Rear axle leaking
 

1940 Deluxe…. One of my rear brakes is completely soaked with gear oil from the differential. I drained the diff, and I got the drum off and now I’m not sure how to replace the axle seal. Can I pull the axle out? And if so, how? or do I have to take the banjo differential apart? I was assuming that the axle seal would be accessible from outside, but now I’m afraid it is a much bigger job.

Re: Rear axle leaking
 

Yes, it’s a much bigger job, too complicated to explain here, but easy enough for anyone who knows what a box wrench is used for. Best instructions for your job can be found in an old MoToRs Manual that covers your year. These can be found in decent condition for about $20 - $30 from online book dealers.

Re: Rear axle leaking
 

This older thread might be of some help to you.

https://www.fordbarn.com/forum/showt...+housing+seals

Re: Rear axle leaking
 

There are two seals - one for the axle and one for the drum and associated bearings. If you're seeing gear oil, then you surely have an axle seal issue. As noted above, it is a big job to replace this inner seal as you have to pull the banjo housing for that side off the car . . . which means you have to compress the spring, etc..

This can be done with the rear axle in the car, though I would pull the whole rear end and do both sides.

It is a classic case where the seal costs little of nothing, but the labor needed is a bugger!

Re: Rear axle leaking
 

I believe Mart has a video doing one side with banjo in the car. Yep, big job, including compressing the spring. (which scares the heck out of this amateur)

Mart, if you see this and I am remembering correctly, can you post a link to your video?

Re: Rear axle leaking
 

Thanks for the info! I’ve learned a lot this morning. I had not heard of the Motors auto repair manual, I’m going to buy one. I read the old thread, I’m going to take Kube’s advice there and do the whole job, not use a quick-fix seal. He says it’s not that hard…

And I found the section in my green “shop manual / service handbook”. It says the differential gear is forged onto the axle without a spline, so good thing I didn’t try to remove the axle with a slide hammer :) It also says “As considerable special equipment is required for disassembling and reassembling rear axles, it is recommended repairs should be performed only by competent repair men having the necessary equipment.”

Well, Ford38V8 says I just need to know what a box end wrench is, and my wife bought me a coffee mug that says, “Ready, willing and vaguely competent”, so I think I’m ready to go! Haha, this must be why I bought an old car.

Re: Rear axle leaking
 

Google, ford banjo axle rebuild, and you will find a number of videos that I think will be helpful.

Re: Rear axle leaking
 

I clicked on the link that deuce lover posted regarding an earlier forum topic pertaining to the "quick fix" internal/external axle seals...
I am very familiar with this type of seal, I made a contribution to the 10'13-19 topic when it was active.
To recap, I have used this slip in type of seal since the 1950's, we always used a seal that was made by named National. I had several in stock which I used the last of in the late 1960's, they are still in my rear axle...
Replacing the inner axle seals is a huge job requiring almost a complete tear down of the rear axle assembly.
As I recall the Columbia axle required a larger seal, which has been out of stock for many years. The external slid in seal did a perfect job of sealing the axle thereby eliminating oil leakage into the hub.

Re: Rear axle leaking
 

I'd strongly advise&suggest as far as oil seals are concerned see if you can find,locate, search&seek the O.E.M/ORIGINAL FORD oil seals, as these are metal cased leather lip&are better suited to older style lubricants&metallurgy.They also DON'T leak like modern neoprene rubber oil seals, the part numbers are: B-4245 for inner axle oil seal that fits/sits inside the axle housing, 78-1175, which fits/sits inside the brake drum, this's the outer oil seal.

Re: Rear axle leaking
 

done a few of these seal replacements, not that hard once the spring has been stretched to remove the shackles, made a tool out of junk fence rod, a washer and a small sleeve to reinstall the seal, my wagon was don 30 years ago, my tudor was done over 40 years ago and neither leak

Re: Rear axle leaking
 

I have lots of older leather type seals that seem to be dryed out. Can I revive them with lubrication of some sort?

Re: Rear axle leaking
 

Tim,
ALL felt washers&leather oil seals require soaking overnight(24hrs),
To soften up the leather, NEVER EVER install them dry because they'll wear the shaft,
&Sometimes cause a groove where the oil seal fits/sits, negating the use of a C/R "speedie sleeve"/NATIONAL " redi sleeve"&epoxy resin applied to the groove,
Then the redi/speedie sleeve slides over the shaft, the the oil seal sits on the redi/speedie sleeve, this restores the surface to as new condition.

Re: Rear axle leaking
 

I'll be around when you tackle this if you need some help. Private message me anytime.
Where did your wife find that mug? I so want one :)

I have had very good fortune with new seals. However, old leather seals, when soaked for a day or two in oil, will also work just fine.

Re: Rear axle leaking
 

there is an after market seal that slip over the axle & it works.some one on the barn had them may be he still does.

Re: Rear axle leaking
 

Hi Kube, thanks for the offer! I love your book by the way, it’s super useful. I highly recommend the mug. Here it is on Zazzle. There is nothing like a friendly hippo with a hammer to make you feel like you are making good decisions!

https://www.zazzle.com/vaguely_compe...72923157221901

Re: Rear axle leaking
 

CR or Chicago Rawhide seals were a standard in the industry back in the day. Old NOS parts need to have solid leather remaining in the part. If the leather has started to decompose from poor storage then I wouldn't be excited about using it. The seals were made to run in mineral oil so soaking them in the recommended oil used for the unit assembly is the way to go.

The old banjo rear axle design only allows seal access from the inside of the bell. Which ever housing needs the seal will require that side housing to be removed to replace the seal. Leave everything else in situ that doesn't require removal. Take care to note condition of the inner bell gasket or gasket stack. A person needs to avoid having to readjust the carrier & gear preload and backlash if possible. It gets a lot more complicated if the gaskets fall apart.