Author Topic: Bessie, my first rebuild: 78 CB750F3 (Back on the road 2016-05-12)  (Read 70320 times)

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Offline SOHC Digger

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Re: My first rebuild/restore ever: 78 CB750F3
« Reply #25 on: December 06, 2010, 09:39:08 PM »
And as we approach the realm of shattering impact driver bits, I'd like to remind you to wear safetly glasses and gloves.  Just saying, safety first.  Removing bits of iron embedded in flesh or eyeballs doesn't feel good.

Offline tango911

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Re: My first rebuild/restore ever: 78 CB750F3
« Reply #26 on: December 07, 2010, 06:35:39 AM »
just a thot,  i had the exhaust screws really stuck,  but i put a wrench on my driver and used leverage to break them free as i pushed in really hard.   
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Offline wohali

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Re: My first rebuild/restore ever: 78 CB750F3
« Reply #27 on: December 08, 2010, 07:57:51 PM »
OK - got the screws out! ;D  Even after wedging the engine in a corner of the workshop and destroying my hand, the impact driver wasn't helping. (I hit things with a hammer like...forgive the expression...a retard. Zero physical hand-eye coordination at that level. I can't even catch a baseball. My hand that was holding the driver, while wearing a glove, is black and blue now.)

I ended up resorting to my Lisle Super Outs, the smallest two in that set. Did a teeny bit of cleanup of the head with a 1/8" drill bit - the head was so soft it didn't take much to clean up - whacked one or the other in depending on the hole size, applied a little torque and presto. Wish I'd done that first. These screws can't be that hard to find...

Now I'm scouring the Toronto area for the clutch removal tool. I may buy the Z1 part but my time is at a premium...what I don't get done by next Friday, will probably have to wait until February :( Also Hondaman's text is wrong, he says the tool is $8. I only see it on Z1 Enterprises' website at $42... :o  :( :'( 

Offline SOHC Digger

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Re: My first rebuild/restore ever: 78 CB750F3
« Reply #28 on: December 08, 2010, 08:01:59 PM »

Offline wohali

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Re: My first rebuild/restore ever: 78 CB750F3
« Reply #29 on: December 08, 2010, 08:03:30 PM »
Thx - still at least a week's wait for it to ship to Canada, get through customs, etc. Going to call around to local shops tomorrow and see if I can't buy local, or just borrow one for a few hours.

Offline wohali

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Re: My first rebuild/restore ever: 78 CB750F3
« Reply #30 on: December 09, 2010, 08:18:26 AM »
Woo - bike shop near me will loan me theirs for a $20 deposit!

http://fsmotorcycle.com/ for any GTA'ers who may need one in the future...

Offline wohali

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Re: My first rebuild/restore ever: 78 CB750F3
« Reply #31 on: December 09, 2010, 07:39:13 PM »
Clutch off! Plates look a bit worn, I'll see if it's salvageable or if I need a new set later.

There must be a special circle of Hell for whoever designed those engine studs.  >:( I got 5 of the 16 out, and in the process ripped the internal threads clear off of 2 locally obtained M8-1.25 nuts, and wrecked the outside of 2 of the original head nuts (augh!!!) At least it's a standard size and I should be able to obtain more in the future...

Tomorrow heading out to get a huge handful of M8-1.25 nuts and will remove the remaining studs, which should let me invert the engine so I can get the last bolts out and split the sucker. Not far now! :)

Any tips for stud removal other than countertightening 2 (or more?) nuts on the threads, then vice grips and gank as hard as possible? I have a new set coming in the mail, so I don't really care if they get ruined in the process...
« Last Edit: December 10, 2010, 04:14:11 PM by wohali »

Offline SOHC Digger

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Re: My first rebuild/restore ever: 78 CB750F3
« Reply #32 on: December 09, 2010, 07:52:50 PM »
Believe it or not, I had good success using the impact driver on the studs.  Lightly countertighten two nuts so that you can slip a socket over both and then use the driver.  You shouldn't have to be nearly as violent as with the last bolts you fought.
« Last Edit: December 09, 2010, 08:07:44 PM by SOHC Digger »

Offline brandEn

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Re: My first rebuild/restore ever: 78 CB750F3
« Reply #33 on: December 09, 2010, 08:03:53 PM »
Set the top case in a 350 deg oven for ten minutes will help. I was working on my studs in the kitchen on the floor with my case wrapped in an old blanket!

Offline MCRider

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Re: My first rebuild/restore ever: 78 CB750F3
« Reply #34 on: December 09, 2010, 08:24:14 PM »
There is a tool for stud removal. Should be local at Sears or tools store.
http://www.sears.com/shc/s/p_10153_12605_00904458000P

They are less at harbor Freight, and you don't need the nicest one. I've had mine for 30 years. When you need it it always works with little effort.

http://www.harborfreight.com/catalogsearch/result?category=&q=stud+remover

You can use it to put them in as well. Double nutting is a little barbaric.   :)
« Last Edit: December 09, 2010, 08:29:05 PM by MCRider »
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1988 NT650 HawkGT;  1978 CB400 Hawk;  1975 CB750F -Free Bird; 1968 CB77 Super Hawk -Ticker;  Phaedrus 1972 CB750K2- Build Thread
"Sometimes the light's all shining on me, other times I can barely see, lately it appears to me, what a long, strange trip its been."

Offline wohali

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Re: My first rebuild/restore ever: 78 CB750F3
« Reply #35 on: December 11, 2010, 11:25:45 AM »
At my wit's end here with the studs. I have tried:

  • Cutting the rubber seals off of the 4 heavily corroded studs to better expose the threads
  • Soaking the bottom threads/case in CarQuest penetrating oil, SeaFoam, and WD-40
  • Double nutting with Home Depot/Canadian Tire nuts: the nuts' threads fail
  • Double nutting with the stock cylinder head nuts: Works, but destroys the nuts
  • 2x Vice grips on the studs - perhaps my vice grips are too big but they just spin on the shaft, can't get any decent grip
  • Propane torch on the crankcase where the stud enters for a few minutes, even through the opening for the cylinder, right on the outside of where the threads must be - not helping at all
  • Giving the end of the stud a good whack with a 3" sledgehammer, down into the case, and then a whack sideways, about halfway down, to try and loosen, right after heating - not helping at all
  • The stud remover I got won't grip on a stud with a diameter this small.
  • Bent one of the studs at a 90 degree angle after heating, quenched, slipped the box end of a 15/16" wrench over and torqued - the bent part "corkscrewed" and turned an additional 90 degrees, without rotating the shaft. See pic below:



I haven't tried the oven trick yet because the case is not yet split, I didn't want to invert the case until these were removed because I didn't want to build a jig to hold the engine while inverted without putting weight on the studs. I may have to revisit that decision...but it won't matter, I want these studs out anyway, and I'm unconvinced 10 minutes in a 400 degree oven is going ot be any more or less effective than a localized blowtorch.

Right now I am thinking I'll just go back, use the stock cylinder head nuts, countertorque them, destroy them all, and take up someone's kind offer to send me a new set to use with the APE studs when they arrive next week.

Other ideas welcome.
« Last Edit: December 11, 2010, 11:43:28 AM by wohali »

Offline GammaFlat

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Re: My first rebuild/restore ever: 78 CB750F3
« Reply #36 on: December 11, 2010, 12:37:54 PM »
You should be able to find a stud remover of one kind or another that will do it - read on ;).  Aside from that, a vice grip will hang on if tightened enough.  When you think you can't tighten the grip of the vice grips any more, go another 1/4 turn ;) and then close them with the heals of both hands, elbows pointed outward, as if crushing a beer can.  If that doesn't work, go the nearest bar and find the biggest ugliest dude (stud remover type 2) you can and offer him a six pack for clamping down the vice grips for you.

I also think it's worthwhile to use a 50/50 mix of acetone and ATF as a penetrant. I would not have believed it was better than a lot of stuff off the shelf if I hadn't used it myself.  It is my "rust buster" of choice.      
« Last Edit: December 11, 2010, 12:43:12 PM by GammaFlat »
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Offline SOHC Digger

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Re: My first rebuild/restore ever: 78 CB750F3
« Reply #37 on: December 11, 2010, 12:54:55 PM »
Try the impact driver like I said.  You've tried damn near everything else.

Offline wohali

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Re: My first rebuild/restore ever: 78 CB750F3
« Reply #38 on: December 11, 2010, 05:20:28 PM »
After a lot of weeping, wailing and gnashing of teeth, 13 of the 16 studs are out. 2 of the remaining ones are the badly rusted ones; the third is the back center one on the same side that has an oil feeder hole.

What worked best? ATF+Acetone, a bit of time, and either wrenches & counter-torqued nuts (best) or 2x vice grips (OK, but tended to ruin the stud instead of turn it). In fact, on the remaining three, I've given them more ATF+Acetone to soak in, and will try again in the morning.

SOHC Digger: I don't quite get how an impact driver works in this situation. I also have an air ratchet. If I slip it (or the impact driver) with a 13mm socket over both nuts, they both just spin off at the same time. And to do so I have to get them exactly aligned...which is somewhat difficult. I guess if I had a socket that was keyed shallowly and ONLY turned the one nut it'd make more sense to me. Am I missing something?

Offline GammaFlat

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Re: My first rebuild/restore ever: 78 CB750F3
« Reply #39 on: December 11, 2010, 06:01:10 PM »
If I may answer for Digger.... I have had really good luck with an impact driver in otherwise desperate circumstances.  In your case, you might have needed to get the nuts tightened together more so that they'd stay in one spot.  It's a little dicey 'cause the stud may break where you're stressing it.  On to the impact driver... An impact driver has a unique way of applying pressure.  It hits the nut/bolt/whatever with a very sharp "hammering" rotational force.  When we put a wrench/ratchet/whatever to a bolt, we generally apply pressure very gently working our way up to lots of foot pounds.  The sharp crack(s) of an impact driver may be just what the doctor ordered for releasing the gripping force whether that's stretching threads, corrosion, being bottomed out, etc. 

I have been able to remove the front sprocket nut from my KLR650 with an impact driver as if it were nothing when just moments before, I couldn't make it budge with a breaker bar and 3 foot pipe (extension).  I've also been able to disassemble shocks with an impact driver when other methods failed. 

I'll be removing my studs (probably in a matter of days) on my K6, so I'm watching this thread with a bag of popcorn :) 
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Offline MCRider

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Re: My first rebuild/restore ever: 78 CB750F3
« Reply #40 on: December 11, 2010, 06:12:16 PM »
"•The stud remover I got won't grip on a stud with a diameter this small."

Doesn't that contain its own answer? Get one that does. That's the proper tool to use.
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Offline wohali

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Re: My first rebuild/restore ever: 78 CB750F3
« Reply #41 on: December 11, 2010, 06:16:11 PM »
GammaFlat: OK, I see now. Your point is the impulse step function of force from the impact driver would outperform a more gradually applied force. Indeed, on those studs I did by hand, I often got better results by "running at" the wrench or vice grip, a sudden tug/push vs. a slow steady one. On one of them, I only got it loose by whacking the end of the vice grip with the sledgehammer. Same principle!

MCRider: It's a bit late. Unfortunately, on 2 of the remaining three, neither a stud remover not an impact driver will help. For the one, I've already bent it into an L shape (see above pic). For the second, just straightforward torquing has started to bend it in an alarming way about 1.5" up from the crankcase, so I'm planning on vice gripping that one at or below that point instead. I might give a driver/remover a go on the 3rd one, though.

I've decided that tomorrow I'll get a smaller vice grip pliers, one where the curvature of the jaw will more closely match the small stud (and not tend to just rotate), and a new stud remover. It'll give me a chance to get another propane cylinder to heat the block as well, and have the Sunday morning donuts and coffee, too :)
« Last Edit: December 11, 2010, 06:25:41 PM by wohali »

Offline MCRider

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Re: My first rebuild/restore ever: 78 CB750F3
« Reply #42 on: December 11, 2010, 06:20:29 PM »
I hate where this is going but you may end up with a broken stud. I had one and had to take it to a machinist. They welded an extension on to it, and heated the case up cherry hot to get it out. Some of them are just b--stards as you are finding out. Sorry. (has heat been in your list of things to use yet?)
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Offline wohali

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Re: My first rebuild/restore ever: 78 CB750F3
« Reply #43 on: December 11, 2010, 06:26:40 PM »
Yeah, I tried heat multiple times. The last try emptied the last of the propane in the cylinder. I'm eyeing the oxy-acy setup in the corner and wondering if perhaps that might be too hot for the aluminum alloy the crankcase is made out of... what do you think? It's no big deal for me to just get more propane at Crappy Tire tomorrow.
« Last Edit: December 11, 2010, 06:32:57 PM by wohali »

Offline wohali

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Re: My first rebuild/restore ever: 78 CB750F3
« Reply #44 on: December 11, 2010, 06:30:43 PM »
In another forum discussing stud removal in automobile engines, they suggested this:

http://buy1.snapon.com/catalog/item.asp?P65=&tool=all&item_ID=10349&group_ID=1247&store=snapon-store&dir=catalog

No way I'm going to spend that much...but I sure bet it'd work!

Offline SOHC Digger

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Re: My first rebuild/restore ever: 78 CB750F3
« Reply #45 on: December 11, 2010, 06:37:38 PM »
In another forum discussing stud removal in automobile engines, they suggested this:

http://buy1.snapon.com/catalog/item.asp?P65=&tool=all&item_ID=10349&group_ID=1247&store=snapon-store&dir=catalog

No way I'm going to spend that much...but I sure bet it'd work!

By the time you buy that, a machine shop could get your studs out and save you the money.  GammaFlat is correct about the impact driver.  When you use a wrench or vise-grip, especially on long studs like these, most of your torque is lost by the flexing of the stud.  The stud absorbs the turning motion.  The shock that the driver delivers is transferred to the threads and has a great effect.  Good luck!

Offline GaJet

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Re: My first rebuild/restore ever: 78 CB750F3
« Reply #46 on: December 11, 2010, 06:50:17 PM »
Heat the stud it self at the base where it goes into the block utill it is red, then quench the stud with light oil like WD 40. You may have to do this several times. I have got some really stubborn studs out this way. The important thing is to quench the stud when it is red hot. I believe this breaks the rust bond. Try it, it has worked for me.
GaJet

Offline scottly

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Re: My first rebuild/restore ever: 78 CB750F3
« Reply #47 on: December 11, 2010, 07:05:22 PM »
Do you have a MIG/ wire-feed type welder? Slip a nut over the end of the stud and fill in the center with weld. (I would try this first on the stud you already bent: cut it off an inch or so above the crankcase, slip the nut on, and weld. Then, as the stud is cooling, touch a candle to the joint where the stud enters the case.) Good luck!
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Offline wohali

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Re: My first rebuild/restore ever: 78 CB750F3
« Reply #48 on: December 11, 2010, 07:07:42 PM »
Nah, just propane and oxy/acy nozzles, and 240V -> AC/DC stick. No MIG/TIG or wire-fed....

Offline scottly

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Re: My first rebuild/restore ever: 78 CB750F3
« Reply #49 on: December 11, 2010, 07:25:44 PM »
You could do the same thing with a stick welder, with small rod, say, about 1/16". Keep the electrode focused in the center of the stud, and allow the pool to flow outward into the nut.
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