Eaton Fuller 18-Speed Transmission for Sale | OEM Used RTLO-18918 / RTLO-22918 Roadranger | Class 8 Heavy-Duty Manual
$5,250.00
At a Glance
- Condition: OEM used, all 18 forward gears and reverse function tested
- Availability: In stock, Eaton Fuller 18-speed transmissions available
- Shipping: Free shipping to all 50 states via freight pallet, 5 to 10 business days
- Model designation confirmed (RTLO-18918 vs RTLO-22918)
- Donor truck confirmed (Freightliner, Kenworth, Peterbilt, Volvo, Mack, International)
- Engine pairing confirmed (Cummins, Detroit, PACCAR, CAT, Volvo, Mack)
- All 18 forward gears and reverse tested
- Splitter function verified (air-actuated)
- Range selector verified (air-actuated)
- Clutch brake and bell housing bolt pattern confirmed
- Yoke and output shaft spline count verified
- 100% inspection before every order ships
- No core charge required
- Backed by a 15 day replacement warranty against internal defects
Description
About the Eaton Fuller 18-Speed Transmission
The Eaton 18-speed transmission is the most respected manual transmission in heavy-duty Class 8 trucking, where flexibility and endurance are critical characteristics. It has many gears, allowing the driver to easily move from low-speed launch torque on steep grades and heavy loads to smooth overdrive cruising at highway speeds. This Eaton 18-speed Transmission for Sale at Part Nests is a manual transmission that requires skilled clutch and shifter coordination, demanding driver expertise but delivering exceptional control over power delivery and durability. This makes the Eaton 18-speed the most preferred transmission for owner-operators and fleet managers who prioritize reliability, longevity, and the maximum mechanical efficiency of a direct manual driveline.
The Eaton Fuller Heavy-Duty Manual Family
The Eaton Fuller heavy-duty manual transmission family includes multiple configurations for different Class 8 applications. The RTLO-18918 / RTLO-22918 18-speed (this listing) is the dominant long-haul Class 8 highway transmission, with closer ratio spacing for highway use. For vocational, severe-duty, construction, logging, mining, and heavy-haul applications requiring deep-reduction low gears, see our vaz131 listing (Eaton Fuller 8LL 8-speed manual with Low-Low deep reduction split, 12.64:1 first gear). The 18-speed and 8LL are different transmissions optimized for different duty cycles; the 18-speed is the highway choice, the 8LL is the vocational / severe-duty choice.
Why Choose an Eaton 18-Speed Transmission
- Wide Range of Gear Ratios: From the deep-reduction low range (1st gear 14.66:1) for heavy starts on steep grades to the overdrive ratios (9th gear 3.42:1) for fuel-efficient highway cruising. The 18-speed lets you keep the engine in its narrow peak-torque band regardless of load or grade.
- Splitter and Range Shifts: Enables precise gear selection with air-actuated splitter (low/high within each main gear) and range shifts (low range / high range), optimizing power delivery and engine efficiency.
- Manual Operation: Requires skilled clutch control for smooth gear transitions, enhancing driver control and adaptability in challenging conditions.
- Durability: Built to withstand heavy Class 8 loads (80,000-plus lbs GCW) and demanding duty cycles, ensuring long-term reliability and reduced maintenance costs across high mileage.
- Enhanced Fuel Efficiency: Through versatile gear ratios and efficient direct mechanical power delivery, the transmission helps improve fuel economy by allowing the engine to operate at its most efficient RPM range across varying conditions.
Innovative and Patented Design
You might want this Eaton 18-speed transmission not just because you need one, but also because of the proven design elements that contribute to its performance and reliability:
- Precision Gear Design: State-of-the-art gear tooth configuration and material technology guarantee seamless engagement, longevity, and the ability to handle high-torque Class 8 diesel inputs.
- Splitter Mechanism: The patented Eaton splitter design splits each main gear into low and high, doubling the effective gear count and allowing precision RPM management across the operating range.
- Shift Quality and Control: Shift control technologies include synchronizer-free engagement (with the famous Eaton “double-clutching” or “float-shifting” technique), air-actuated splitter control on the shift knob, and air-actuated range selector. These reduce driver fatigue on long hauls.
- Efficiency Enhancements: Improved bearing arrangements, reduced internal friction, and twin-countershaft architecture distribute torque loading and improve overall mechanical efficiency.
- Durability Enhancements: Reinforced material in high-stress areas allows the unit to handle the heaviest loads in commercial trucking, including specialized heavy-haul applications.
Eaton 18-Speed Transmission Fits
Vehicles (Class 8 Tractors and Vocational Trucks):
- Freightliner: Cascadia, Coronado, Classic XL, Argosy (older)
- Kenworth: T680, T880, W990, W900 (older)
- Peterbilt: 579, 389, 567, 386 (older)
- Volvo: VNL series (long-haul), VNR (regional), VHD (vocational)
- Mack: Anthem, Pinnacle, Granite (vocational)
- International: LT Series, HX Series, ProStar (older)
- Western Star: 4900, 5700XE, 5700, 4700 (some applications)
Compatible Engines (Class 8 Diesel):
- Cummins: ISX15, X15, ISM, L9, M11 (older)
- Detroit Diesel: DD13, DD15, DD16, Series 60 (older)
- PACCAR: MX-13, MX-11
- Caterpillar: C15 (our vaz85 listing), C16 (older models, Cat exited on-highway in 2010)
- Volvo: D13 (our vaz120 listing), D16
- Mack: MP7, MP8, MP10
Quality Assurance
When you purchase a used Eaton 18-speed transmission from Part Nests, you can rest assured that you are getting a quality product. Our process includes:
- Thorough inspection of all 18 forward gears and reverse
- Rigorous testing through both splitter and range positions
- Air system function verification
- External case visual inspection for cracks or weld repairs
Why Choose Our Used Eaton 18-Speed Transmissions
- Thoroughly inspected with model designation confirmed (RTLO-18918 vs RTLO-22918)
- Competitive pricing vs Eaton dealer reman
- Expert technical support for installation questions
- Donor truck identification documented
Vehicle Compatibility
| Vehicle | Compatibility |
|---|---|
| Freightliner Class 8 | Cascadia, Coronado, Classic XL |
| Kenworth Class 8 | T680, T880, W990, W900 |
| Peterbilt Class 8 | 579, 389, 567 |
| Volvo Trucks | VNL, VNR, VHD |
| Mack Trucks | Anthem, Pinnacle, Granite |
| International | LT Series, HX Series, ProStar |
| Western Star | 4900, 5700XE |
| Vocational | Construction trucks, heavy-haul, refuse, vocational |
Inspection Workflow
- Model designation confirmed (RTLO-18918 vs RTLO-22918)
- Torque rating documented (1,800 vs 2,250 lb-ft)
- Donor truck confirmed (Freightliner, Kenworth, Peterbilt, Volvo, Mack, International)
- Engine pairing confirmed
- All 18 forward gears tested through both splitter (high/low within each main) and range (low/high range) positions
- Reverse tested in both low and high range
- Splitter air valve function verified
- Range selector air valve function verified
- Clutch brake function verified
- Bell housing bolt pattern confirmed
- Output yoke and spline count verified
Why Buy From Part Nests
- Model designation confirmed (RTLO-18918 / RTLO-22918)
- Donor truck and engine pairing confirmed
- All 18 forward gears and reverse tested
- Splitter and range air system verified
- Clutch hardware compatibility noted
- Free freight pallet delivery to all 50 states
- 15 day replacement warranty on internal defects
- Class 8 heavy-duty experienced support team
- Call (855) 634-4447 to confirm model designation (RTLO-18918 1,800 lb-ft vs RTLO-22918 2,250 lb-ft), donor Class 8 truck, engine pairing (Cummins, Detroit, PACCAR, Cat C15 per vaz85, Volvo D13 per vaz120, Mack), and Eaton family questions (18-speed Roadranger highway transmission per this listing vs 8LL vocational / severe-duty per vaz131) before ordering
15 Day Replacement Warranty
Every used Eaton Fuller 18-speed RTLO transmission purchased through Part Nests carries a 15 day replacement warranty starting on the delivery date.
What Is Covered
- Internal defects already present when the transmission arrives
- Gear or shaft failures within 15 days from installation
- Loss of any of the 18 forward gears or reverse within 15 days from installation
- Splitter air valve failures within 15 days from installation
- Range selector air valve failures within 15 days from installation
- Internal bearing failures within 15 days from installation
- Case crack failures not disclosed at shipping
- Incorrect model designation shipped (RTLO-18918 1,800 lb-ft vs RTLO-22918 2,250 lb-ft) due to an error on our end
What Is Not Covered
- Damage caused during installation
- Damage from operating with incorrect gear oil (use Eaton-approved synthetic transmission lubricant only; consult Eaton spec sheet for your model)
- Damage from neglected fluid maintenance
- Damage from operating beyond the torque rating (1,800 lb-ft for RTLO-18918; 2,250 lb-ft for RTLO-22918; aggressive aftermarket engine tuning beyond these ratings stresses the transmission beyond its design limits)
- Damage from incorrect clutch hardware or pilot bearing
- Damage from operating with low or contaminated air supply (the splitter and range systems require clean dry compressed air per Eaton specifications)
- Damage from incorrect bell housing alignment or clutch brake adjustment
- External components (driveshaft, transmission mount, shift lever, air lines and valves, clutch hardware, flywheel) unless itemized
- Labor expenses of any kind
To start a warranty claim, reach us within 15 days of delivery at (855) 634-4447.
- Model Designation Confirmed: RTLO-18918 (1,800 lb-ft) or RTLO-22918 (2,250 lb-ft) documented
- All 18 Forward Gears Tested: Through both splitter and range positions, plus reverse
- Air System Verified: Splitter and range selector air valve operation confirmed
- Donor Truck and Engine Pairing Confirmed: Cummins, Detroit, PACCAR, Cat, Volvo, or Mack engine documented
- Bell Housing and Output Spline Verified: Clutch and driveshaft compatibility confirmed
- 15 Day Replacement Cover: Internal defects protected from delivery onward
Additional information
| bellhousing-to-tailshaft-length | 38 to 42 inches |
|---|---|
| fluid-capacity | 36 to 40 quarts |
| gear-ratios | Low Range (Deep Reduction): 1st 14.66, 2nd 12.21, 3rd 10.12. High Range: 4th 8.41, 5th 7.02, 6th 5.86. Overdrive: 7th 4.89, 8th 4.10, 9th 3.42. Reverse: Low 16.55, High 13.87 |
| overall-length | 47 to 50 inches |
| torque-rating | 1, 450 lb-ft to over 2, 050 lb-ft |
| weight | 700 to 800 pounds |
| type | Heavy-Duty Truck Transmission |
Torque rating. The Eaton Fuller RTLO-18918 is rated for 1,800 lb-ft of input torque; the RTLO-22918 is rated for 2,250 lb-ft. The two share the same fundamental architecture (twin-countershaft, 18 forward gears via 9 main gears x 2 splitter positions, air-actuated splitter and range selector) but differ in internal hard parts spec, gear material strength, and bearing capacity. The RTLO-18918 is appropriate for typical line-haul Class 8 applications with engines producing up to 1,800 lb-ft. The RTLO-22918 is appropriate for higher-torque applications including the Cummins ISX/X15 high-output, Detroit DD15/DD16 high-torque, Cat C15 high-output (our vaz85 listing), and Volvo D13 high-output (our vaz120 listing) and is generally preferred for heavy-haul / oversize-load specialty applications. We confirm the model designation on every order.
Air-actuated 2x doubling of effective gear count. The Eaton 18-speed produces 18 forward gears from 9 main gear positions via two independent air-actuated mechanisms. The splitter (controlled by an air valve on the shift knob) splits each main gear into low and high positions, effectively doubling the gear count from 9 to 18. The range selector (controlled by an air valve typically below the shift knob) shifts the entire gearset between low range and high range, doubling the effective gear count again. Combined, the driver has access to 18 forward gears that can be selected by combinations of shifter position, splitter button, and range selector. The system is patented Eaton design and is the heart of why the 18-speed is the dominant Class 8 manual transmission.
Synchronizer-free shifting that experienced drivers prefer. The Eaton heavy-duty manual transmissions (including the 18-speed RTLO and the 8LL per our vaz131 listing) are constructed without synchronizers on the main gear engagement. This makes them more durable than synchromesh transmissions but also requires the driver to learn one of two shifting techniques: traditional double-clutching (pressing the clutch twice for each shift, once into neutral and once into the new gear), or float-shifting (matching engine RPM to road speed precisely and shifting without the clutch, only using the clutch for stopping and starting). Float-shifting is the technique experienced Class 8 drivers prefer for highway operation; it reduces driver fatigue, extends clutch life, and produces faster shifts. Learning float-shifting takes practice; double-clutching is the alternative.
Class 8 diesel engines across all major manufacturers. The Eaton 18-speed Roadranger is pairs with virtually every Class 8 diesel produced in the modern era: Cummins ISX15, X15, ISM, L9, M11 (older); Detroit Diesel DD13, DD15, DD16, Series 60 (older); PACCAR MX-13, MX-11; Caterpillar C15 (our vaz85 listing), C16 (older models; Cat exited on-highway truck engines in 2010); Volvo D13 (our vaz120 listing), D16; Mack MP7, MP8, MP10. The bell housing bolt pattern is the standard SAE #1 Class 8 pattern that all major manufacturers use. We confirm the engine pairing on every order; the engine determines the appropriate torque rating (RTLO-18918 vs RTLO-22918) and bell housing pattern variant.
All major Class 8 conventional cab tractors and many vocational chassis. The 18-speed Roadranger is the standard manual transmission across the modern Class 8 lineup: Freightliner Cascadia, Coronado, Classic XL, Argosy (older); Kenworth T680, T880, W990, W900 (older); Peterbilt 579, 389, 567, 386 (older); Volvo VNL series long-haul, VNR regional, VHD vocational; Mack Anthem, Pinnacle, Granite vocational; International LT Series, HX Series, ProStar (older); Western Star 4900, 5700XE, 5700, 4700. Vocational applications including construction trucks, heavy-haul, refuse, and specialty hauling are also compatible. Confirm chassis manufacturer and model when ordering.
Highway use vs vocational / severe-duty. The 18-speed Roadranger (this listing) is optimized for long-haul highway use, with closer ratio spacing for smooth shifts at sustained highway speeds and an overdrive 9th gear (3.42:1) for fuel-efficient cruising. The 8LL (our vaz131 listing) is optimized for vocational and severe-duty use (construction, logging, mining, heavy-haul, refuse), with a deep-reduction Low-Low 1st gear (12.64:1) for heavy starts on steep grades. The 18-speed has more total gears (18 vs 8) but the 8LL has the deeper Low Range that some vocational operations require. Highway fleet owner-operators typically choose the 18-speed; vocational operators (concrete mixers, dump trucks, logging trucks, mining haulers) typically choose the 8LL.
Stops countershaft for clean start engagement. The clutch brake is a small friction disk on the transmission input shaft, located inside the bell housing. When the driver pushes the clutch pedal all the way to the floor (past the normal clutch disengagement point), the clutch brake engages and stops the rotation of the transmission input shaft. This allows clean engagement of the starting gear (typically 1st low or 2nd low on the 18-speed) without grinding. The clutch brake is required for starting from a stop in a non-synchronized heavy-duty manual; once moving, float-shifting or double-clutching is used for all subsequent gear changes. The clutch brake is a wear item that should be inspected and adjusted at clutch replacement intervals.
No. There is no core return required.
Augustus W. –
Got an RTLO-18918 for a 2015 Peterbilt 389 with Cummins ISX15 replacement. Model designation correctly identified as RTLO-18918 (1,800 lb-ft, NOT the higher-rated RTLO-22918 2,250 lb-ft), all 18 forward gears tested through both splitter and range positions, air system verified, clutch brake function confirmed. Honest pre-purchase information about the float-shifting technique and the Eaton family choice between 18-speed Roadranger (highway, this listing) vs 8LL (vocational per vaz131).
Lillian Q. –
Sourced an RTLO-22918 for a 2017 Kenworth W990 heavy-haul application with Cat C15 (per vaz85 listing reference). Model designation correctly identified as the higher-torque RTLO-22918 (2,250 lb-ft), donor truck documented, splitter and range selector air valves verified. Honest pre-purchase information about the twin-countershaft architecture and the proper Eaton-approved synthetic transmission lubricant requirement.