Transmission & Drivetrain Repair
Mondak's job is to determine where the power is being lost before we start removing major components.
If the Engine Is Making Power, We Find Out Where It Stops
Maybe the transmission shifts normally cold and starts acting up once it gets hot.
Maybe the machine goes into gear but barely moves under load. There is a driveline vibration. A differential is making noise. Or the transmission keeps setting a fault that comes back after it is cleared.
You already know what the equipment is doing.
Transmissions & Drivetrains We Work On
Mondak works across truck, vocational, industrial and off-highway powertrains including:
- Automatic transmissions
- Powershift transmissions
- Manual transmissions
- Automated manual transmissions
- Hydrostatic drive systems
- Torque converters
- Transfer cases and drop boxes
- Gearboxes
- Driveshafts and U-joints
- Axles
- Differentials
- Planetary drives
- Planetary wheel ends
- Final drives
- Clutches
- Electronic transmission controls
Common manufacturers include:
- Allison
- Eaton / Fuller
- Dana / Spicer
- ZF
- Funk / John Deere
- Meritor / Rockwell
- AxleTech
- Clark-Hurth and more
Allison Transmission Repair & Diagnostics
We see Allison transmissions across commercial trucks, vocational equipment, cranes, oilfield equipment and other heavy applications.
Common families include:
- Allison 1000 Series
- Allison 2000 Series
- Allison 3000 Series
- Allison 4000 Series
- Older Allison vocational and industrial transmissions
Mondak also has Allison DOC diagnostic capability for applicable electronically controlled transmissions.
That allows us to look at information such as:
- Transmission fault codes
- Input and output speeds
- Gear commands
- Clutch information
- Temperature
- Engine and throttle data
- Solenoid operation
- Communication faults
- Inputs and outputs
A transmission code does not automatically mean the transmission needs to come out.
Eaton / Fuller
Heavy trucks still use a wide range of Eaton and Fuller transmissions.
That includes current and legacy platforms such as:
- 8-speed
- 9-speed
- 10-speed
- 13-speed
- 15-speed
- 18-speed
- 8LL
- AutoShift
- UltraShift
- UltraShift PLUS
- Fuller Advantage
- Endurant
On an automated transmission, the mechanical transmission may be fine.
The problem may instead involve:
- Clutch actuator
- Shift actuator
- Sensors
- Wiring
- Controller
- CAN/J1939 communication
- Engine torque information
- Brake or neutral interlocks
That is why we diagnose the controls before blaming the gearbox.
Off-Highway Powershift Transmissions
A loader, crane, railmover or industrial machine has a different drivetrain than a highway truck.
Mondak works with off-highway systems from manufacturers including:
- ZF
- Dana / Spicer
- Funk / John Deere
- Clark-Hurth
- AxleTech and other industrial platforms
These systems may involve:
- Powershift clutch packs
- Torque converters
- Hydraulic control pressure
- Transmission pumps
- Solenoids
- Control valves
- Transmission controllers
- Speed sensors
- Planetary reductions
- Electronic shift controls
It Works Cold. Then Something Changes.
Temperature can tell us a lot.
A transmission that performs normally cold but starts slipping, shifting differently or losing drive after warming up gives us different information than one that will not move at all.
Depending on the system, we may test:
- Transmission oil pressure
- Clutch pressure
- Converter performance
- Internal leakage
- Oil condition
- Filter restriction
- Temperature
- Solenoid operation
- Speed-sensor data
- Electronic commands
- Mechanical wear
Hot, cold, empty and loaded are diagnostic information.
Torque Converters
A machine that feels weak does not automatically have an engine problem.
Torque converter problems can show up as:
- Poor acceleration
- Weak pushing or pulling power
- Excessive heat
- High engine speed with poor machine response
- Changed stall characteristics
- Contaminated oil
- Lockup problems where equipped
The engine may be producing the power.
The converter may not be transferring it.
Axles, Differentials & Final Drives
Transmission repair is only part of the powertrain.
Mondak also works with problems involving:
- Steer axles
- Drive axles
- Tandem axles
- Differentials
- Ring and pinion sets
- Axle shafts
- Planetary hubs
- Wheel ends
- Final drives
- Drop boxes
- Transfer cases
- Drivelines and driveshafts
Noise, heat, metal in the oil, excessive play or a machine that pulls differently than it should can all point farther downstream than the transmission.
AxleTech & Heavy Off-Highway Axles
Mondak also works with AxleTech axle and drivetrain components found in heavy off-highway and specialty equipment.
That can include:
- Planetary drive axles
- Steerable planetary axles
- Tandem axles
- Planetary wheel ends
- Differentials
- Hubs
- Brakes
- Shafts
- Related drivetrain components
AxleTech assemblies show up in applications where ordinary highway axles are not enough: heavy construction equipment, industrial machines, specialty vehicles and severe-duty equipment.
And on older machines, identifying the axle can become part of the job.
The original machine model may not tell us everything we need.
We may need:
- Axle identification tags
- Casting numbers
- Gear ratio
- Shaft configuration
- Brake configuration
- Hub or planetary information
We identify what is actually under the machine before ordering parts.
Meritor, Rockwell & Legacy Drivetrain Components
Older equipment may carry names such as:
- Rockwell
- Meritor
- AxleTech
- Spicer
- Clark
- Clark-Hurth
- Funk
Some of those product lines have changed ownership or branding several times since the machine was built.
That does not change the component physically installed.
For older equipment, tags, casting numbers, ratios and internal configuration can matter more than the current name on the parts catalog.
Electronic Transmission Problems
Modern powertrains depend heavily on electronics.
A machine that refuses to shift may have an internal transmission problem.
It may also involve:
- Speed sensors
- Shift solenoids
- Clutch actuators
- Transmission controllers
- Wiring
- Connectors
- Power and grounds
- CAN/J1939 communication
- Engine torque information
- Brake or neutral interlocks
Mondak's OEM diagnostic capabilities allow us to follow problems between the engine, transmission, chassis and equipment controls.
Sometimes the transmission is being blamed for doing exactly what another controller told it to do.
When the Transmission Really Has Failed
Sometimes the testing confirms the major component is the problem.
Mondak can handle work involving:
- Transmission removal and installation
- Major transmission repair
- Torque converter replacement
- Clutch work
- Driveline repair
- Differential repair
- Axle repair
- Planetary and wheel-end repair
- Transfer case and gearbox work
- Final-drive work
- Component replacement
- Related machining and fabrication
The right repair depends on the machine, component condition, parts availability and what makes economic sense.
Obsolete & Hard-to-Find Drivetrain Parts
Older powertrain components can be extremely difficult to support.
A transmission, axle, differential or gearbox may still be repairable except for one component that is:
- Obsolete
- No longer manufactured
- Available only used
- Superseded without a direct replacement
- Difficult to identify
- Unsupported by the original manufacturer
Mondak can look beyond simply ordering the original part number.
Depending on the problem, that may involve:
- Repairing the original component
- Cross-referencing a replacement
- Sourcing rebuilt components
- Machining parts
- Making shafts, bushings or spacers
- Fabricating mounts
- Adapting a newer assembly
- Updating controls where practical
Finding what failed is sometimes only half the repair. The other half is figuring out what to do when the original part no longer exists.
Field Diagnosis Before the Major Component Comes Out
A transmission or axle problem does not automatically mean the first step is hauling the entire machine into the shop.
Mondak can perform field diagnostics to help determine whether the problem is actually inside the transmission, axle or drivetrain before major disassembly begins.
When the component needs to come out, our field service is backed by shop capabilities for repair, machining and fabrication.
Tell Us What Happens Under Load
Whether it will not move, shifts differently hot, slips under load, has a driveline vibration or already has a known axle or transmission failure, you do not need to diagnose it before calling.
If you have the transmission, axle or component model and serial number, bring it.
Tell us the machine, drivetrain information and what it is doing. We'll start there.