Description
Automann 139.2833 is a stroke-sensing Meritor Type B automatic slack adjuster with a 5-1/2″ arm and 1-1/2″ 28-spline input — a direct replacement for Meritor R802447 / R803049. The yellow-piston design holds shoe-to-drum clearance automatically across service intervals, and the unit ships complete with the 179.YK5005 clevis kit (5/8″-18 thread). Use on Class 6–8 tractors, vocational trucks, and air-braked trailers with Meritor drum-brake foundations.
Signs You Need a New Slack Adjuster
- Brake pushrod stroke exceeding chamber adjustment limits
- Visible cracks, corrosion, or impact damage to the body
- Loose arm or worn S-cam splines
- Adjuster fails to hold clearance after manual reset
- Seized or stripped manual-adjustment hex
- DOT out-of-adjustment citation on the air-brake foundation
Specifications
| Manufacturer | Automann |
|---|---|
| Part Number | 139.2833 |
| Part Type | Automatic slack adjuster |
| Adjuster Style | Meritor Type B (Type 2), stroke sensing |
| Spline Diameter | 1-1/2 in |
| Spline Count | 28 |
| Arm Length | 5-1/2 in |
| Clevis Thread | 5/8″-18 |
| Clevis Type | Straight (179.YK5005 kit included) |
| Piston | Yellow |
| Brake Type | Drum brake (S-cam) |
| VMRS Code | 013-017-005 |
| Warranty | 1 year |
Cross References
This slack adjuster replaces or is equivalent to the following part numbers:
- Meritor: R802447, R803049, R802445, R802649, R803047, R803053, A413275A1145, A353275A1145, A473275A1145, A583275A1145
- Euclid: E-11418, E-11418A
- Mack: 8235-R803049, TDAR803049
- Dayton Parts: 05-3631
Applications
Fits Class 6–8 tractors, vocational trucks, and air-braked trailers with Meritor drum-brake foundations using a 1-1/2″ 28-spline S-cam:
- Freightliner Cascadia, Columbia, Century, Coronado, M2
- Kenworth T680, T880, T800, W900
- Peterbilt 579, 389, 567, 365
- International LT, LoneStar, ProStar, 4400
- Mack Anthem, Pinnacle, Granite, CHU, CXU
- Volvo VNL, VNR, VHD
- Western Star 4900, 5700
- Air-braked trailers with Meritor drum-brake axles
Replace slack adjusters in axle pairs. Confirm spline diameter, spline count, arm length, and clevis thread before ordering. Measure the existing slack to verify match.
