Replaces the blank G56 PTO plate with a ported cover that raises the fill to 8 quarts on 2005-2010 Dodge Ram Cummins six-speeds.
If your Cummins Ram with the G56 six-speed tows heavy, runs hot in the tunnel, or you have already rebuilt one with dry, discolored rear bearings, the stock oil level and splash lubrication are the first things to improve. This billet aluminum cover replaces the blank plate over the G56 PTO opening. It has an IN port and an OUT port sized for -8 AN fittings so you can plumb an external pump and cooler, a 1/8 NPT port for a plug or a temperature sender, and a fill plug set higher on the cover than the factory fill hole, so the case can hold more oil. The listing rates it at 8 quarts when filled to the bottom of the cover plug. It weighs about 2.1 lb and comes with M10 x 1.5 x 25 socket head cap screws.
The G56 is a Mercedes-Benz designed six-speed with a two-piece aluminum case and no filter. It has a standard SAE six-bolt PTO opening, and trucks without a PTO simply have a flat plate bolted over it. Inside, the gears and bearings live on splash oil. Chrysler specified Mopar ATF+4 and roughly 6.1 quarts on 2005-2009 trucks and about 5.2 quarts on 2010-up trucks, filled to the plug on the passenger side just behind the PTO opening. Rebuilders have long argued that this is not enough oil for a box that tows. In the Turbo Diesel Register's G56 rebuild article, Standard Transmission reports that these units often came with too little lubricant, that the case is trapped in the floor tunnel with little airflow, and that units run on the factory fill come in with browned bearings. A ported cover attacks both problems: a higher static level keeps more of the rear bearings in oil, and the two -8 ports give you a circulation loop through a cooler instead of relying on splash alone.
This cover does not repair damage that has already happened. If the box already whines in every gear, rebuild it first with the G56 bearing and seal rebuild kit and then install the cover to protect the new bearings.
Look at the PTO opening on your G56 case. If it carries a flat blank plate on six bolts, this cover is a direct replacement. Pull the fill plug with the truck level: oil should be right at the bottom of the hole. If it is low, find the leak before adding capacity. Drain the oil and check the magnet; heavy glitter or bronze flakes mean the gearbox needs attention first. Our manual transmission repair cost guide helps you weigh a rebuild against a replacement unit if the damage is already done.
The listing covers Dodge Ram 1500 through 5500 trucks from 2005 to 2010 with the G56 six-speed manual, which in practice means the 2500 and 3500 pickups and the chassis cabs behind the 5.9L and 6.7L Cummins. Later Ram G56 trucks are not on the listed application, and the 2014-up cases gained split-shaft PTO provisions, so compare your cover and bolt pattern before ordering for a newer truck. The cover does not fit the NV5600 used in earlier Cummins Rams; those trucks need parts like the NV5600 short throw shifter kit instead. If you are not sure which gearbox you have, send us the year and VIN, or browse our transmission parts by model.
A shorter shift throw pairs well with this upgrade; the G56 short throw shifter bolts onto the same trucks.
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| Fill capacity to cover plug | |
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| Gasket | |
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| Fits |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
No. It includes the M10 x 1.5 x 25 socket head cap screws, but you need a G56 PTO cover gasket. Order one with the cover.
The listing rates it at about 8 quarts when filled to the bottom of the cover fill plug. The factory spec filled at the side plug is about 6.1 quarts on 2005-2009 trucks and about 5.2 quarts on 2010-up trucks.
No. You can plug the two -8 AN ports and use the cover only to raise the oil level. Adding a pump and cooler to those ports gives you circulation and extra cooling for heavy towing.
Chrysler specified Mopar ATF+4 for the G56. Some rebuilders prefer a heavier manual transmission fluid for towing because it holds up better hot. Pick one product and do not mix them.
It is not made for the NV5600. It is listed for 2005-2010 G56 trucks; on a later G56, compare the PTO opening and bolt pattern on your case before ordering, or send us your VIN.
