:
- Synchronizer wear for those gears
- 2nd and 3rd most common
Grinding only when cold:
- Transmission fluid viscosity issue
- Synchro wear more apparent when cold
Common Causes
- Clutch hydraulic issue - Air or low fluid
- Worn clutch - Not fully releasing
- Synchronizer wear - Can't match speeds
- Wrong fluid - NSG370 requires specific fluid
- Shift linkage wear - Prevents complete engagement
Diagnostic Steps
- Check clutch fluid level in reservoir
- Try shifting with engine off—if smooth, clutch is likely issue
- Note which specific gears grind
- Does double-clutching eliminate grinding?
- Check transmission fluid level and type
NSG370 Fluid Requirement
The NSG370 requires specific Mopar transmission fluid. Using incorrect fluid causes shifting issues and accelerates synchronizer wear.
Repair Costs
- Clutch fluid bleed: $75-$150
- Transmission fluid service: $100-$200
- Clutch replacement: $1,000-$2,000
- Synchronizer rebuild: $1,500-$3,000
- Transmission replacement: $3,000-$5,000