48 Cub - new fluids, oil pressure guage

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48 Cub - new fluids, oil pressure guage

Postby phill_mi » Sat Oct 09, 2021 2:49 pm

I got a 48 Cub this week, from a neighbor (who picked it up at an auction). As I am changing fluids, I noticed that the oil pressure gauge is full of oil behind the glass. Seems like this should be replaced. The gauge is under the gas tank on the side of the oil filter. Is it common to leave it there or move it to the dash where there is an unused location for a gauge. While I would like to maintain originality it is more important to me to have good functionality as I intend to work this Cub.

I also noticed that the filter drain tube was caked full of several inches of dry crusty gum. When I broke through it then a bit of oil drained out. Is this common? Any thoughts on whether I should take additional steps to clean out the engine, other than simply an oil change using specs form the latest manual. I am inclined to simply do the oil change, and possibly increase the frequency of oil changes, initially.

As I drove it home (~ 1/2 mile), I noticed a low frequency, but loud noise, that came and went, from the front area. In reading the manual and checking the 'brought an new cub home' check list, I am guessing the noise is due to lack of lub in the fan hub. It did seem to be dry so I put some gear oil in it. What is the purpose of that oil reservoir? Does the fan change rotation based on temperature or something.

Thanks for the advise. Phill

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Re: 48 Cub - new fluids, oil pressure guage

Postby Barnyard » Sat Oct 09, 2021 3:02 pm

The reservoir is to hold the oil that lubricates the fan bearing. Do not use gear lube in it as that is way to thick and will not help. You should use motor oil in it.
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Re: 48 Cub - new fluids, oil pressure guage

Postby Clemsonfor » Sat Oct 09, 2021 3:50 pm

Mine had the drain tube caked up with sludge as well. I poked through it with a screw driver and let it drain. There was lots of gunk in the filter housing as well. I tried to flush it out some with diesel. I filled it with fresh 15w40 and new filter. I eventually pulled the oil pan just a few hours later of run time worried about sludge in the pan, but also pan leaks. There was some junk in the pan but nothing to be worried about. The filter I took out was plugged up and was effecting oil pressure.

That is the factor position of the oil pressure gauge. It shouldn't have oil in the glass you should clearly be able to see the dial and the color behind it .

Barnyard is correct. The oil in the hub oils the bearing. It takes the same oil as what you put in the engine as does the air filter oil cup. You can download manuals for it here after 2 posts if you don't have one it details the oiling procedure of the hub if you didn't find that already.

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Re: 48 Cub - new fluids, oil pressure guage

Postby dgrapes59 » Sat Oct 09, 2021 3:56 pm

Welcome to the Forum!

Yes, the oil pressure gauge needs to be replaced, that's not normal. It sounds like it's in the correct place. Some people do move them to a more convenient place to view, but if you're wanting to keep it "original", leave it in that location.

That's pretty normal for the tube to be filled with solid crud, all 3 of mine were. Likely the prior owners never opened it up and drained it, probably just dropped the oil pan plug. It collects the sludge stopped by the filter and accumulates in the tube. How bad did the oil look when you drained it? I would just change it sooner, it's only 3 quarts :wink:

As Bill mentioned, a lighter oil is needed in the fan hub. The manual gives the procedure. Good you are addressing it, that's something that is often overlooked!

It sounds like you are off to a good start, best of luck with your new Cub!

EDIT.. I type slow.. :D

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Re: 48 Cub - new fluids, oil pressure guage

Postby Gary Dotson » Sat Oct 09, 2021 5:34 pm

1st. And most important, check here on the forum, for instructions and PRIME THE OIL PUMP.

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Re: 48 Cub - new fluids, oil pressure guage

Postby phill_mi » Sat Oct 09, 2021 6:07 pm

How bad did the oil look when you drained it?

It appeared black but not gritty to my feel. The neighbor that I bought it from said that he found the tractor about a week earlier at an estate auction and that he had changed the oil, filter, points, condenser and lubed the magneto, etc. He was not aware of the need to lube the fan hub. He said that he put 30 weight oil in the engine and ran it for a while around his yard. Too my eyes the oil looked dirty so I decided to change it. The filter also looks dirty to me, but the local parts store won't have a filter in until Monday. So I put new oil in it just to clean it out and I put motor oil in the fan hub, several times. I also pulled the starter and cleaned and lubed the bendix with dry lubricant, but that did not help the bendix problem. After I put it back together I ran the engine only for a short burst and then it did not want to start again. (I added to the problem by forgetting to open the gas shutoff valve.) I plan to do a full oil change when I get the new filter.

But when putting the motor oil in the fan hub it seems to run out the shaft where the hub mounts (which I did not notice when the heavier gear oil was incorrectly used). And when I crank the engine it squeaks and when it catches and runs that loud hum noise is very obvious, I think as bad or worse than when I drove it home. I get the feeling that I should look for a new fan hub or bearing/seal assembly.

I guess I am going to have to pull the starter and take it to my local starter shop or look for on-line parts. I also noticed that they have the #2 ground wire, so I need to get a proper ground wire for a 6 volt system.

On another subject I plan to change the fluids in the rear, but this has the Cub 22 sickle mounted on it. It looks like the Cub 22 pulley system needs to be removed to get to the drain plug for the left rear drive box. I don't think the bolts that mount the Cub 22 have been moved for a very long time, so that may become another challenge.
Thanks, phill

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Re: 48 Cub - new fluids, oil pressure guage

Postby Glen » Sat Oct 09, 2021 6:25 pm

The Cub fan runs at the speed the engine turns it, it doesn't change speed because of the temperature.

The Cub fan assembly has a built in oiling system in it. It uses motor oil to lube the bearing in it.
It should have thin motor oil in it.
The owner's manual below shows how to put oil in the fan hub, and drain the excess oil, so it has the right oil level, on page 28.
I would change it's oil as much as you can, if you put gear oil in it.
It has no hole for changing the oil, so you can only do a partial change at a time.
I use a clean pump oil can to put oil in the fan hub.

Drain the excess oil out, if you didn't before, and then put in motor oil, when the oil filler hole is in the right horizontal position.
Put in the screw, and turn the engine over about 20 times to mix the oils together some.
Drain the excess oil out.

Repeat that again, and drain the excess oil out.
Then it should have mostly motor oil in it.

It looks like you may have done that already, you posted above when I was writing this info.

The filler screw has a rubber seal on it, be careful to not lose it.
Sometimes it comes off with the screw, and sometimes it is stuck on the fan hub.

There is no oil seal at the rear of the original fan hubs, so some oil might run out there when you fill the hub.
The hubs seem to keep oil in them when filled to the right level.

You could check the fan bearing and see if it is worn, by holding the fan blades, with the engine off, and see if the fan moves any side to side.
If it needs the fan hub replaced, nowadays you can buy a new assembly with sealed bearings.
The Case IH dealer I buy things at was selling another brand a few years ago for not a big price.
Or J P Tractor Salvage at the bottom of the page might have a used one.

I think the oil pressure gauge is easy to see in the original position, you just have to lean to the right a little to see it.
Below is a listing at TM Tractor for new oil gauges. It says on the page before that they had them made to look like the originals.
I'm not sure if a 1948 Cub has the IHC on the gauge, or IH. You might be able to see it on your gauge, if it is the original.



I think the gauges with no numbers were 40 lb gauges, but not sure, that is a guess.
The Cub and LoBoy service manual says the Cub engine has a 35 lb oil pressure system.
IH started using a 40 lb oil gauge with numbers on Cubs in the mid 1950's.

The Cub owner's manual can help you learn about maintenance that the Cub needs.

Below is the 1949 Cub owner's manual. The experts on here recommend people read it. It has lots of info about operation, maintenance, and lubrication. There is a table of contents on page 1.
It shows how Cubs originally looked in it. The lube section begins on page 14.

http://farmallcub.com/rudi_cub/www.clea ... index.html

It shows the electrical system that a 1949 Cub originally had.
Cubs made before mid 1964 originally had 6 volt, positive ground electrical systems.

The 10 weight motor oil mentioned in the manual for the Touch Control was changed later to Case IH Hy-Tran fluid. It is sold at Case IH dealers.
There are other brands, be sure it works with IH hydraulic systems before buying one.
The manual tells how to check and change the Touch Control fluid, and remove the air from the system.
Be sure to check the fluid with the arms in the rear, or down position, the manual says.

I would check or change all the oils before using the Cub. Using it with low oil in a gear housing can damage the parts in the housing.
There are 3 separate gear housings, with 3 separate oil levels to check, in the rear area of a Cub, the transmission, and 2 final drives.

The transmissions in Cubs commonly get water in them, from rain, or condensation inside the housing over time.

The air cleaner is an oil bath air cleaner. Dirt that is sucked in settles to the bottom of the oil cup. It should have clean, light motor oil in the oil cup to work right.

There are more manuals at the top of the page at Cub Info, then go to Rudi's Manuals.

There is a search box at the top of the page, to the right of the Farmall Cub, you can find info in posts that have been made. :)
Last edited by Glen on Tue Oct 12, 2021 11:18 pm, edited 2 times in total.

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Re: 48 Cub - new fluids, oil pressure guage

Postby Waif » Sat Oct 09, 2021 8:43 pm

Early tractors ran nondetergent oil.
Sludge stacked up in low places. The drain tube was/is a good place for sludge.
IF your tractor was run on non detergent , then switched to detergent some of that accumulated sludge will be in suspension , thus mobile.
Keep an eye on the oil . You might be changing it frequently if sludgy. As with filter.

Review maintenance , preventive maintenance before you get running the Cub much. Could save you grief later.

Congrats on your Cub!

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