Muncie RS, RC and RM rear mount PTO parts
Rear mount PTOs bolt to the back of automated and automatic transmissions that have no side opening to use. Here is which model goes with which transmission and how to read the tag.
Send a photo of your PTO tag and we will confirm the model.
RS / RC / RM at a glance
- Type
- Rear mount PTOs: RS4S (4-bolt), RS6S-P89M (6-bolt), RC1 and RM1
- RS4S models
- P81, P82, P84 and P86, mechanically shifted
- Top rating
- 675 lb ft intermittent (RM1); 442 lb ft (P81Z2)
- Approximate weight
- 17 lb (P81), 23 lb (P84 and RS6S-P89M)
- Parts books
- SP04-02 RS4S, SP18-05 RS6S-P89M, SP15-01 RC, SP15-02 RM
What the rear mount series are
Muncie's rear mount line covers transmissions where the usable PTO opening is on the back of the case. The RS4S is the main family: an air shifted gear unit, sold as the P81, P82, P84 and P86. The RS6S-P89M is a 6-bolt unit for Detroit. The RC and RM are clutch shift units for Allison, with a 12 volt electric and hydraulic shift.
Where it fits
- Volvo I-Shift and Mack mDRIVE: the P86 series, listed as RS4S-P86VN-P1CX and RS4S-P86VM-P1CX. It has two gears that change rotation and speed, and a DIN 5462 pump pad as standard. Muncie asks that the chassis be programmed for PTO use and recommends pressure lubrication for continuous duty.
- Eaton Endurant HD and PACCAR TX-12: the P81 (1:1) and P84 (about 0.9:1). Muncie publishes a clearance chart by Eaton output yoke number, because some yokes block one or both units.
- ZF/Meritor FreedomLine: the P82Z1 and P86Z. Spicer SPL 175 and SPL 250 yokes interfere with all of them.
- Eaton Procision and Lightning: RS4S installation manuals exist for both, including the P82E3 for the Procision.
- Detroit DT12: the RS6S-P89M, for Freightliner and Western Star Cascadia and 5700 trucks that have the PTO prep kit.
- Allison TC10 TS: the RM1. The RC1 takes Allison or Caterpillar input.
| Model | Ratio | Torque rating |
|---|---|---|
| RS4S-P81Z2 | 1:1 | 442 lb ft |
| RS4S-P84Z2 | 1.29:1 | 300 lb ft |
| RS4S-P84Z4 | 0.92:1 | 369 lb ft |
| RS6S-P89M1, M2, M3 | 0.97, 1.32, 1.83 | 317, 317, 295 lb ft |
| RM1 | 1:1 | 675 lb ft |
Reading a rear mount model number
An RS4S tag reads: series, mounting type and ratio, shift, assembly arrangement, output, special feature. Muncie's example is RS4S-P84Z4-P-1-C-X: a P84 with the 0.92:1 ratio, air shift without activation controls, standard arrangement, a 1310 companion flange and no special features.
- Shift: P is air shift less activation controls, E is electric over air.
- Output: C is a 1310 companion flange, I is DIN 5462, K is SAE B and P is SAE BB.
The RS6S-P89M uses the same pattern, for example RS6S-P89-M1-P-1-P-X, where M1 to M3 are the ratios. RM and RC tags such as RM1-UC1 10-HX 1 X4 PX and RC1 UC2 10 HX 1 CC PX show mount, 1:1 ratio, shift, arrangement, output and pressure lube.
Parts that wear and what to order
- Mounting kits and stud kits for the RS4S, by output option, with the transmission shaft kit 601K5400000 for the P82Z1 and P86Z.
- Activation and wiring kits, including 48TK4637, 48TK4636 and 48TK4635 on the RS4S.
- Output and pump flange kits: the SAE B kit, the direct mount pump flange kit and, on the RM, companion flange kit 14TK5664.
- RC gasket kit RC1-GSK and rebuild kit RC1-RBK, which carries the clutch discs and bearings.
- RS6S transmission output shaft assemblies 601K6930000 and 601K6950000, sold as kits.
- RM installation kit 48TK5469 and the SAE B and SAE C cover kits.
Questions we get about rear mount PTOs
How heavy a pump can I hang on it?
On the Eaton Endurant opening, the total mass of PTO and pump is limited to 90 lb, with a support bracket for direct mount pumps. Limits are lower on the P82 and P86 DIN pad, 30 lb, and 25 lb for SAE B. The RS6S-P89M carries pumps to 60 lb on its own mount.
Does the transmission need programming?
Yes, in each case. The Eaton Endurant control unit needs the right vocational logic, and the Volvo, Mack and ZF/Meritor installations call for PTO programming from the chassis maker.
Which of these is the clutch shift model?
The RC and RM. They use a clutch pack or face clutch and a 12 volt electric and hydraulic shift. The RS4S units are air shifted gear PTOs.
RS / RC / RM parts breakdown
How the Muncie RS, RC and RM Rear Mount PTO parts list is organised on our store. Each section opens the exploded view with every part number, the quantity used and an order button.
Muncie RS4S Series
Muncie RS6S-P89M Series
Muncie RC Series
Muncie RM Series
RS / RC / RM manuals
All RS / RC / RM books: Muncie PTO parts manuals.
Need a complete rebuilt unit?
Our sister site rebuiltmunciepto.com covers rebuilt RS / RC / RM units. This site is the parts and model reference side.
Get a quote on RS / RC / RM parts
Send the model number off the PTO tag, a part or item number, or simply what the PTO is bolted to. A parts specialist answers during business hours.