Oil Bath / Air Filter Missing Cup

[Parker_CJ3B]

1954 CJ-3B

Finally got to drive the 3B this weekend with the weather being nice in Georgia. Went on a 30 mile round trip and she ran pretty well, but idling a little rough. I changed the spark plugs prior to the trip and that seemed to help with startup and generally running. Looking at the carb next and the air filter. I've realized that my oil bath is missing the "cup" at the bottom, so no oil in the bath and the filter looks dirty. It must have fallen off during the last 72 years and no telling where it's at.

Replacement cups seem to be hard to come by for the 3B, not finding any sources on the internet and Kaiser Willys saying that about the only way to source them is through a junk yard or secondhand. If anyone happpens to have one, I would be interested in purchasing.

The other option is to remove the oil bath and go to a paper element filter. Kaiser Willys sells the parts that I think would fit. Adding a paper element filter to the top of the carb and an additional filter in place of the hose off the dipstick:

https://www.kaiserwillys.com/products/dry-element-air-filter-fits-50-71-willys-jeep-with-4-134-f-engine/

https://www.kaiserwillys.com/products/oil-dipstick-tube-clamp-on-filter-fits-41-53-jeep-willys/

Does anyone have any experience with these? Is this a better option than the OEM oil bath or do I need to search harder for a replacement cup? Will the cups for any other years work? It does not seem like it. Any other options to keep the oil bath housing? I'm not terribly concerned with keeping it stock looking under the hood, but it would be nice if I could.

Thanks in advance for the help.

[Rus Curtis]

Well that is unfortunate.  I can imagine it is possible to not have the strap tight allowing the cup to fall off.  Somewhere on the side of the road, in the tall weeds sits a cup - which will eventually be found.  Right after you replace or alter yours to work, it'll be offered on ebay for $5.00.

The issue with those cups is not keeping to the regular maintenance schedule and allowing water to accumulate.  Oil will float and the water accelerates rust down at the bottom.  So, many owners have discovered their cups leak.  This can lead to the imbalance that there are fewer serviceable cups than the main filter housing.

If you were to source a used unit, most times the seller is selling the whole filter.  And that may be better - knowing that they fit together.  I've seen cups for tractors on ebay but they're different.  You can see on the 3B Page, there's a baffle in the cup to help channel the air through the oil before travelling up through the mesh.

There's several ways to convert to an element filter with some of those on the 3B Page.

https://cj3b.info/Tech/AirFilterFix.html

https://cj3b.info/Tech/AirCleaner.html
(look under paragraph, "Replacements"

Right now, what I'm seeing on ebay are filter units that are very expensive.  I would try a salvage yard to see what you find.  FWIW, I travelled from Lawrence, KS to OK City, OK to pick up a Harrison heater and some other original parts.

[Parker_CJ3B]

Thanks for the reply. Both of those links are very helpful. Seems like going away from the oil bath is the move. The replacement cups are few and far between (I haven't seen one at all) and the cleaning process of the oil bath filter seems to be tricky. Not knowing how long that cup has been missing and the Jeep having lived on a farm most of it's life, I can assume it is full of dust and rusted out. I will keep the oil bath housing and parts just in case I ever want to go back or happen to come across the cup, but I've read you won't want to once you go away from it.

I believe I will go with either the Kaiser Willys K&N adapter option or explore more into keeping the oil bath housing and fabricating that filter that they suggested or finding something that fits in the housing is what someone suggested on another forum.

[SteveKfl]

Pricey, but may be what you are looking for on Ebay.  Good Luck!  PS... maybe contact seller for diameter dimensions to verify fit before buying since models are not given. 
 
https://www.ebay.com/itm/146944653062?_skw=Oil+bath++air-breather+pan+Willys+CJ3B&itmmeta=01KKVE4VCF8B1R1VYK46CQ73B5&hash=item2236957706:g:G2gAAeSwd39pDIYT&itmprp=enc%3AAQALAAAA4GfYFPkwiKCW4ZNSs2u11xBoN7W6s0czTLD%2F5x6ef2tct0m%2B8afn6yzybfZg1u3IjyLhD6SK4osluh8U1lNDcaXYftBMD8%2FDkL6NfCPjoaz45oJPkoalK%2FY3qno0fENCxbIT5RMmREXimF60ZNmRM5999f1cOmiy7QvXJX7Qn02KoByVdYS7%2B3XjksCPRUwcD1W2JzIpEYU9mK9XPHDlx7dNtjqRi93o39ZxOds0HuP%2FfaILxudYHS6Q%2BOvRSz7QyMtvwKaXNxCcA8DYc8jUbGb9WaVELlNiSaMhZmroUjzK%7Ctkp%3ABk9SR7K2k-6eZw

[Parker_CJ3B]

I saw this one and asked for dimensions, would be worth the price if it works. If I go the K&N route, there is still a pipe that comes out of the oil dipstick into another pipe that comes out of the head of the engine and into the oil bath. Any idea what I would need to do with that pipe? Could I attach the K&N oil dipstick filter on the end?

[SteveKfl]

For me, I'm not familiar with the K&N filter you're considering.  I think the screen does most of the work in the original filter, and pic shows it has worked in the past collecting dirt and dust.  The oil only captures the heavier than air materials/critters falling into it, not the micro particles that get caught by the screen.  Oil prevents the rust potential mentioned as well.
 
What I did to improve the "micro-particle filtering" on mine, I added a filter material (lawnmower air-filtering material) onto the intake vents of the breather to stop the critters and rocks.  Easy to remove and clean.  You just need to cap off the bottom of yours to keep the "air flow sucked in from the top backside" as intended.  May not have the oil benefit, but looks more original than a K&N and has the tube-connection service that you're asking about too.  Anything to cap off the bottom, like maybe a bowl or cake/pie pan, with the correct diameter, to be held in place with the clamp system, (that I see you still have), will work. 
 
When attaching the oil breather tubing to the K&N filter, note too much suction can affect the oil in the crankcase as well as may not get "filtered", depending on location chosen.  Don't CJ3Bs have a PCV system?    Just offering options to "keep the look" as much as possible.  Have fun with it.   

[Rus Curtis]

I saw this one and asked for dimensions, would be worth the price if it works. If I go the K&N route, there is still a pipe that comes out of the oil dipstick into another pipe that comes out of the head of the engine and into the oil bath. Any idea what I would need to do with that pipe? Could I attach the K&N oil dipstick filter on the end?

My two cents is I'd steer clear of this ebay offer.  The Parts Manual states, "No Part Number," for our cup.  That's another tick on the suspicion list.  You're still waiting on the dimensions.  It comes from Netherlands.  The issue most important to me is the insides.  I don't see the necessary baffle - and I'm unfamiliar with that recessed center.  My guess is it fits a different style breather.

I have never seen one of these oil bath breathers operate from the inside, but if I'm interpreting the diagrams and descriptions, I believe all air is forced through the oil because of this baffle.  Then it bubbles/percolates/splashes up into the mesh.  I believe this is what works so well with these filters; the oil and mesh combination.  I don't believe any air bypasses the oil (assuming the oil level is where it's supposed to be).  I've read that paper is better at small particles, but some oil bath resources state an oil bath is more efficient. 

I "re-found" one article on function.  There's a link on the 3B Page section on Air Cleaner leading you to the article which is on the 3A Info Page:

https://cj3a.info/tech/aircleaner.html

As far as the hose on your filler tube, it is part of your crankcase ventilation.  Before PCV valves, pressure could build in the block and either a vent was added or it would find its own way out.  A draft tube was used early on.  To contain it all and keep it more waterproof, it was plumbed and recycled back to the carb.  The PCV valve kept the backflow pressure from happening.  The fittings on top would draw air in and circulate out through the PCV valve. back to the manifold.  See the diagram in the SM Fig 111, pg87. or here on the 3B Page:

https://cj3b.info/Tech/PCV.html

I've seen a small filter attached to the filler tube on some engines but you could also fabricate a connection to the filter inlet similar to the stock breather.  I've seen three different types of valve covers:  One has a 90 degree fitting to route a hose to a "T" fitting on the filler tube hose.  Another has a breather type cap with no option to connect a hose.  And the third has no opening at all.  If I were to guess, I'd say eventually, the idea that an additional vent wasn't needed.

[SteveKfl]

FYI... There is a large air gap between the shallow oil level and the bottom of the mesh.  The 180 degree turn of the air to go back "up towards the carb's suction" thru the mesh, is the SECOND "radical turn" (first one at the intake to the downward-sleeve area) that separates "heavier particles" to DROP and be "CAPTURED in the oil".  No air goes thru the oil.  There is a short ramped up area above the oil line, and then a deeper recessed cup area in the center.
 
From the link referenced...
"The shroud on the inside of the pre cleaner section directs the dust laden air by turning it 90 degrees, down into the oil cup, where it immediately turns 180 degrees to go up to the mesh screen. This causes the heavier dust particles to separate from the air stream and be captured by the oil."
 
I can take pics of mine if needed.
 
Also, I used to be involved with ebay selling, and sellers sometimes "create their own inventory part numbers" for items for "their inventory use", not necessarily a Willys part number indicated.
 
Maybe  a member has an extra?  Try a WTB at the bottom of this site???  Happy Hunting!

[Chuck W.]

I'd check with Harry Sheets at Midwest Willys

[Parker_CJ3B]

I reached out to Midwest. They said they couldn't just sell that part, which makes sense. I asked how much for the whole unit, scared to know the answer.

My engine has the hose coming off the block and into the oil bath. The hose off the dipstick T's into the hose from the block. If I went the route of using the K&N options for the time being until I can source a replacement cup or oil bath, I think I would attach the K&N filter to the boot on top of the carb and then the K&N filter for the oil stick on the other side of the T. In my mind that is doing the same thing as both lines going to the oil bath, but correct me if I am wrong. Parts I have on the way from Kaiser Willys are:

Carb Filter: https://www.kaiserwillys.com/products/dry-element-air-filter-fits-50-71-willys-jeep-with-4-134-f-engine/
Dipstick Filter: https://www.kaiserwillys.com/products/oil-dipstick-tube-clamp-on-filter-fits-41-53-jeep-willys/

If I can source a cup, I may end up comverting it to a paper filter similar to the article Rus sent: https://cj3b.info/Tech/AirFilterFix.html to not have to deal with the bath and not knowing if the cup I find will work as intended. Alternatively if I can't find a cup, I could use a stove pipe cap or similar metal to clamp onto the bottom to force air in correctly from the back.

I'm hesitant to drive the jeep any more as is, not knowing how much junk is in that oil bath already and what could come in. I would feel safer with the temporary K&N option.

I've attached some additional photos.

[Parker_CJ3B]

FYI... There is a large air gap between the shallow oil level and the bottom of the mesh.  The 180 degree turn of the air to go back "up towards the carb's suction" thru the mesh, is the SECOND "radical turn" (first one at the intake to the downward-sleeve area) that separates "heavier particles" to DROP and be "CAPTURED in the oil".  No air goes thru the oil.  There is a short ramped up area above the oil line, and then a deeper recessed cup area in the center.
 
From the link referenced...
"The shroud on the inside of the pre cleaner section directs the dust laden air by turning it 90 degrees, down into the oil cup, where it immediately turns 180 degrees to go up to the mesh screen. This causes the heavier dust particles to separate from the air stream and be captured by the oil."
 
I can take pics of mine if needed.
 
Also, I used to be involved with ebay selling, and sellers sometimes "create their own inventory part numbers" for items for "their inventory use", not necessarily a Willys part number indicated.
 
Maybe  a member has an extra?  Try a WTB at the bottom of this site???  Happy Hunting!

Do you mind sending pics of yours? Midwest Willys responded with pictures of the unit they have available. Price seems okay. But it looks different from what is installed on my 3B currently. Now I'm questioning which one is correct, if the one on mine was replaced at some point or if the cup from the Midwest one will fit on my existing oil bath or do I just swap oil baths entirely and it will still work. Pictures attached, but there is an additional baffle/ring on the outside compared to the one installed on my 54.

For what it's worth, the cup looks very similar to the eBay listing for the cup only. Obviously cheaper to go that route but the benefit of buying the whole unit is I will have a replacement filter. The eBay cup is 6.88 inches diameter (17.5 cm). I need to get home to compare that size to the base of my oil bath.

[Chuck W.]

My copy of the Universal  Parts List shows 910289 as the correct cup for the CJ3B air cleaner

Hope this helps, here's the one off my '64

[Rus Curtis]

That is a good breather from Midwest.  Just a bit later model as Chuck is showing.  If it's a good price grab it!

Then you can go either way for filtering.  It appears that your hose plumbing is correct.

[Parker_CJ3B]

It certainly looks cleaner than my current situation. Hopefully no issues swapping my current to it, it looks like it has the same connections, just slightly different look.

This is all new to me. I'm used to modern cars where I can walk into the parts store and find what I need. Guess that's part of the adventure.

[Chuck W.]

Parker, if you are not interested in that cup on e-bay, I may be interested in it, that is a good price for an NOS unit and it's always nice to have a spare as they are bad to get water in the bottom under the oil and rust out.

Edit: Never mind, I just noticed the shipping price, holy cow!