New Onan 5500 gen - oil change and air filter questions

[whs9841]

I have a new Fuzion 331 with an Onan 5500 gas generator (I believe it is model HGJAB). I just used the trailer to dry camp last weekend and ran the generator all weekend. I need to change the oil, oil filter, and air filter, but I'm finding conflicting information online.

Regarding the oil, I live in Tx and don't experience extreme cold temperatures. I'm assuming I'm fine using 10W-30 oil. Is it okay to use a full synthetic or synthetic blend?

Regarding the oil filter, I'm finding some documentation says I should get the 122-0833 filter, and other documentation says I should get the 122-0836 filter. Does anyone know which one I should use?

Regarding the air filter, is part number 140-4151 the correct air filter?

Thanks in advance.

[Ductape]

Good choice.
For mine I went to 5W40 synthetic Rotella at the second oil change. I have spent a lot of off grid time with portable generators over the years and in my experience synthetic for air cooled engines pays dividends in reliability and fuel use.

YMMV.

[whs9841]

I went to the storage facility on Saturday to get the exact model and S/N from the generator, and voila, the oil filter and air filter part numbers were listed on the front of the generator.

I'm planning on using 15W40 oil for now. The manual shows a temp range of 10 to 100 deg F for 15W40, and I don't see us using the generator outside of that temp range. I guess there's a chance we might need it when the temperature is a little over 100, but I think we'll be good.

[Clay_L]

Note that the last of the two quarts of oil takes a long time to pour in.

In order to speed it up some, I fill the filter before I screw it on.

I also screw the dip stick back in and turn the engine over for a 10 seconds or so. This seems to pump some oil into the engine and speeds up the fill process for a while. I usually have to do that two or three times.

I used 30 weight oil in it for years but when I switched to Mobile One synthetic 10W30 oil in my 8.1L engine I started using it in the Onan also.

[Camper_Ken]

I use Shell Rotella 15w-40. Some think it's only for diesel engines, but not true. It's a good heavy duty oil. I checked with Onan and they said yes, it's definitely recommended as much as their own Onan branded oil. Use the "836" filter.

[64thunderbolt]

replace with the same filter that was on it. I dry camp 99% of the time so every spring I change the oil no matter how many hrs. Cheap ins.

[whs9841]

Thanks Wyo. Calling Onan is probably the best bet.

[WyoTraveler]

On my Onan 5500 gas generator I use 122-0836 oil filter and 140-3116 air filter. Your manual should contain all of that info and info on oil and temp. If in doubt Call Onan and give them your model and serial number they will give you the info you need.

Onan parts phone: 1-877-938-6762

They were real helpful to me.

BTW: I tried a Napa generic oil filter first. They are shorter and would not fit properly. Onan said there is a check valve in the Onan filter that prevents over pressure.

[whs9841]

Vet, are the two oil filter options the ones I mentioned? It may be the 0836 is just a little longer. I did read something about the 0833 not having a wrench and that it's hard to get to.

[Vet_Man]

I use 10-30 all the time, and do not use synthetic oil but many people do. On mine there are 2 filter options, one is just longer so it sticks down further for ease of removal. My filter is removed from underneath, and allows you to get a filter wrench on easier.