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Posted

Does anyone have a seal number for the rear axle on a 1920 K-45.   I recently had my wheels rebuilt and would like to install new seals, either modern lip or original felt type.

Posted

I replaced mine with seals obtained from the seal shop by size. The seal number is the size. They are NAK brand I think. For felt seals, you can probably make your own and put them in the original holders.

Posted

In case you want to go with a lip seal on your rear wheels, I have a technical paper that I have been working on.  1920 is a little earlier than my paper, so edit as you go and I do not entirely know what is applicable to you, but this will be close.  I am also guessing on what to torque the rear axle nuts.  Much of this paper are thoughts and comments that I have picked up on this forum.  You probably missed many of these discussions since you are new.  The forum only lets me post as jpeg, so I found it easier to snip photos of the pages so that I can paste them here.  Also note that I have broken axle keyways on my car which I will attribute to a previous owner not securing the rear wheel bolts correctly.   So the job is more than just replacing seals, it is also about reinstalling parts correctly .   There is also a bit about the theory on how all this works, and understanding the theory will make you a better mechanic.

I hope this helps you.   Hugh      

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  • Like 2
  • 1 year later...
Posted

Hugh,

Thanks a lot.  You are so good at these things.  I will save this and try to modify it for 1921/22 style, great idea.

 

Mark

 

 

  • Like 1
  • 1 year later...
Posted

Hi Hugh -

 

Great information here.  I drove my 25 about 10 miles today at 35 - 40 mph and when I got back to my shop I saw oil slung all over the outside of my right rear tire and wheel so I figure I have an oil seal failure.  I did fill the differential with 600W oil to the fill hole before I took her out. You mention in your notes above that some people recommend filling one inch below the file hole.  Do you think I overfilled the differential that caused the leak or the felt seal has failed?

 

Thanks,

Ken

Posted

Ken

Probably not a seal issue.  Look at the underside of the rear axle where the backing plate flares and you will see a tube (1/2" x 3" long) pointing down wards at around 45degrees. This is the overfill drain tube. If you just filled the differential and then drove down a 2 lane road with a crown, the right wheels will be lower, and the oil will find its way out the drain tube.  The tube directs the oil away from the wheel, so if this tube is missing the oil will get all over the wheel.

Post a photo if you don't see the tube. 

Kevin 

  • Like 1
Posted

Ken,

 

Larry DiBarry and I talked about this very issue earlier this evening.  Cleaning up the rear axle assembly for my '16 D-45 is the last thing left to do before it goes back up under the car.  I'm taking it to my John Deere dealership  for high pressure washing with a strong grease cutting agent added.  I want to drain the rear axle oil and check out the gears before adding the new oil.  I asked his opinion about how much goes in.  He told me to stick my 'pointer finger' in the fill hole and that when I touch the oil that should be enough.  This makes good sense to me because I believe you might have an over-filled condition from what you have described.  I have great condition brake lining on the axle and the Good Lord knows what oil and/or grease does to brake lining material.

 

Terry Wiegand

South Hutchinson, Kansas

  • Like 1
Posted (edited)

Ken, 

   At this point I think you overfilled it.  Just keep an eye on the level after a couple of drives.  It should begin to maintain itself at 1" below the fill hole.  Keep the oil away from the brake bands as once oil gets on them it cannot be removed and the lining has to be replaced.   Glad that you were able to go on a drive.    Hugh

Edited by Hubert_25-25 (see edit history)
  • Like 2
Posted

All - 

 

I don’t see the drain tube that Kevin mentions in his post.  It looks like both sides are plugged. See photo. So can I just replace the plugs with a 1/2” x 3” pipe thread nipple?  

 

When I was driving the car I would occasionally pull over to the right shoulder to let traffic pass me on the left. This sounds like the condition that Kevin is describing with a crown in the road and also explains why I didn’t get any oil on the left tire.

 

I think I got lucky and didn’t get any oil on the brake shoes or drum at least I don’t see any oil there but I haven’t removed the shoes to double check. It’s not obvious where the oil came from. I took off the hub cap and didn’t see any oil inside the hub or on the hub cap. It almost looks like it came from where the hub mounts to the wood spokes. It slung oil all the way around the inside of the fender (outer edge) so I am pretty sure the oil leaked only to the outside of the backing plate.

 

The irony here is the oil level was 1-inch below the filler hole before I ‘serviced’ it... I’ll make sure the level is where it was before and drive it for a while to make sure it’s not leaking.

 

This was the first time I drove the car without a break down. And the longest drive yet.  It runs cool and quiet (for an open car). The engine with the roller rockers sure runs smooth. I really was impressed how comfortable the car is. I put modern shocks on one of my Model As and the Buick with the stock suspension is a far better ride. I need to get the new Venturi installed as the engine idles fine most of the time but about 25% of the time its rough. That's probably my next project.

 

Thanks everyone - great advice.

Ken

 

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Posted (edited)

With those drain holes plugged, the oil probably was seeping out of the seal which would lead to the brake lining getting oiled. 

The drain tube is supposed to direct the oil away from the wheel and brake lining. 

I think its 3/8 NPT. pitch is 18 and outside diameter was about .670

My axle is a '28, so it has a snubber loop which your car does not have. 

Kevin 

 

drain tube.jpg

Edited by Oregon Desert model 45 (see edit history)
  • Like 1
Posted

Interesting I took the brass plug out and it didn’t have any sign of oil on the end of the cap. I don't know how the oil got past the plug without getting oil on it but it did. No matter, I am pretty convinced the leak was because I overfilled the differential.  I checked the fluid level and it was almost full so very little of the volume leaked out but enough to make a major mess!  I think I caught it in time before the brake shoes got contaminated.

 

And yes you are correct the threads are 18 pitch and outside diameter about .670.  I am going to take the brass plug with me tomorrow to the hardware store to pick up some nipples. Sure glad I don’t have to replace the seal...

 

Thanks again

Ken

  • Like 1
Posted

I drained the oil level down about 1-inch and took her back out for a short drive and got the same result. Oil on the outside of the tire.  It is localized in the same area that I cleaned up the first time. Looking carefully in that area I saw a threaded hole in the hub that I assume is for a grease zerk.  It’s pretty obvious now that is where the oil came from.  I put a grease zerk fitting in but not sure how much wheel bearing grease to pump in there. How do you know when you have it full. Does it seep out inside the hub?

 

I hope the oil I saw this last time was residual oil in the hub before I lowered the oil level.  Would oil in the are indicate a failed seal or do you think it is residual oil in the hub?

 

Thanks,

Ken

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Posted (edited)

That hole should have a slotted brass plug.  Wheel bearings are also lubricated by the differential oil.

These old cars are just full of surprises aren't they ?  

Finding and fixing all these little bugs is what we call "sorting out", and you seem to be making good progress. 

Kevin 

Edited by Oregon Desert model 45
edit (see edit history)
Posted

Kevin -

 

I am sure glad I asked you about that hole before I pumped it full of wheel bearing grease... I’ll pull the zerks and replace them with brass plugs. Just curious do you have any idea what the holes are used for? Inspection to make sure there is differential oil in the hub or is it used to drain oil out or maybe to squirt oil in?

 

Which brings up a question about the differential supplying oil to lubricate the wheel bearing.  I lowered the oil level in the differential by about 1-inch.  Do you think this lower level will impact how the differential oil gets to the wheel bearings?

 

Yes I have been doing a lot of ‘sorting out’ this last year but finally making some good progress with all the help I have been getting. Just got around to ordering a ‘parts book’ from Bobs for my 25 model year.  That should help me a lot in my sorting out endeavors 😃

 

Ken

Posted

Ken

This is what 1925 Master Shop manual recommends. Standard should be the same.

REAR AXLE

Use steam cylinder oil for temperatures above freezing. For temperatures below freezing mix steam cylinder oil half and half with engine oil of a cold test not to exceed 5 degrees fahrenheit. 

Keep housing filled to level of filler plug opening.

Wash housing out thoroughly with kerosene at least once each season and refill with fresh lubricant

WHEEL BEARINGS

Use soft cup grease

Fill through plug hole in hub every 1000 miles. 

 

So maybe installing a zerk fitting in the hub temporarily to pump in grease is the correct procedure ?   

I suggest also poking a wire in the drain tube to make sure the passageway is clear, and then fill the differential oil back up to the opening.

I am still learning too, so hopefully other owners will confirm.

Kevin 

 

 

 

 

 

  • Like 1
Posted

I changed my bearing to permanently greased type and don’t have to worry about them getting lube any longer

  • Like 1
Posted

Kevin -

 

I think the consensus from the previous posts was that I overfilled the differential.  I followed the shop manual guidance and filled it to the level of the filler opening.  It was only when I filled the differential full did the 600W oil leak out of the threaded hole in the side of the hub. And it only leaked out of the right rear wheel probably due to the road crown as you mentioned earlier.  So I am thinking that if the differential is 1-inch or lower in fluid then there might not be sufficient oil being delivered to the wheel bearings.  It seems to me that if the manual says to fill oil to the opening and not 1-inch below then I agree I probably should refill to the filler opening. Any thoughts from others?

 

I removed the grease zirks and with a flashlight I can see inside the hub. There is no obstruction.  I made some drain tubes out of 3/8” pipe with the dimensions you provided and installed them.  I have a 25 Master rear axle in my bone yard and saw the filler tubes had a slot at the open end so I slotted the new ones.  The slots made it easy to tighten with the flat end of a screwdriver.

 

Thanks,

Ken

  • Like 1
Posted

I don't know if your modern vehicle is like my 17 D45?  I took photos of my junk differential housing.

Photo 2 shows screwdriver extending into the brake area.

 

photo3 shows the baffle in the axle tube that is to prevent heavy flow of fluid into the brake area.

 

Photo 1 shows screwdriver inserted in drain hole.

 

BobEngle

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17dif2 - Copy.jpg

17diff1 (2) - Copy.jpg

Posted

Photo numbers are mixed up.  I am a computer idiot.

 

Also, I do not see any way for differential fluid to get to the axle bearings.  They are lubed with grease and added through the hole in the outer wheel flange.  If differential fluid gets past the baffle, it is supposed to drain out the pipe tube.  

 

All of the above is based on my 1917D45 knowledge.

 

Bob Engle

Posted

Ken, 

    This cut away drawing is pretty accurate to how the 3/4 floating axle functions.  Standards have a 3/4 floating axle and Masters have a full floating axle so there are some differences.   Buick used a plug instead of a grease zerk in the side of the hub.  The grease would enter the hub, and it has to pass over a metal wall to get to the roller bearing.  The axle shaft would have been installed dry on the hub.  In the effort to put grease in using a zerk fitting, you can in the process get grease between the hub and the taper.  This is not good.  On the rear wheels, the hubcap should be clean inside.  So this makes the maintenance recommendation tricky regarding filling with wheel bearing grease.  The differential fluid is only supposed to be for lubrication of the gears and bearings in the central housing.  As long as the ring gear is in the fluid, you should be good, that is why filling to 1" below the hole is still OK.  The ring gear will pick it up and distribute it.  If the gear oil is too high, and you park with one wheel much lower than the other, gear oil will run between the axle shaft and the axle housing.  This will dilute the grease in the outer bearing area, but any excess is supposed to go out the oil drain tube.  At least it is a lubricant.  

Keep in mind that this system is no longer used for a reason.  I had axle and hub issues.  Worn keys in both the axles and the hubs.  I installed replacement axles with good keyways and I shimmed the key slot in one hub to prevent movement.  I used fresh silicone grease for the rear bearing when it was all apart.  I carefully installed the hub onto the taper dry.  This has to be done carefully to not get grease on the shaft or hub taper during assembly.   I will not be greasing my rear wheels thru that hole for fear of getting grease into the taper.  I figure with modern grease - I am probably good for 20,000 miles or more and then I will do a disassembly to repack the bearing.  Like you would do for a modern front wheel bearing.  Again synthetic grease in the front wheel bearings and I extend the maintenance requirements.  

 

    Point number 2.  There is a plug in the hub for the front wheels.  I will not be using that one either.  When I am ready for repacking the front wheel bearings, I will pull the wheel off like you do on a modern car, clean the bearings and inspect, then repack.  I will not be just squeezing grease in and filling a massive cavity with grease.  I don't have the same concern for the taper shaft here, but I find the plug a convenience that does not belong.  

 

Best to understand the theory and make your own decision to follow the 100 year old recommendations and determine if they are still valid and if they made the right decisions in the first place given that so much of what they did was experimental.  

Hugh

 

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  • Like 4
Posted

Hugh - 

Thanks for your explanation and recommendations. That pretty much takes care of my concerns.  I am going to leave the oil level in the differential 1-inch below the opening.  I saw a small drip out of the drain tube after the car was sitting all night but no oil on the brakes yet.  I am going to monitor that wheel for oil leaks but not going to worry about it any more.

 

Ken

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