Topic: I still can't get the f!@#$%g rotor off!

[Terry in Australia]

Well folks, if you've read my earlier post, you'll know that I'd made several attempts to remove the alternator rotor from my beautiful CB750F2 so as to repair the starter clutch, as it's making some rather unusual noises.

Anyway, I was berated by all and sundry in this forum for my ineptitude, in my unsuccessfull attempts to remove the recalcitrant rotor, and such was the high state of ridicule that Mike ("The Good Samaratin") Rieck went to the trouble of sending me a shiny new factory Honda rotor puller, which arrived today, woohoo!

As soon as I saw the box I raced out to my garage, tore it apart with fevered frenzy, (thanks Mike, I love those CNC alloy billet valve caps too!) and launched it at my unsuspecting rotor! Holding the rotor with the recommended extra long screwdriver, I tightened the puller into my rotor, and gave it a tap, nothing. So I gave it another tap, nothing. So I gave it another tap, nothing.  I tried to tighten the tool a tad more, but nothing happened. I then tried to tighten the tool a tad more, but nothing happened. So I gave it a tap, nothing.  I trained my heat gun on the tool and centre of the rotor hub until it was almost too hot to touch, and then gave the tool a tap, nothing. I tried to tighten the tool a tad more, but nothing happened.  So I gave it a tap, nothing. Hmmnnnn.
 
This went on for awhile, until the tool started to turn, woohoo again! Then I realised that the tool was turning, but the rotor wasn't moving, I'd managed to strip out all of the internal thread! Lovely. Tomorrow I'm going to try a conventional two or three claw heavy duty rotor puller, I don't care if it marks my rotor as my rotor is now toast anyway. Luckily I don't need this bike as a daily rider, or I would have reached for a box of matches and the keys to the fuel cap, ha ha! (or should that be boohoo?) Cheers, Terry.

[oldbiker]

Hi Terry, I realise all that soft living in Sunny Australia has softened your muscles, still never mind I will try to help. When I had a similar problem with my cb400f, I made a slide hammer to do the job. A 12" lenngth of 1/2" steel with a stop at one end and an adapter to fit the thread in the rotor at the other makes the main part. Then a 3" length of 3" diameter steel bored to slide on the rod makes the hammer part. screw it all the way in and then one or two good thumps usually shifts the tightest rotor.

[mcpuffett]

it might have worked  but terry has no thread left on the inside of his rotor now   hey terry if the 3 legged puller does'nt work and your rotor is toast  can you not weld something on to help pull it off mick.

[Robert]

Now that the thread is gone, it won't help much, but I'll post anyway.
The thing is rotor pulling has little to do with muscles or force (if applied continuosly) but with impulse, impetus, momentum.

The change in momentum, called the impulse, is equal to force times the change in time.

The crank shaft has to be prevented from moving only the slightest tad as this will weaken the impulse.
It is not enough to apply break and gear (numerous dampers in rear wheel, clutch, prim.shaft)

The rear axle if (threading/size correct) can work sometimes, but actually it is too long and the material it is made of is too weak , so it will twist (torsion) and eat up the impulse. Also a 20+ year old axle most often is in bad condition, the end in not 100% planar anymore, the thing will tilt, ruin the threads, the rotor will be unimpressed. Use a rotor puller, or a hardened bolt (made of steel) of the correct size.

So how does it work. Apply WD40 or similar to the opening of the rotor, and make shure it is clean.. Screw in (to screw it in, use something that has no moving parts, no ratchet, a T shaped tool is good) the proper tool (rotor puller/hardened bolt) until it sits firmly but not too hard, as to not to  ruin the threads.
Use a heavy plastic sledge and firmly and straightly pound on the T.


If threads are gone, a three legged puller to build up tension between crank shaft and rotor evtl. in combination with temperature (ice spray on crank shaft/MINI acetylene torch on rotor) might do it, but it has to go fast, and you have to be careful to not set that thing on fire!

[MRieck]

Well that's a bummer. In hindsight weeks of soaking with some type of penetrate would have been a good idea. I always apply some moly grease to the puller threads to help prevent galling. I'd put some real heat to that thing too. Boy Terry that bike has fought you tooth and nail!!

[Quail "Owner of the comfortable k8"]

When all standard wenches fail, the fire wench always works.  (Oxy torch)

[mick750F]

   Well Terry, it looks like you're down to the last option....blasting. When it's all over just sweep up any salvageable parts and send them to me. 
  I wish I could offer you a solution but I think it's all been covered here. Perseverance lad...you will beat this pesky rotor and send it to Rotor Hell where it belongs.

Mike

[Terry in Australia]

Typical Ozzy tut tut tut! the languagre is excesive!.....Get it hot, then pull once it's off, put it in the bin.....Then put another shrimp on the BBQ have a beer..... strooth! ......I had a word with queen Liz and she said keep the language down! I told her it's allowed he's an Ozzy and it's OK they all do that!

Pommy Wanker! Ha ha, just kidding, you guys are great, ( ) but I fear that none of you have any advice that will make a shred of difference, I just wanted to share my pain. I've tried all the various potions, penetrating oils, greases, lemon juice, wacking it with a bag full of goldfish, human sacrifices at midnight while dancing the rumba dressed as a school boy with an effigy of Michael Jackson strapped on my back etc, and none of these things worked.

I'm quite sure when I eventually get the rotor off I'll find that a PO has previously welded the bastard on, this was the same bike that had two joining links in the drive chain with the pins welded over but no clips, an engine full of silastic and a score in #4 cylinder caused by the wrist pin when the PO left the circlip out, and this is just a couple of examples. As Mike says, I've had to fight this bike tooth and nail, it's almost like it really didn't want to be restored, but maybe I'm just imagining things?

Anyway, as Mick Puffett has suggested, I may even weld a local pattern (home made) puller to the rotor to get the sucker off, using the short hydraulic ram out of my 10 ton porta-power as the driving force to crack it off. If this doesn't work, I've got another complete F2 crank and rotor, and when I split the cases to get them powdercoated, I'll swap them out. Cheers, Terry.  

[Quail "Owner of the comfortable k8"]

Terry

Fire is the answer to everything.  If you tried fire it just means you did not use enough.  I love fire.  Fire loves me.  Afters years of welding I have hundreds of Fire Kisses on the old body.  Fire created that rotor and fire will fix it too.  Did I mention I love fire.

Terry

ps  I took your advise and started to collect ads for bikes like mine just in case I ever loose it.  There is an insurance adjuster out there that hates you.

[kghost]

I have a suggestion if the crank is out of the case.

What you could use is Freon, LP Gas, etc. Heat up the rotor, put the puller on and apply tension. Then give the crank a blast of cold gas. I suppose if theres no gas lots of pitchers of ice cold water would work.
  Might be the way to expand the rotor and shrink the crank.

Other option would be to heat the crank and rotor up to about 350 degrees in your oven then put the crank end in a bucket of cold water. The water will pull the heat out of the crank contracting it while the rotor remains hot and expanded. Put the puller on the crank with some tension, before you stick it in the oven

[Terry in Australia]

Terry, put down your matches and get back on your medication old mate, you're quite probably certifiably insane. Give Robert some while you're at it, he's either insane, or high, or both.

Kasper, at what temperature do you think my crank will start to distort? Hmmnnn, I'm starting to think Glenn should rename this forum "Crackpot theories for caring psychopaths", ha ha! Cheers, Terry.

[kghost]

Well, its steel and shouldn't melt until well over 700 degrees. Shouldn't affect the temper either.

If its heated evenly I wouldn't think 350 degrees be an issue. The oil temp in these engines can run up to 200-220 degrees.

[Hop on a Honda]

Dear God in Honda Land.
It is with regret that I have to announce a terrible mistake has happened to a dear friend of mine who has honda hydralic fluid in his veins for blood but the unthinkable has happened.
Hi fuk$%&ing rotor has married his crankshaft and will not divorce it at all. How does this sinfull occasion happen whens't in the eyes of our beloved Honda Deciplies it should have nebber happened in the first place. Obviously a dirty condom has been used.
We have offered all kinds of pennance and even giving up the sacred sabeth of having a beer with ya mates on Friday night to discuss Hondas and their relitives. But, to no avail.
I sugested that we surround the said'eth coil with a kilo C4 and let it burn in hell but that could be a administration problem for the undertakers as Terry may wish to cry. Dear Honda help Terrry get his rocks off and drop the bloody crank shaft on its end for him and get the blood job done asap. We will never hear the end of it if you don't!!
Dave  in sanity.

[Terry in Australia]

Dear God in Honda Land.
Dave  in sanity.

It's OK folks, Dave is a genuine Aussie war hero who took a couple of projectiles in the name of freedom and to deny the expansion of Communism (remember that? That's what we were all frightened of before Islam took over) in SE Asia, so he's got an excuse, ha ha!

Dave will be visiting the US in a week or so, with a lot of other like-minded American Vietnam vets, so if they're visiting your town, stay indoors, don't make eye contact, and lock up your grand-mother's, ha ha! Cheers, Terry.

[Chrisboden]

I don't know about applying LP or Freon, either of those could ruin your whole weekend and cost far more then a very cheap solution.

Go to the same welding gas supplier where you get your Oxy/Ayl/CO2/Argon/Etc and bring a STAINLESS STEEL (not glass) thermos with you.

Ask them to sell you a liter of Liquid Nitrogen, it's cheap.

DO NOT PUT THE LID ON THE THERMOS!

And even more importantly, don't let the Liquid Nitrogen on your skin, you won't forget it if you do. It's far colder then you can imagine, and will *remove* body parts in short order. This isn't like dry ice (solid CO2), which will just burn you. Dipping a finger into liquid Nitrogen will freeze it solid instantly, and then it will fall off, hit the floor and shatter like glass.

It's fun to try with a banana.

How, wearing proper gloves, clothing and face shield, pour this on your shaft. If you put a micrometer on it you can WATCH it shrink, signifigantly


Just be careful with this stuff, it's dangerous, but it's FAR safer then doing similar tings with LP/NG or Freon.


Your friendly neighborhood science teacher.
Duck

[Quail "Owner of the comfortable k8"]

Safety note.  freon and heat = fozzine gas = death

[Terry in Australia]

Thanks guys, I think it's time for me to back away slowly and try not to make eye contact, the loonies have left the asylum and they're all hanging out here! Ha ha, Cheers, Terry.

[kghost]

Jeezz, I wasn't suggesting you sniff the fumes.