Leaking rear end

51Hudson

Hello everyone, as the title says my 51 Hudson rear end likes to leak and I'm tired of it leaving stains on the driveway. So I want to make this my winter project and living in the snow belt of Ohio I'm sure it won't be long before it snows here and it is time to put the Hudson away. So I figured I would get a head start and hopefully get some tips and seals ahead of time. I see that rock auto sells the pinion seal along with the pumpkin gasket but where can I find the outer seals for behind the rear brakes? Also does anyone have any tips to make this job easier? And another thing, when I take the rear pinion nut off and replace the seal, do I have to replace anything behind the nut? The reason I ask is because my dodge ram when you replace the pinion seal you are suppose to replace a crush sleeve, is that the same for the Hudson? Thanks for your help and I'm sure I might think of more questions later about fixing my leaking rear end.

Park_W

The outer rear axle seals are NAPA 17310.  Use care in pulling the axle shafts out . . . don't let them drag on the inner seal.  Hardest part of the job these days seems to be finding a good puller to get the drums off.

When replacing the pinion seal, I don't recall that any crush washer or sleeve is involved.  Just get the nut on tightly, to avoid the bearing's running too loose.  When it's buttoned up properly, the pinion shaft should be a bit hard to turn,

[Deleted User]

use a good torque wrench when tightning the pinion nut, and do not go above specs. that way if there is a crush sleeve it should be back to proper crush.

51Hudson

Ok thanks everyone. I didn't know there was inner and outer seals to the rear end. I guess my inners are bad too as I see gear oil on the back of my backing plates. I might be interested in those inner seals from Ken u-tx. Thanks again

51Hudson

Does anyone have the part numbers for the pinion seal along with the differential cover gasket from Napa?  Also if I am replacing the differential cover gasket, do I have to mess with the shims or do those all stay attached to the pumpkin?

lostmind

The outer rear axle seals are NAPA 17310.  Use care in pulling the axle shafts out . . . don't let them drag on the inner seal.  Hardest part of the job these days seems to be finding a good puller to get the drums off.

When replacing the pinion seal, I don't recall that any crush washer or sleeve is involved.  Just get the nut on tightly, to avoid the bearing's running too loose.  When it's buttoned up properly, the pinion shaft should be a bit hard to turn,

 

 

/openforum.hetclub.org/discussion/166349/proto-hub-drum-puller#Item_1  " Parts & Pieces" section

 

Park_W

If it's a '51 type axle, removing the differential assembly (AKA pig, pumpkin, etc.) doesn't involve the shims or other internal parts.  The whole thing comes out in one chunk.  And it's heavy!

Since it's a Hudson-made axle, you may not find the big gasket at a local parts store.  But the club's "parts guy," Dale Cooper in Cincinnati, has them.  The NAPA pinion seal number I have is 17720,

russmaas

We have the inner and outers $56 for the set of 4. 21st Century Hudson (the other "parts guy" lol_)

51Hudson

If it's a '51 type axle, removing the differential assembly (AKA pig, pumpkin, etc.) doesn't involve the shims or other internal parts.  The whole thing comes out in one chunk.  And it's heavy!

Since it's a Hudson-made axle, you may not find the big gasket at a local parts store.  But the club's "parts guy," Dale Cooper in Cincinnati, has them.  The NAPA pinion seal number I have is 17720,

 

Thanks for your help.  Yes it is the Hudson made welded on rear diff cover axle.  It is good to know that I won't have to mess with any shims or loose any.  Oh and it looks very heavy just looking at it.

51Hudson

We have the inner and outers $56 for the set of 4. 21st Century Hudson (the other "parts guy" lol_)

Thanks for you help too. I already bought the seals from Ken U-Tx but I will keep you guys in mind if I need anything else in the future. Do you have a website?

51Hudson

Hello again. Im finally getting around to fixing my leaking rear end. I have another question to ask. What kind of gear oil should I put in it and what weight? I know it came with 90 weight when it was new but what is best for it now? Thanks for any help.

RL Chilton

The same, 90W.  

51Hudson

Ok. Thanks. I have looked before and haven't found straight 90 at any of the stores. I was hoping I could use something like 80w90 or something close to that.

51Hudson

Hello. I got another question for all of you. I just got out the axle shafts and if I replace the bearing, do I have to re-shim the rear end? Thanks

railknight

Brad Penn produces their "classic" GL-4 SAE 80W-90 gear oil for older transmissions.  Their claim is, "it's designed to be used with yellow metallurgy (brass, bronze and copper). 

Another gear oil that claims to be safe for "yellow metals" is Royal Purple Max Gear Synthetic.  They produce a straight 90 weight synthetic gear oil in addition to other gear oil weights. 

Dan 

51Hudson

> railknight > Brad Penn produces their "classic" GL-4 SAE 80W-90 gear oil for older transmissions.  Their claim is, "it's designed to be used with yellow metallurgy (brass, bronze and copper).  Another gear oil that claims to be safe for "yellow metals" is Royal Purple Max Gear Synthetic.  They produce a straight 90 weight synthetic gear oil in addition to other gear oil weights.  Dan 

 

Thanks so much for your help.  I will try and find Royal purple.

51Hudson

> Ken U-Tx > Did you press the bearings on? I find that they need a slight press fit onto the taper, otherwise, when you initially set them up, you find they have no endplay, and probably will be pre-loading with the original shim pack. If they are just tapped on they sit out too far on the taper. These bearing's inner races can safely be pressed to @ 0.002- 0.003" interference fit. Since the taper is 12:1 , if you press them on to a 0.002" interference fit, they will move inwards 0.024", and at 0.003" interference fit they will move inwards 0.036". I try to center the axle-shafts to the thrust block is centered on the pin in the differential. These thrust blocks have been known to fracture and fall off the pin, resulting excessive axle shaft end-play. Also, look at the hardened steel thrust buttons on the inner ends they should not show excessive wear or damage.

 

Ken, once again thank you for all your help and knowledge.  I have not done anything yet to the bearing and after I pulled the shafts I'm thinking on just reusing the old ones.  They still look pretty good.  And plus I could save my new bearings for a rainey day.  Also after seeing what has to be done to get the correct play, I don't know if I'm up to the task.  lol  Thanks again

51Hudson

Oh I forgot to say earlier, when I got it all apart, all the gears looked in  great shape with no wear on any of them.  Hopefully with a few new seals, all will be good again with my Hudson.

Uncle Josh

Well, I haven't seen where it's leaking.  Is it the pinion or the wheels.  Hudsons have a vent on top of the left axle about half way between the punkin and the wheel, with a little cover that has a nasty habit of plugging up with crap,   it needs to be cleaned periodically usually by turning it and cleaning up around it.  If these get plugged up, the rear end will build up pressure and push oil out of the pinion.

51Hudson

Well, I haven't seen where it's leaking.  Is it the pinion or the wheels.  Hudsons have a vent on top of the left axle about half way between the punkin and the wheel, with a little cover that has a nasty habit of plugging up with crap,   it needs to be cleaned periodically usually by turning it and cleaning up around it.  If these get plugged up, the rear end will build up pressure and push oil out of the pinion.

Hello, my axle was leaking out pretty much all the seals, including the pinion, the pumpkin, and by the wheels.  I did check that vent this past summer after reading another topic about a leaking rear end and my vent turned out fine.  I guess things start to leak after 60 years and need changing.

51Hudson

Wow. I just looked up royal purple 90 weight and they make you buy 5 gallons of it for a nice price of $364. Wow. I guess I will buy some royal purple 80w90 or close to that for a little cheaper.

railknight

I bought a quart of Royal Purple last year at the local Napa dealer just to use to top off my Super Wasp transmission when needed.  I believe it was around $30.00.  Yeah, the stuff ain't cheap.  In fact, even the guy behind the counter at Napa was surprised on the cost.  

If you Google "yellow metals" and  "gear oil" you'll be directed to all sorts of vintage car, truck and tractor clubs that discuss this issue of present day gear oils being harmful to the yellow metals in older transmissions and rear axles.  There are numerous suggestions on what is or may be a safe gear oil to use.   

Dan

51Hudson

Thanks everyone for your help.  Today I got all the seals changed out and most of it all back together except for the drivers side axle.  I ran out of time today so it will just have to wait till next weekend. Most of those seals where a pain to change out and even took some creative thinking on how to get them out.  Meanwhile tonight I ordered some Royal Purple 75W-90 from online so I will have that in time for next weekend.  I even ordered enough to change the oil in the transmission and the overdrive.

51Hudson

Ok everyone. I finished up everything today and put some royal purple in and lowered her down. Everything sounds good and now I'm on my next project. Thanks again.