Topic: Removing rubber dampers in rear hub (cush drive) - stop the madness

[tsflstb]

Is there a trick to it? 

I'm typing with both hands bleeding and will probably lose a couple of fingernails in the near future.  I've tried knocking them out from the back, screwing drywall screws in and pulling, clamping needle nose pliers on the inside and prying, and lots and lots of swearing.  I'm pretty sure stripping down hubs for eternity would be my punishment in hell.

On the plus side, I did get the wheel bearings knocked out.  If I can get these 'lil rubber bastages out I'll get to send my hubs off to the powdercoaters this week.  Then I'll get to walk around and say "send it off to the powdercoater" just like those awesome guys on tv.

[754]

Use a screwdriver a bit smaller than the hole, lubing  rubber point with soapy water or Ru-Glyde will help.

Work a bit of the side of the Hershey Kiss looking part into the hole, pushing down a bit and in . Pull scew driver out and push a bit more thru..repeat till 1/2 or better is thru. Eventually the whole end will just SKWOODGE  thru the hole, and you do the next ones..

[rhinoracer]

They should come out fairly easy, maybe they're stuck? Can you rotate them in their pivot?

Mine were stuck to the hub from all the brake dust, chain lube and whatever else gets in there. If they are try cleaning or spraying some silicone lubricant and wiggling them until they can be rotated by hand.

Then push them out.

[ttr400]

I presume we are talking 400F hub.  Yes they can be a real pain to get out.
Last time I did this was to cut through the rubber with a sharp chisel to get the centre part out then cut through the outer steel sleeve and pryed it out.
Years ago when I did it for the first time I burned the rubber and centre out. it worked but was major messy...

Kevin

[florence]

I tried that once, I got so angry with them, I poured petrol into the hub and set it on fire.  NOT recommended it didn't work properly.  It made a terrible mess and I still had to prise the bits out with a screwdriver.  I'm sure they could have designed it better but they last such a long time that the rest of the bike is nearly worn out by the time they need replacing.

[MRieck]

 Use a heat gun to soften the rubber.

[tsflstb]

Ever wished you'd just left well enough alone?  Easily the most frustrating task ever.



About 2 hours of work with every sharp and pointy tool I own today.  Got the center of one out, but the outer steel piece won't budge from the hub.  I'm working on it with a chisel and will hopefully have it out by November of 2032.  The other three are going to be just as bad.  The outer steel band is siezed to the hub and no matter what I do I can't get it loose.  I poured brake fluid on it and walked away for the night - don't know why but it made me feel better.  I kind of chuckled at the setting it on fire suggestion yesterday, but it makes perfect sense now.

I may have to just find another hub and leave the bushings in place - sucks because I've spent a ton of time carefully drilling and chamfering the holes to slip in 8ga spokes.  Has anyone else put the hub in the oven without removing these?

[MRieck]

 No way to put that in a press and push them out? Are they in blind holes??

[bwaller]

Yes Mike they are blind holes. The rubber is tough but once you have the center bush out I've used a die grinder and a carbide burr to just barely gnaw through the outer sleeve (without grinding into the aluminum) until able to punch the outer sleeve inward enough to loosen it.

I think this is one of those jobs that's impossible to make look pretty, but keep at it!

[tsflstb]

Not a completely blind hole, but they sit on a shoulder in the bottom of the hole so you can't press them out from the backside.  There's also a web running from the center of the hub right down the middle of the hole, so you can't put much direct force on them - hence the bleeding hands.



I'd love to see Honda's recommended method for getting these out.  For a consumable part, it seems a lot harder than it should be.  I'm guessing the service interval is more frequent than 32 years, so maybe they'd come out easier.

[tsflstb]

Take that, mf'ers.

Once you resign yourself to the fact you've got to beat the sh*t out of them, they do eventually come out.  The one on the right is a new one for comparison...he's a little scared.  I spent about 10 hours total on this and learned many new combinations of swear words.



# of Harbor Freight screwdrivers broken: 2
# of nice carbide-tipped Klein screwdrivers broken before I realized I shouldn't use the good one: 1
# of Harbor Freight chisels worn down to a nub: 1
Hit rate of hammer on chisel: 96%
Hit rate of hammer on fleshy parts of my hand: 3%
Hit rate of hammer on my sandal-shod foot: 1%
# of OSHA violations during this project: 6,442

[xjrguy]

For all you guys who have wrecked tools, burnt hubs and got hot rubber all over themselves, swore black and blue and cursed Honda, I have a really good way of removing these rubber bushes.
- Drill a 5mm hole down through the bush between the steel inner and outer sleeves. I chose 5mm because the rubber is 5mm thick between the sleeves.
- Open this out to 6mm and you will start to cut into the inner and outer sleeves.This is the important step as it prepares the pilot hole for the next step.
- Now drill the hole out to 6.5mm. The drill will follow the pilot hole right through to the back of the bush.
NOTE: Set your drill press up so that the drill will stop just after the end of the bush. The bushes are 30mm long, so set the drill to go 32mm deep. Don't go any deeper, otherwise you will drill through into the aluminium hub.
- I then used a Dremel fitted with a ball cutter to take the last tiny bit of the wall thickness away, but in hindsight, it would probably be better to drill again with a 7mm drill.
You will end up with a slight groove in the bore, but this is not a problem.
- Put a punch down through the hub from the brake lining side and punch through the rubber backing plugs (they should be replaced at the same time as the bushes). Locate the inner sleeve with the punch and (making sure that the punch is sitting vertical against the side of the metal web across the back of the hole) give it a good solid hit with a reasonable sized engineering hammer. The bush should drive out - mine did. They were tough to get moving, but they will come out.
No mess, negligible damage to the hub and hopefully, no damage to tools or fingers!
In the photos of the four removed bushes, the mangled one on the right was my first attempt when I was being very conservative with the drilling.

[Deltarider]

Why did you want to remove them?

[xjrguy]

They were replaced because they needed to be done - perished rubbers and rusted bores!
This hub is going on a classic racing machine so everything has to be spot-on.
I posted this information to help others out who might need to replace these bushes.

[NobleHops]

Xjr that is a great technique, thanks.

I got my ass solidly kicked by that, ended up with my tail between my legs at my machinist's. Next time I'll ignore them, they are to thin to do much good as dampers, and aren't visible behind the sprocket anyway.