Topic: Stuck bolt got me stuck..

[materializer]

Hi All,

I recently started taking down my CB650Z prior to rebuilding it into a replica of the Paul Smart CB650 (What A Monster..)
All going to plan but I ran into an issue with one of the bolts that mount the engine in the frame and partially keep the small frames in place that the steps are mounted on.
This is a 12mm bolt, approx 25mm/10" long and runs from one side to the other of the bike, and at two spots goes through the rear/bottom part of the engine.

At the right side of the bike there is the nut to this bolt which came off easily and allowed me to remove the frame and steps. So far so good, .. when moving to the left side to do the same I found the bolt head wouldn't come loose.. It was only after going over the maintenance manual I found that it runs all the way through the engine's rear bottom. And I suspect it is there that it somehow corroded/fused together.. When I put a wrench on it, extend the lever a bit with a pipe and gently apply torque the only thing that happens is that the bolt twists.. so I stopped, way chance of snapping that bolt..

One thing I have been considering is hammering it out from the treaded side  (direction to where bolts head is, so to the left) There should be no threading on the bolt other than the 1.5" on the end which is already exposed.. (going by the documentation)

Please see attached image of the part/location.. Is there anybody that has ran into this same issue, and do you have a fix/method to get it to come loose?
(..oh yeah, I figured it is stuck at the spot of the red dot as I can see the bolt flex along its length when applying force.)

Thanx in advance for any useful pointers and tips!

Monk

[DaveBarbier]

When you say it twists, do you mean that the bolt spins or that the bolt is twisting while being held at the end...so like it might snap? Edit: ok I read your picture.

First, yeah you're probably fighting corrosion but also the motor weight. Use a jack under the oil pan with a piece of wood to slightly lift them motor, that'll relieve some pressure.

Also, use a drift and hammer from the threaded side. Put the nut back on so you don't damage the threads. Once you get it broken free it'll be easier.

Use penetrating oil like PB Blaster and let it soak.

[materializer]

Hi Dave,

Yes I definitely can confirm the bolt twists/flexes.(held at one end - the far end, at approx 10" from the nut)  Just if it is stuck, not at the bolts "head end" but at the threaded end. When I force it with an extended wrench I can flex it a few degrees and can actually see it flex/warp looking at it from underneath the engine where I just see it running underneath.. I have been soaking it in WD40 today and will continue to do so for 2-3 more days as is recommended around. My idea is as you suggested to add a couple of nuts to the treaded side and hammer it out. The only thing that is unclear to me is whether its stuck in the aluminum of the engine or in the steel of the frame.. Is there any chance the bolt might have fused in the aluminium? (hammering it out would be causing definite damage right there) or is it much more likely the corrosion bridge is in the steel/steel?

Monk

[Scott S]

 Jack up the engine just a tiny bit to take the stress off the bolt a d try tapping it out.

[irish44395]

+1 I had to tape the bolt back in when I put the motor back in
Pete

[calj737]

The bolt is steel, the cases are aluminum. They won't fuse together. As said, the motor weight is binding it, and there can be some corrosion surrounding the bolt making it a bit tough.

[DaveBarbier]

I'll just add that WD40 sucks as a penetrant. PB Blaster is much better. There are others out there but WD40 is pretty much useless.

[materializer]

+1 I had to tape the bolt back in when I put the motor back in
Pete

Hi Pete,

Being a relative novice in working with the CB: is what you mentioned anything I need to be weary of?

Monk

[cb650]

whats your location?

[DaveBarbier]

+1 I had to tape the bolt back in when I put the motor back in
Pete

Hi Pete,

Being a relative novice in working with the CB: is what you mentioned anything I need to be weary of?

Monk

I think he means tap the bolt. Like to get the bolt to slide back in a little persuasion with a hammer was needed. That's normal. Biggest thing is to lift the motor a bit to relieve pressure.

[cb650]

the spacers that also go on that bolt are steel and could be the problem.

[irish44395]

+1 I had to tape the bolt back in when I put the motor back in
Pete

Hi Pete,

Being a relative novice in working with the CB: is what you mentioned anything I need to be weary of?
Yes thats what I meant . I had the engine hanging and slid the frame on the motor had to jiggle the frame from time to time and once I got a few bolts in I put it on the lift. pretty straight forward. taking the motor out I had laid it down and pulled the frame off the motor.
Pete

Monk

I think he means tap the bolt. Like to get the bolt to slide back in a little persuasion with a hammer was needed. That's normal. Biggest thing is to lift the motor a bit to relieve pressure.

[materializer]

Not sure what to make of this... I removed the right frame piece to expose more of the threaded rod.
I think for some reason my issue worsened, I def can only assume the rod has fused with the aluminum.

I think the attached images speak for themselves as well as what I saw.. stuck in the right rear aluminum part.
As suggested I went and bought a specific high penetrating compound rust dissolver and will see what happens.. but have an eerie feeling about this.
Ohjeah, I took the hint and lifted the engine up to lessen the weight on the bolt. Will see what happens now after i soak with the new wonder juice.

Monk

[materializer]

whats your location?

Hi Im at Helmond Netherlands

Grtz Monk

Verstuurd vanaf mijn HUAWEI GRA-L09 met Tapatalk

[kmb69]

The bolt is steel, the cases are aluminum. They won't fuse together. As said, the motor weight is binding it, and there can be some corrosion surrounding the bolt making it a bit tough.

Cal, I would have thought the same until recently, but..........

There appears to be something in the aluminum alloy used during this time period that will aggressively corrode with the plating on the bolt to the point that they can essentially become ONE. I just experienced this with a 78 Automatic, top rear mounting bolt, and used AeroKroil for weeks to no avail. Literally could not beat the bolt out with a sledge hammer. Was afraid of cracking the cases. Had to mill it out. Fortunately, this engine was already out of the frame when I got it so I could get it in the machine. I told my partner I had never seen such a thing in my lifetime. Guess it's possible the bolt corroded and grew to an interference fit but it seems to be more like a chemical bonding thing.

Low and behold, I just got another one. Again, a 78 Automatic engine I bought off eBay that was delivered last week. The lower, front engine mount bolt, under the mains, is stuck like chuck. Keep applying the AeroKroil but it ain't budging. Has nothing to do with engine weight on the bolt - it's also out of the frame. Probably also gonna require milling. Mind boggling! Like I said, never seen it before.

Pretty sure Monk is correct when he says it appears he will twist the bolt off. Tough part for him is engine is still in the frame. Ouch!

I think he might try laying the bike on it's side, using an impact wrench to vibrate the bolt, not enough torque to twist it off, and keep applying rust/corrosion penetrant/remover till it loosens. Maybe??

[calj737]

If you lay that bike on its side, use a propane torch on the case where it covers the bolt. You can get galvanic corrosion from dissimilar metals, but I can not begin to think of a situation where carbon steel will "fuse" with aluminum. Then again, I surely don't know everything.

I would not doubt that corrosion, debris, and gunk could easily create a VERY stuck bolt though. If heat and persuasion won't unstick it, acid will. Some soaking with The Works toilet bowl cleaner should erode anything hanging to the steel and not effect the aluminum.

Just another thought...

[Stev-o]

If you lay that bike on its side, use a propane torch...

FYI - this advice is coming from a guy who lights his engine on fire to free up a piston!
No BS....

[calj737]

If you lay that bike on its side, use a propane torch...

FYI - this advice is coming from a guy who lights his engine on fire to free up a piston!
No BS....

It was 4 stuck pistons, for the record 

[ekpent]

 I would definitely NOT use the Works toilet bowl cleaner on aluminum, it can cause a very bad reaction. I mistakenly poured some in an aluminum pan once to soak something and the inside of the pan turned into a bubbling cauldron. You can make a bomb by pouring  Works into a plastic pop bottle and add aluminum foil tightly cap and wait for the boom ! 

[materializer]

If you lay that bike on its side, use a propane torch on the case where it covers the bolt. You can get galvanic corrosion from dissimilar metals, but I can not begin to think of a situation where carbon steel will "fuse" with aluminum. Then again, I surely don't know everything.

I would not doubt that corrosion, debris, and gunk could easily create a VERY stuck bolt though. If heat and persuasion won't unstick it, acid will. Some soaking with The Works toilet bowl cleaner should erode anything hanging to the steel and not effect the aluminum.

Just another thought...

Cal, I deeply respect any one with a standing record like you in sharing and posting your wisdom in this forum but I will most definitely not pour acid on anything I own ever again..
I used to be into 100 Yards long range PCP airgun shooting and one day decided to undo my competition gun of its stock black anodisation. It was recommended to me to soak the parts in various acids for a short while. Did my research and went by the most backed approach through the forum I was with.. The result was a ruined 3K € Piece of cratered misery..
I'll stick to corrosion penetrating oils, unstress the bolt, vibrate with an air powered wrench and see what happens given enough time. I cant afford to lose the engine, will most likely not anytime soon get the money together for a donor as I'm on a poormans budget having three little critters around begging for pocket money

If this bolt is not going to give into my persuation I will probably have to cut it out with an angle grinder and mill it out, as I am "very very weary" of taking the step and putting a propane burner to the carter where the bolt has become stuck (because of galvanic corrosion).  ( @KMB69, Im thinking along these lines aswel now.) 

@ everybody;  thanx so much for your input up till now, it has been of great help to form a picture of what I'm dealing with and what to possibly do.

Regards Monk

[calj737]

Fair enough to be alerted to the acid hazards, but I can guarantee you, there is no means for steel and aluminum to fuse metallurgically. In fact, the aluminum won't corrode when steel contacts it; it's the other way around. So I'm sure its just buggered badly and gummed up. They can be a major source of frustration.

By the way, heat is a perfectly good approach if you can safely maneuver the torch to hit the bolt end and/or case bosses. Absolutely no danger to either component because propane can not get the aluminum hot enough to hurt it (oxidation melts at 3,600*) and the steel at ~2,700*. Heat also helps wick penetrating oil into the crevices.

If your steel spacer is still lodged between the frame and cases, this well might be the major source of your issues. Th bolt and spacer certainly can be stuck like no tomorrow from corrosion. It may be necessary to cut the spacer in half, then drive the bolt out with a drift. If you do have to, let me know, I'll dig up or turn you a new lower engine hangar bolt from 303/304 stainless. No more corrosion 

[DaveBarbier]

It may be very lucky for you that the bolt is stuck by that engine spacer. That's a perfect sacrificial piece that will really help get the bolt out if you cut that in half.

I would be using penetrant and propane and a sledge working the bolt back and forth.

[John Eberly]

The bolt is steel, the cases are aluminum. They won't fuse together. As said, the motor weight is binding it, and there can be some corrosion surrounding the bolt making it a bit tough.

Nonsense, steel and aluminum will certainly fuse from dissimilar metal corrosion. You've never had a bleeder screw stuck in a brake caliper?

I would recommend SOME heat and Aerokroil penetrating oil. Treat it three or four times and then try double nutting and driving the bolt out.

[DaveBarbier]

The bolt is steel, the cases are aluminum. They won't fuse together. As said, the motor weight is binding it, and there can be some corrosion surrounding the bolt making it a bit tough.

Nonsense, steel and aluminum will certainly fuse from dissimilar metal corrosion. You've never had a bleeder screw stuck in a brake caliper?

I would recommend SOME heat and Aerokroil penetrating oil. Treat it three or four times and then try double nutting and driving the bolt out.

This is a symantics argument. What I think Cal is saying is that the two metals (steel and aluminum) will not fuse and become one with each other completely preventing the bolt from being removed. The OP asked if there was a possibility that the two metals fused together.

No one is saying corrosion isn't a bastard and makes all sorts of things get stuck. We all use antiseize on spark plugs to avoid this very thing.

I would recommend more than some heat. Hit that thing with propane, penetrant and a hammer to shock it. You're not going to damage anything. The motor will act like a giant heat sink.

If heat and penetrant doesn't work I would weld a big nut on the threaded end and crank on it from that side. Once it breaks free just cut the bolt head off and slide it out.

[kmb69]

.....
I cant afford to lose the engine, will most likely not anytime soon get the money together for a donor as I'm on a poormans budget having three little critters around begging for pocket money
.....

You are a very rich man!