Eaton Fuller 13 speed shift pattern: what the 21756 label shows
The 21756 decal is printed for the RT-6613 only (the label backing reads "Models: RT (ONLY) 6613"). The RT-6613 is the older style 13-speed: a five-position H-pattern with two ranges plus a deep reduction (Lo-Lo) selector on the knob, rather than the range-and-splitter layout used on later 13-speeds. Reading the label from the driver's seat:
| Lever position | Low range | High range | Deep reduction (Lo-Lo) |
|---|---|---|---|
| Top left | R | R | R |
| Top center | 2 | 7 | LL2 |
| Top right | 4 | 9 | LL4 |
| Bottom left | 1 | 6 | LL1 |
| Bottom center | 3 | 8 | LL3 |
| Bottom right | 5 | 10 | LL5 |
The label's printed progressive sequences are LL1-LL2-LL3-1-2-3-4-5-6-7-8-9-10 (thirteen forward steps). Upshifting: start with the range selector down, shift 1-2-3-4-5, raise the range selector, then shift 6-7-8-9-10. Downshifting: 10-9-8-7-6, move the range selector down, then 5-4-3-2-1. Pre-select range shifts, never change range while moving in reverse, and start the engine in neutral.
How the range and splitter work on an RTLO / RTO 13 speed
Most 13-speed trucks on the road today run an RTLO or RTO model, and those use a different pattern: Lo, 1, 2, 3 and 4 in low range, then 5, 6, 7 and 8 in high range with each gear split by the splitter button (H and L positions), which is what makes thirteen forward speeds. The splitter may be shifted in 5-6-7-8 only, and you must not range-shift with the splitter in H. Upshift Lo-1-2-3-4, raise the range selector, then 5-6-7-8; downshift 8-7-6-5, range selector down, 4-3-2-1-Lo. That layout is printed on the Eaton Fuller 4300764 RTLO 13 speed shift pattern label, and the matching knob-top insert is the 5586113 13 speed shift knob medallion. The RTO-6613 has its own deep-reduction decal, Eaton Fuller 21817.
Which 13 speed shift pattern label fits your transmission
| Transmission model | Pattern type | Shift pattern label |
|---|---|---|
| RT-6613 | Range + deep reduction (Lo-Lo) | 21756 (this page) |
| RTO-6613 | Range + deep reduction (Lo-Lo) | 21817 |
| RTLO-16913A, RTLO-18913A, RTLO-20913A, RTLO-14613B, RTO-14613 and other RTLO / RTO / RTOF / RTOX / RTOXF 13-speeds | Range + splitter | 4300764 |
Your model number is on the data tag on the passenger side of the unit; if it is unreadable, call us with the TA or serial number. Browse every in-stock unit in our Eaton Fuller 13 speed transmissions category.
13 speed shift knobs and air line kits
The genuine S-2578 13 speed shift knob with medallion and the A-6913 13 speed shift knob master valve are the two knobs that fit the RTLO / RTO 13-speed family, and both are available as S2578-KIT and A-6913-KIT bundles with the ALK1 air line kit.
Part details
| Part number | 21756 (also written FUL 21756, 3088-21756, ZBF21756) |
|---|---|
| Brand | Eaton Fuller |
| Type | Shift pattern instruction label / decal, peel-and-stick |
| Application | Eaton Fuller RT-6613 13-speed transmission (RT only) |
| Pattern | 5-position H, low / high range, deep reduction Lo-Lo (LL1-LL5) |
| Size | Approximately 12 in. x 12 in. |
| Ships | Free shipping, usually ships in 3 to 5 business days |
Features
Shift pattern instruction label for Eaton Fuller 13-speed RT-6613 transmissions
Manufacturer part number 21756
Cross references: 3088-21756, FUL 21756, ZBF21756
Approximately 12 in. x 12 in.
Genuine Eaton Fuller part
Tech Specs
- Part Number: 21756
- Application: Eaton Fuller 13-Speed RT-6613 Transmission
- Type: Shift Pattern Instruction Label / Decal
- Dimensions: approximately 12 in. x 12 in.
- Cross Reference: 3088-21756, FUL 21756, ZBF21756
