Author Topic: Wheel Hub - How to dismantle? (The Mummy)  (Read 336 times)

0 Members and 1 Guest are viewing this topic.

Offline donnh

  • Member
  • *
  • Join Date: Dec 2018
  • Posts: 16
  • Location: Preston, Washington USA
Wheel Hub - How to dismantle? (The Mummy)
« on: 01 May 2020 at 03:52 »
Since I'm waiting for the tank and seat I'm moving on to the wheels. There is even tape wrapped inside the rim.


My question is how to get the hub apart?? I managed to get the caps off but now what?


Thanks in advance,
Donn

Offline cardan

  • Master Member
  • ****
  • Join Date: Jul 2007
  • Posts: 1015
  • Location: Adelaide, South Australia
    • Leon's Vintage Motorcycle Page
Re: Wheel Hub - How to dismantle? (The Mummy)
« Reply #1 on: 01 May 2020 at 12:44 »
Hi Donn,

The large part with the 6 holes is the bearing cup, and this is screwed directly into the hub. You have a lovely clean example that has not been hit with a pin punch, and you should keep it that way! If you don't have an appropriate pin wrench (most of us don't) you can make one from a bit of steel plate with a couple of nails to act as pins to engage with the holes in the bearing cup. The cup with the exposed thread is the adjustable one, and in principal shouldn't be tight, so do some WD40/penetrating oil/soft heat on hub in the usual way. The cup on the other side is fixed; it also unscrews but I'd leave it where it is unless absolutely necessary as it is mostly done up dead tight and is sometimes difficult/impossible to loosen.

As you will see, these Douglas hubs (based on the Chater Lea design) are a bit weird in that the axle is machined to include the bearing cones. You'll see what I mean when you unscrew the cup.

Cheers

Leon

Offline cardan

  • Master Member
  • ****
  • Join Date: Jul 2007
  • Posts: 1015
  • Location: Adelaide, South Australia
    • Leon's Vintage Motorcycle Page
Re: Wheel Hub - How to dismantle? (The Mummy)
« Reply #2 on: 01 May 2020 at 12:48 »
Also, beware the axle nuts: these are BSCy 20 tpi, NOT UNF.

Leon

Offline donnh

  • Member
  • *
  • Join Date: Dec 2018
  • Posts: 16
  • Location: Preston, Washington USA
Re: Wheel Hub - How to dismantle? (The Mummy)
« Reply #3 on: 01 May 2020 at 22:46 »
Here is my story in pictures...
I took a piece of copper and drilled a hole and placed it over the hub and pounded it with a hammer. This gave me a nice pattern to make a tool.


Next drill a few holes



I used some #6 screws I had with nuts to keep them from twisting. They are held down using the cap and nut from the axle.





Apply heat and penetrating oil.


Ohh Ohh, this doesn't look good


Nope,



So, I'm giving this a break for today.
Question... Am I on the correct side of the axle? I was applying a lot of torque before the tool broke. Should I be on the other side?

Is it possible to purchase / borrow the correct tool?

Donn




Offline cardan

  • Master Member
  • ****
  • Join Date: Jul 2007
  • Posts: 1015
  • Location: Adelaide, South Australia
    • Leon's Vintage Motorcycle Page
Re: Wheel Hub - How to dismantle? (The Mummy)
« Reply #4 on: 01 May 2020 at 23:26 »
All good except the result!

Your tool is very lovely, but the screws are clearly not up to the task. Cut them off shorter so they can't bend. I use bright nails because they are high tensile, hammer them though the plate, and only silver solder them in if I get the hole size wrong. But your screws should be enough.

The cup has just one continuous thread on the outside, so the handedness is what you see. I assume the lock ring screwed off like a usual RH thread.

Soak the thread in your favourite penetrating oil. Heat the hub with your heat gun. Set your tool up and clamp it in place. Then give it a belt with a copper hammer! (Sorry Doug, I can sense you wincing, but this is how us amateurs do things...)

I doubt there is an exact tool available for this job. An adjustable pin wrench would not be as good as the tool you have made. Let's face it, this thread is meant to be finger tight. 100 years of rust...

Good luck.

Leon

Offline Hutch

  • Senior Member
  • ***
  • Join Date: Nov 2012
  • Posts: 251
  • Location: Queensland, Australia
Re: Wheel Hub - How to dismantle? (The Mummy)
« Reply #5 on: 02 May 2020 at 01:30 »
Donn and Leon,

The adjustable cup on 2 3/4 hp bikes are left hand thread. Fixed cup is right hand thread, (some have it stamped on them, or at least the dust caps do). I assume 4 hp is the same, but it would pay to check as Leon suggests, to see what you have on your bike.

Leon, your  idea of high tensile nails sounds like a good choice for the pins on the wrench, grind the point off and using a  minimal amount of protrusion. I have cut up surplus scrap Douglas 11g spokes for the pins as they are almost exactly the right size. Most of the time they work well, but I have found they shear off sometimes with hubs that are a bit more difficult than usual to get apart. I have found that the quality of the Douglas spokes is variable tho' and some are quite soft and don't work well as pins.

I have had trouble getting some hubs apart but the application of heat (using a propane torch in my case - use with extreme care!) and penetrating oil and patience seems to you get there in the end. Watch out that you don't set the oil and grease in the hub on fire with the application of too much heat as things can get exciting in the shed!! :-) ...cannot say how come I know that......(BTW I would not apply heat with a propane torch to a hub with good Nickel plating as it would ruin the plating, I have only applied heat to hubs that were going to be re-plated and had resisted all other attempts to get them apart).

I have in general found that the external appearance of hubs has been no indication of how hard it is to get apart or the condition of the insides. Some good looking ones have been very difficult to get apart. Some very rusty ones have come apart easily and the insides have been in usable condition.....

Also, the adjustable (left hand thread) cup has usually been easier to remove than the fixed (right hand thread) one (...they can be a right pain in the ....)

When you get the cups out you will probably wonder what was making it so difficult for them to be removed!!

Best of luck,

cheers

Ian

Offline eddie

  • Master Member
  • ****
  • Join Date: Mar 2006
  • Posts: 1509
  • Location: Hampshire, UK
Re: Wheel Hub - How to dismantle? (The Mummy)
« Reply #6 on: 02 May 2020 at 06:57 »
Donn,
           Repeat your attempt to unscrew the bearing cup, but don't put locknuts between the bar and the bearing cup. Just place the bar over the axle, insert the 6 bolts (each with a loose nut), slide the retaining plate on the axle and nip up an axle nut to keep everything in place. The axle nut and plate will now ensure the bolts are engaged to full depth. Lightly nip up the 6 nuts to keep the bar tight against the end of the bearing cup. Applying leverage should now shift the bearing cup - the worst it can do is sheer the 6 bolts (rather than bending them over).

   Regards,
                  Eddie.

Offline donnh

  • Member
  • *
  • Join Date: Dec 2018
  • Posts: 16
  • Location: Preston, Washington USA
Re: Wheel Hub - How to dismantle? (The Mummy)
« Reply #7 on: 02 May 2020 at 15:59 »
Quote
"The adjustable cup on 2 3/4 hp bikes are left hand thread. Fixed cup is right hand thread, (some have it stamped on them, or at least the dust caps do). I assume 4 hp is the same, but it would pay to check as Leon suggests, to see what you have on your bike."

This might be my problem..... I'm working on the side with the RH threads which would be the "fixed cup". The other side is the LH threads which I learned the hard way trying to take off the cap - and destroying it.

Another clue: while trying to remove the cap with the LH threads (in the wrong direction) the axle became very tight, obviously I was probably tightening the hub (arrgh). My next attempt will be to loosen the hub on the side with the LH threads.....

Oh, about the nuts on the top and bottom of the tool... despite my best attempts, the holes still didn't line up perfectly so I had to enlarge the holes. My reasoning for the nuts was to keep the bolts from "tilting" in the hole. Not ideal, but it seemed to work. I agree, I probably had too long a length which allowed bending.

I'll report back! Thanks for the help!

Offline donnh

  • Member
  • *
  • Join Date: Dec 2018
  • Posts: 16
  • Location: Preston, Washington USA
Re: Wheel Hub - How to dismantle? (The Mummy)
« Reply #8 on: 02 May 2020 at 18:09 »
Ok, I admit.... I bashed the S*&t out of the cover. After cleaning it I see the "LH" marking.


The RH side is pretty good.


I followed Eddie's suggestion and HEY! It came off!


The good news is that upon first inspection everything looks usable, now I need to get some rims and spokes. Any thoughts... stick with clinchers or a modern rim?
I presume the rear wheel is the same as the front, that is next.

Thanks for all the help!!