Topic: CB750: Head Stud Removal

[Loudpipe]

Anybody got any tips on how to get these out?  I read that they are loctited in, but I don't know if that's true or not.  Double nut trick sure doesn't work.

[Jerry Rxman Griffin aka MuthaF'er]

Any combination of double nuts, vise grips, and/or stud remover with a dose of heat thrown in and soaking with penetrant. 

[eurban]

Search this subject.  It comes up often . . .

[Loudpipe]

I did, and nothing came up.

[bunghole]

I used the bend and turn method.  Bend em down and turn them.  You'll have to replace them, but I assume you are since you are removing them.  There is some risk of them shearing off when doing this, but I didn't have any problems...other than sore hands.

[scondon]

I used the bend and turn method.  Bend em down and turn them.  You'll have to replace them, but I assume you are since you are removing them.  There is some risk of them shearing off when doing this, but I didn't have any problems...other than sore hands.

   I've adopted this method too. Seems they are less likely to shear this way than double nutting, or maybe it's the pounding with the hammer to bend them down that helps loosen them up. About a 35-40 degree bend seems good.

[SD750F]

My machinist taught me to use heat and sweet Gulf Wax (used in canning) down the bolts before trying to twist them out. Worked great on all but the inside front four of my studs. Wonder why? Added heat? Mechanical location with additional or lack of surrounding aluminum? But after I started to "twist" the standard studs I decided to have the same machinist try. Will let you know how it comes out.

Scott

[Loudpipe]

Is there such a thing as a stud remover?  There has to be.... While bending/heating/double nutting, and other methods may work just great, that can't be the proper way to remove a stud.

Wish I had a torch.  Maybe I'll get one of those small propane ones.  Should work.

[754]

Are you removing them to go to 1/4 inch?

I have a stud remover that goes beside the stud and a knurled element cams over and locks to the stud, will try to check if it grabs these.

[Jerry Rxman Griffin aka MuthaF'er]

Stud remover, yes. I got mine at Sears I believe. Harbor Frieght wasn't as close. It works with your socket wrench. Wish I could post a picture. It has a "wheel" inside that grabs/snugs up against the stud so you can use the wrench to turn it.

[Big Jay]

The best stud remover is from Snap On. Use it with a long extension on the ratchet and grab the stud as low as possible.

We prefer to smack the top of each one with a hammer as this helps shock the threads in the case and helps loosen them. We have never found it necessary to use heat.

About those new replacemants...   http://cbrzone.com/studs.html

[KB02]

Are you removing them to go to 1/4 inch?

I have a stud remover that goes beside the stud and a knurled element cams over and locks to the stud, will try to check if it grabs these.

I've got one of these, too. Not sure yet how well it will work. I'll let you know in about two weeks. My new studs (Thanks, APE) will be here early next week and the week after I'll be able to start working on my engine again.

[SD750F]

I have used the remover KB02 had a picture of... And it works okay, but was made for 10mm or larger studs. The smaller of the two stud location holes will not grab the reduced shaft of the standard 8mm studs properly with enough grab to work quite right. So I had to grab the top threads of my standard studs. And this is only good if you know you are going to replace all of them like I did...

Scott

[eurban]

While there are stud removal tools, if you are doing this only once then you can get by with other techniques.  I double nut the top of the stud and use vice grips down low.  Use penetrating oil and then heat things up around the stud base. Have a friend turn either the top or the bottom while you turn the other.  Some bend over the studs and then turn them by hand.  Oh, and from the Tech Forums menu I searched for "stud removal" and had quite a few hits with useful info.  Discussions RE Heavy Duty studs inevitably discuss how to get the old one out.  There have also been a number of discussions on what to do if you break a stud off. . . . 

[scondon]

Are you removing them to go to 1/4 inch?

I have a stud remover that goes beside the stud and a knurled element cams over and locks to the stud, will try to check if it grabs these.

I've got one of these, too. Not sure yet how well it will work. I'll let you know in about two weeks. My new studs (Thanks, APE) will be here early next week and the week after I'll be able to start working on my engine again.

   Those things are good for typical removal. They will burr the shaft of the stud if it's stuck tight though. Do not grip them on the stud TOO close to the bottom end gasket surface as the large gear at the bottom will chew into aluminum like a hot knife through butter. Hold it level while you turn the wrench to make sure force is applied properly for removal, if it "cocks" on the shaft then you're more likely to snap a stubborn stud. If the stud does snap it is stuck in this tool and can be a real #$%* to remove from the tool.

   After snapping several studs with this tool I pitched it to the bottom of the tool box. I'll use it, just not on stubborn studs.

EDIT: Snapped studs were from the 4 "dry" holes in a F2 engine, rusted and in pretty frickin' tight. Not saying this tool is prone to snapping studs.

[RRRToolSolutions]

Jay, Sean, I respect your comments and experience, but I personally have not had good luch without heat.

My old friend and long-time machinist Charles (maker of frame kits Charles) has worked on aluminum heads everyday for over 30 years and has never broken a stud. Me, I've done 6 motorcycle engines where I removed every stud and I've broken 2 off. The corrosion of 2 dis-similar metals and the fact the threads are different - somehow a more precise fit and you have recipe for broken studs. (I've screwed up a nice H2 case and original studs by using a regular tap and die to chase the stud and case threads - they had slop in them afterwards).

I wanted your APE studs installed in my CB750 hotrod project bike. Charles heated the block in an oven to 400 for about 10-15 minutes and removal was super easy. He used 2 Visegrips clamped near the bottom in opposing positions (12 and 6 o'clock) and turned then a half turn. The opposing force keeps side-load from adding to the stress the stud has during removal. I then took a socket and simply turned them the rest of the way using a ratchet and double nuts. The initial break was what made it safe.

According to him, you can use a torch or the oven - what you want to do is heat the aluminum block and not the studs. The studs don't heat up as fast since they are a lot more dense. Nowadays, I will try to get them out since it makes cleaning the gasket surface easier and I like to have them hard-chromed. In the case of my KZ900 project just done, I wanted to install APE studs, but if double nutting won't do it - then I leave them alone. If I had the cases apart, then in the oven they would go. Here is a complete set of "chromed" 1970 H1 studs - but heat was mandatory.

When they break - it's not pretty and not something an Easy-out tool is going to handle.

Regards,
Gordon

[scondon]

Jay, Sean, I respect your comments and experience, but I personally have not had good luch without heat.

My old friend and long-time machinist Charles (maker of frame kits Charles) has worked on aluminum heads everyday for over 30 years and has never broken a stud. Me, I've done 6 motorcycle engines where I removed every stud and I've broken 2 off. The corrosion of 2 dis-similar metals and the fact the threads are different - somehow a more precise fit and you have recipe for broken studs. (I've screwed up a nice H2 case and original studs by using a regular tap and die to chase the stud and case threads - they had slop in them afterwards).

I wanted your APE studs installed in my CB750 hotrod project bike. Charles heated the block in an oven to 400 for about 10-15 minutes and removal was super easy. He used 2 Visegrips clamped near the bottom in opposing positions (12 and 6 o'clock) and turned then a half turn. The opposing force keeps side-load from adding to the stress the stud has during removal. I then took a socket and simply turned them the rest of the way using a ratchet and double nuts. The initial break was what made it safe.

According to him, you can use a torch or the oven - what you want to do is heat the aluminum block and not the studs. The studs don't heat up as fast since they are a lot more dense. Nowadays, I will try to get them out since it makes cleaning the gasket surface easier and I like to have them hard-chromed. In the case of my KZ900 project just done, I wanted to install APE studs, but if double nutting won't do it - then I leave them alone. If I had the cases apart, then in the oven they would go. Here is a complete set of "chromed" 1970 H1 studs - but heat was mandatory.

When they break - it's not pretty and not something an Easy-out tool is going to handle.

Regards,
Gordon

Good info Gordon. I especially like the part about opposing vice grips

  Also like the part about heating the entire case in an oven. Using a hand held butane torch just didn't work for me. The aluminum case is so good at dissipating heat that in the time it took to set down the torch I could press my finger against the area around the stud without even thinking "ouch".

  *My limited experience with stud removal has me breaking it down into these categories:

Studs that can be removed regardless of method- 75%

Studs that need heat, impact, or other TOT's-        20%

Studs that will snap no matter what voodoo you practice- 5%


*Warning: this is just an opinion and is subject to change at manufacturers discretion

[Gamma]

I used your technique Gordon after researching the postings.
Heated the case in the oven, 2 pairs of Mole grips low down opposing each other, (got a mate to hold it down on the bench with oven gloves) and double nut at the top to undo each one after initial movement.  Whilst cleaning the threaded holes in the case, I also hacksawed a vertical slot in one of the removed studs threaded area, to make a thread chaser.  

[754]

You guys are missing 2 major points here

The success of removing studs or bolts depends GREATLY on insuring no aluminum comes out with them.. So the first step after cracking it loose depends on moving it back and forth to make sure this does not happen..

You said you ruined threads by chasing with a tap.. which tap.?? Taps are ground to thread limits and you should use a good one, not whatever is handy.. cheap taps are not even ground threads, and are of poor tolerances..

[ksmith0034]

I just replaced my studs recently.  They were ALL stuck, so I first shot PB Blaster down into the threads and let it sit a day or so (PB Blaster is the greatest stuff since sliced bread-check it out).  Then, after TIGHTLY double nutting, my buddy carefully heated the block, (NOT the studs!!!) as I slowly backed out each stud using the lowest setting on my impact.  They all came out like butter.  Just take your time and don't force anything.  The last thing you want to do is twist one off!  BTW, don't forget to replace them with heavy duty studs like APE.  They are a lot beefier and won't stretch like stock studs.  You don't want any leaks! 

[MRieck]

 I'm with Gordon and Gamma on this one....I use heat. I use a thread chaser....NOT a tap to clean the holes out. There is a difference between the two tools.

[Gamma]

http://i192.photobucket.com/albums/z293/galaxy8155/ElCheapoThreadChaser.jpg[/img]]

[scondon]

http://i192.photobucket.com/albums/z293/galaxy8155/ElCheapoThreadChaser.jpg[/img]]

 Nice Can I borrow it

[bunghole]

I'm kicking myself for throwing my bent ones out!

Where can I find a good set of thread chasers?  I've been looking all over the place and can't seem to find a set.  All I can find are taps which I already have.

[MRieck]

I'm kicking myself for throwing my bent ones out!

Where can I find a good set of thread chasers?  I've been looking all over the place and can't seem to find a set.  All I can find are taps which I already have.

Craftsman, Snap-On or Mac. They all look to be the same item in all honesty (the Snap-On is their Blue Point line). They are an excellent addition to a tool collection.

[bunghole]

This one?:

http://www.sears.com/shc/s/p_10153_12605_00942275000P?vName=Tools&cName=Mechanics+Tools

[MRieck]

This one?:

http://www.sears.com/shc/s/p_10153_12605_00942275000P?vName=Tools&cName=Mechanics+Tools

That's it.

[Gamma]

Mines a lot cheaper.
Anytime Sean.
But I've just managed to add the Snapon version RTD48 to a new work tool kit 

[KB02]

All this talk of stud removal has gotten my interest up. I just spent 45 minutes out in the garage pulling studs. I only pulled the back half as they are all the same length and I won't have to worry about which ones are the shorter ones when my new studs get here.

Turns out this is the stud remover that I have:


It only has the one whole, not two. It is so big that I had to place it right on the threads to get a good purchase . A quick shot of penetrating oil at each base and I was off. The first stud (right side of engine) came right out no problem. No heat applied to any other them. The rest were all about the same. The only problems I had were the studs that are very close to each other (Between 1 & 2 and 3 & 4 - It's a 750, by the way). I could break them loose, but didn't have enough room to spin the big honkin' tool around to keep going with the remover. On one of those, on each side, I had to use the double nut trick. This is where attaching the stud remover to the threaded area became an issue.   

Will the front half take me nearly 45 minutes? Nah... unless I break one... I'm keeping my finger crossed... 

[RRRToolSolutions]

Guys, I'm glad to hear some of you have no problems. I had 6 engines and 30 to 51 studs each (my most recent 1970 H1 had 51 threaded studs). Of those 300 or so studs removed 2, just 2 studs that is - I got to experience that sickening feel of loss of resistance. What I learned then was that double nutting one will normally get it out - if it's going to come. It's only when I added my big-daddy pair of Visegrips to the leverage party did I wring-off those thick 10mm studs on my first Kawasaki H2. The smaller 8mm ones would take much less. My theory is that whatever can be transmitted through the jammed nuts on the threads is ok without heat. Before I apply more than 2 nuts will bear - then I'm going for the oven.

I just tried to remove 12 cylinder studs from my KZ900 so I could add the APE replacements. My attemps had the stud twisting along it's length - no way! I was not going to add the Visegrips - they will stay in there until I restore it fully in 10 years after I've gotten too old too ride it.

I'd like to see a new thread "How to remove broken studs below the surface of the crankcase" - neither of mine were broken above the block so there was nothing to weld to. The machine shop gave me back a block with off-center holes. I wound up giving the block to a friend who needed one for a jig to make expansion chambers.

Good luck with those dice.........

[DoctorMuffn]

I haven't had any luck so far...

Actually that's not entirely true. I've pulled 12 of the 16 studs from my '78 CB750F motor. I ended up using the stud puller referred to by KB02; I used the same technique since I'm replacing the studs with APEs I got from Ken at Cycle Exchange and wasn't worried about marring the threads. The double nut method wasn't working for any of the studs; the nuts started to spin. The vice grips slipped. The puller gave me results for all but 4 studs which snapped in the middle.

These studs happen to be the weathered ones that have the o-rings at their base. Each of them snapped. I tried welding nuts of different sizes to no avail. My friend (a quality welder) came over to do the same and went lower on the stud. He also used different nut orientations - nut upside down to weld on the flange for better penetration. Each and every time the nut snapped (or really it broke off) taking a piece of the stud with it. We're at a loss...

We'll probably try left-handed bits next and drill into them. I've been doing this with the case together hoping not to need to pull it apart since this is the second rebuild (on the same engine) I've done this year. there's nothing wrong with the case or its internals so I'd like to keep from having to reseal it if possible.

Any suggestions?

[Juan1]

Just wanted to add another data point from my recent experience with a '78k.  I tried PB blaster, and then bent the studs and tried to pull them.  All but 5 studs came out using this method, and those 5 were bending rather than turning.  I then tried applying heat with a torch, which resulted in another stud coming out and a snapped stud.  After all of that, I took the block to the machine shop and they removed the rest and probably overcharged me.  After speaking to the machinist later, he said he just added a good amount of heat, and then used a proper stud puller as can be seen in the picture KB02 posted. 

My advice is this:
1. Do not, repeat, do not try to pull any studs until you have a stud puller like KB02 posted, and a torch.  You do not want to bend or snap the stud.
2. Add PB Blaster and let it soak overnight.
3. Heat the aluminum block around the stud, not the stud with said torch.
4. Pull studs with a stud puller like KB02 listed.

[flybox1]

I worked over a month to get all my upper case studs out.  They bent like noodles trying to twist them out Day 1, and I didnt want to shear any off.  Double Nut Method.  Each weekend I added more PB Blaster.  On the 4th weekend, and after a few whacks from a dead blow hammer, they twisted out.

[PeWe]

I had no problems at all to remove the old studs on my K6-76 (98000kms)   I Used 2 head nuts on each stud. torqued them together and removed the stud by twisting the bottom nut. Some studs were seated harder, on those I torqued the stud a little bit more until it move. Hard clap with a hammer on the wrench. It came loose and easy to remove.

Very important to not torque the HD stud too much. The studs is more rigid and cannot withstand too much torque, it will snap.
torque nuts to 20-22 ft. lbs. (stud installed and torqued with 8 ft.lbs)
The torque wrench might not be exact either. + 4% will end up in over 0.8 ft. lbs extra.

Next question is how much oil and which oil when tighten the nuts. Less oil, more friction that will make the torque wrench to reach its torque earlier, less tension applied on the stud. 

Max 20.5 ft lbs will be the number for me when the HD stud will not flex as OEM (that I torqued almost 21 ft lbs without problems). Wait at least 24hours and re-torque by releasing each nut 1/4 turn direct followed by torque again with same torque as earlier according to the torque pattern from center out to the ends of the head.

[Garage_guy_chris]

Here is what i just went through with 2 of my studs, previous to this method i had them double nutted and left them soaking for a week with probably 20 tries with heat and oil.

Mask open cases from welding spatter



Place nut over broken stud



Here is the hole after breaking the nut off and rewelding it about 5 times then finally getting the thing out there is no damage to the cases its just covered in burnt penetrating oil



Here are the two studs as removed