Detroit Diesel 92 Series Engine and Allison Transmission Oil Change

Encore has two Detroit Diesel 6v92 engines paired to Allison Transmissions. As per the 92 Series user manual, the engine oil is to be changed every 150 hours. I have been changing the transmission oil during every other oil change (300 hours).

I never exceed those hour limits, but I will change the oil sooner based on in service time. For the engine oil, I change it every 150 hours or every 12 months, whichever comes first. For the transmission oil I change it every 300 hours or every 24 months, whichever comes first.

Transmission Oil Removal

To remove the engine and transmission oil it is favorable to run the engines to allow the oil to warm up. This will the make removal process much quicker as the oil will pump out much faster when hot.

To remove the old transmission oil, I use a small 110v pump. The supply side of the pump is connected through a hose to the dip stick tube on the transmission. The hose goes over the dip stick tube and is sealed to it with a clamp. The discharge side of the pump also has a hose connected to it that runs to an oily waste container.

Transmission Oil Filter Replacement

The oil filter for the transmission is an element type filter. I’m using a Donaldson P550147. There is a bolt that screws in through the bottom of the filter housing for removal and install.

The filter/housing will be filled with oil when removing it. I’ve used a plastic bowl during past oil changes to catch what comes out. This time I used a garbage bag. I found both methods to be only partially effective. On this boat for sure, this job will be messy. I had plenty of oil absorbent pads at the ready and placed under the filters.

I did not fill the filter with oil prior to reinstalling it. Due to its location, it is impossible to get the filter reinstalled without spilling the contents.

The Donaldson filters come with a new gasket kit. All gaskets were replaced. An ice pick is a good tool to use to remove the old gasket.

Filling the Transmission with Oil

I filled the transmissions by hand using Shell Rotella T1 SAE 40. Each holds approximately two gallons of oil. The level is checked with the engine running.

6V-92 Oil Change

The process for changing the engine oil is very simple. Located on the bottom of the oil pan for each engine is a ball valve. I have a hose connected to that valve that runs to the aft side of the engine.

I use the same 110v pump with the supply side connected to the hose leading from the oil pan. The discharge side of the pump has a small section of hose connected to it and runs into an oily waste container. The hoses are flopped once it’e time to refill.

Each engine holds slightly over five gallons of oil. The level is checked on the dip stick throughout the filling process and as often as needed once the level is approaching the full mark.

6V-92 Oil Filter Replacement

The location of the oil filters on Encore make their replacement a little messy. Each is located on the aft side of the engine just starboard of the transmission. Below the filters for both engines is a small transverse stringer. There is very little clearance between the bottom of the filter and the top of the stringer.

Luckily, there is enough space between the stringer and filter on the port engine to slide a filter wrench in and remove the filter. On the starboard engine, the clearance is almost nothing. The mounting bracket for the filter needs to have two of its three screws removed. The filter can then be rotated to create the necessary clearance.

Replacing the filters can be very messy. As soon as the filter is loosened, oil will flow from it. I have used a small bowl in the past to catch the oil coming out. It worked ok, but the problem is getting the bowl out without spilling its contents. For this oil change I used a garbage bag spread out under the filter. This method worked a little better, but is still not great.

The new filters are Fleetguard LF3333. I have used Donaldson filters in the past, but went with Fleetguard this time only as a matter of convenience. The store where the Rotella oil was purchased from (great price) had Fleetguard filters in stock. It is a little strange seeing a Cummins product on a Detroit Diesel engine though.

Oil/Filter Change

Changing the oil and filters for both transmissions and both engines took about five hours. I did not fill the engine oil filters with oil prior to installing them. If I had most would have spilled out trying to get them installed. Due to that, I had to add oil after running the engine for a couple of minutes once the filter was filled.

I’ll definitely keep trying to improve the filter changing method. No matter what plenty of oil absorbent pads will always be available.

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