Insanely Stuck Swingarm Bolt

Im already spending a ton on a full motor rebuild so the added price of getting new bearings pressed in/new pivot axle isn't that big of a deal. Just need the existing bolt out of the frame and gone

In my early years in the Navy they used Wintergreen to free stuck bolts. Another method is 50/50 ATF and Acetone, much better then WD-40. The biggest problem you will have is getting whatever you use past the seals and into the bearing sleeves. All I can say is patience and persistence.

Pb blaster will get you much further than wd40 with a stuck bolt, soak it let it sit soak it again then heat the piss out of it and it should come out, even if gotta beat hell out of it to get it out, you’ll just have to get new bolt probably.

https://www.amazon.com/dp/B0018AIJR2/ref=sspa_dk_detail_4?psc=1&pd_rd_i=B0018AIJR2&pd_rd_w=On3rj&pf_rd_p=21517efd-b385-405b-a405-9a37af61b5b4&pd_rd_wg=YZ5WM&pf_rd_r=WHCSJHRH1DEZRQQM3HFE&pd_rd_r=8339fea3-09b4-11e9-8165-45849ee12971

Did you check to make sure the corners on the head of that bolt didnt dig into the frame? I had that issue on a yz250 i build. Had to rotate the head inside the hole with a flat head to get it out.

Lay the bike on its side and soak in auto tranny fluid/acetone, 50/50 mixture. Let soak for several hours. Flip the bike over to the other side and soak. Heat the area and commence pounding.
Good luck.

Kroil is the best penetrating lube I have found. Pulling everything possible off frame and puttin in press would be best bet, imo. Using a torch to heat bearings is tough as the are relatively protected but probably would hurt......

Air hammer some call it an air chisel. It will hammer it out no problem.

Thanks for the help guys. Gonna try getting some kroil and commence spraying on and off for about a day and try pounding it. Worst case scenario I have a buddy that works at MetzFab and ill either get it pushed out on their hydraulic press or milled out (highly doubt I'll need that). Eventually going to post a clean up thread about the entire bike

I've had good experience with bolt off from nutec, I feel it work better than wd, pb blaster or jb 80,

https://www.amazon.com/Nutek-Bolt-Off-Lubricant-BET-0002/dp/B002TNX3GY#

I rebuilt an 09 yz 250 with same issue. Soaked it in pb blaster and I rigged up a bearing puller type deal with a socket, some threaded rod, washers and nuts. I tightened the puller so the bolt was under tension and then pounded on it with a hammer at the same time. Worked better than just pounding on the thing and it finally broke free. Made a horrendous noise once it broke free. Best of luck.

Maybe already mentioned.........and I had to do this , and it saved me a huge pain in the ass! sawzall it with a fine metal blade , yard the motor out , and then get that thing pressed ( ever so gently ) out of the motor. Once those pivot bearing wear a grove on the pivot bolt , you are literally trying to slide it , with multiple little bearings holding it in place. Cut the SOB , press out the old one , and then order up a new pivot bolt , seals and bearing.....and be done with it!

jeffro503 wrote:

Maybe already mentioned.........and I had to do this , and it saved me a huge pain in the ass! sawzall it with a fine metal blade , yard the motor out , and then get that thing pressed ( ever so gently ) out of the motor. Once those pivot bearing wear a grove on the pivot bolt , you are literally trying to slide it , with multiple little bearings holding it in place. Cut the SOB , press out the old one , and then order up a new pivot bolt , seals and bearing.....and be done with it!

Well, couldn't get the axle loose so we said screw it and took an angle grinder to it. The steel sleeves on the cases, the swingarm itself and the aluminum frame were not touched and are okay. Started with a 4 ½ wheel on a ⅞" arbor grinder and would move up to a 5" and 7" wheel to make it work, everything came out fine besides the leftover remains of the axle on the right swingarm bearing. Ended up heating the shit out of it and knocked it out. Dropping the motor off tomorrow/monday at factory edge and overnighting parts from Rocky Mountain monday, just going to have to wait on the new cylinder and hopefully will have it by the end of this week/start of next week

jeffro503 wrote:

Maybe already mentioned.........and I had to do this , and it saved me a huge pain in the ass! sawzall it with a fine metal blade , yard the motor out , and then get that thing pressed ( ever so gently ) out of the motor. Once those pivot bearing wear a grove on the pivot bolt , you are literally trying to slide it , with multiple little bearings holding it in place. Cut the SOB , press out the old one , and then order up a new pivot bolt , seals and bearing.....and be done with it!

buzzlight52 wrote:

Well, couldn't get the axle loose so we said screw it and took an angle grinder to it. The steel sleeves on the cases, the swingarm itself and the aluminum frame were not touched and are okay. Started with a 4 ½ wheel on a ⅞" arbor grinder and would move up to a 5" and 7" wheel to make it work, everything came out fine besides the leftover remains of the axle on the right swingarm bearing. Ended up heating the shit out of it and knocked it out. Dropping the motor off tomorrow/monday at factory edge and overnighting parts from Rocky Mountain monday, just going to have to wait on the new cylinder and hopefully will have it by the end of this week/start of next week

Good job man. Those dang swingarm bolts and even pivot bolts can be almost impossible to remove once the get a groove and corroded. Sounds like you're making progress.

Just had the same wrestling match yesterday with my son's 07 CR125. An overnight dose of Kroil followed by discreet air-hammering by our local ace vintage moto mechanic did the trick. From now on, we're going to pull the thing every time we grease the linkage bearings.

Some bikes I have were previously owned by Pro-Seize people. I am more on the "Anti-seize" side myself... nickel, copper, whatever, something besides nightmares.

buzzlight52 wrote:

Thanks for the help guys. Gonna try getting some kroil and commence spraying on and off for about a day and try pounding it. Worst case scenario I have a buddy that works at MetzFab and ill either get it pushed out on their hydraulic press or milled out (highly doubt I'll need that). Eventually going to post a clean up thread about the entire bike

"Gonna try getting some kroil and commence spraying on and off for about a day..."

In your particular case this is likely pointless if it is stuck because of rust, because it can, and often does, take several days to a week or more for the kroil oil to penetrate deep enough, plus it works best with gravity, meaning that the bike should be placed on its side then the oil should be put on the top of the offending area.

It sometimes helps to make a "Dam" that will somewhat retain the oil so it doesn't simply run right off the area you need it on. You can try good quality masking tape or duct tape and wrap it around the pivot bolt boss in the frame if there is one.

Also contrary to the "test" that was done comparing 50/50 trans fluid and acetone, it is a superficial test and therefore does prove that it penetrates better then kroil oil, however, mixing a small percentage of acetone with kroil oil might improve its penetrating qualities and you could even call them and ask them what they think about adding acetone to their oil, however, their answer might not be completely accurate since they are biased towards their product and probably think it works best just as it comes out of the can.

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This guy tests several different penetrating oils...

KDXGarage wrote:

Some bikes I have were previously owned by Pro-Seize people. I am more on the "Anti-seize" side myself... nickel, copper, whatever, something besides nightmares.

Yeah, our 125's first owner was definitely a Pro-Seizer. We have had to replace several motor mount bolts. We rescued this bike just in the nick of time. The previous owner's response to the grossly rich jetting these bikes came with from Honda was to go richer on the main jet and run a super hot spark plug from a lawn mower. Luckily, we took it away before he holed the piston (or worse).

Matt Fisher wrote:

This guy tests several different penetrating oils...

Again, unfortunately not a scientific test where the amount of rust on each bolt is documented to be the same amount etc, which is the problem with these home made tests that can lead to inaccurate results. Also, for the results of any test to be valid, the results must be the same every time the test is done. Since the amount of torque it took to remove the 4 nuts for each sample varied by as much as around a whopping 25 ft lbs within each sample alone, and amount of torque it took to remove some of the nuts is within 2 lbs after the numbers of each sample were added together, it obviously can't be said definitively exactly which one was better than the other.

Here's another "comparison" that lists liquid kroil oil as the best and liquid wrench in 7th place.

https://autosneed.com/best-penetrating-oil/

Matt Fisher wrote:

This guy tests several different penetrating oils...

barnett468 wrote:

Again, unfortunately not a scientific test where the amount of rust on each bolt is documented to be the same amount etc, which is the problem with these home made tests that can lead to inaccurate results. Also, for the results of any test to be valid, the results must be the same every time the test is done. Since the amount of torque it took to remove the 4 nuts for each sample varied by as much as around a whopping 25 ft lbs within each sample alone, and amount of torque it took to remove some of the nuts is within 2 lbs after the numbers of each sample were added together, it obviously can't be said definitively exactly which one was better than the other.

Here's another "comparison" that lists liquid kroil oil as the best and liquid wrench in 7th place.

https://autosneed.com/best-penetrating-oil/

And another comparison done by Machinist's Workshop Magazine back in 2007.

"The April/May 2007 edition of Machinist's Workshop did a test of penetrating oils where they measured the force required to loosen rusty test devices. Buy the issue if you want to see how they did the test. The results reported were interesting. The lower the number of pounds the better. Mighty interesting results for simple acetone and tranny fluid!

Penetrating oil . Average load .. Price per fluid ounce
None ................. 516 pounds .
WD-40 .............. 238 pounds .. $0.25
PB Blaster ......... 214 pounds .. $0.35
Liquid Wrench ... 127 pounds .. $0.21
Kano Kroil ........ 106 pounds .. $0.75
ATF-Acetone mix.. 53 pounds .. $0.10

The ATF-Acetone mix was a 50/50 mix (1 to 1 ratio)."


We all see how bike tests go each year, so believe what you want to believe and use what you feel works for you.

Matt Fisher wrote:

This guy tests several different penetrating oils...

barnett468 wrote:

Again, unfortunately not a scientific test where the amount of rust on each bolt is documented to be the same amount etc, which is the problem with these home made tests that can lead to inaccurate results. Also, for the results of any test to be valid, the results must be the same every time the test is done. Since the amount of torque it took to remove the 4 nuts for each sample varied by as much as around a whopping 25 ft lbs within each sample alone, and amount of torque it took to remove some of the nuts is within 2 lbs after the numbers of each sample were added together, it obviously can't be said definitively exactly which one was better than the other.

Here's another "comparison" that lists liquid kroil oil as the best and liquid wrench in 7th place.

https://autosneed.com/best-penetrating-oil/

dkurtd wrote:

And another comparison done by Machinist's Workshop Magazine back in 2007.

"The April/May 2007 edition of Machinist's Workshop did a test of penetrating oils where they measured the force required to loosen rusty test devices. Buy the issue if you want to see how they did the test. The results reported were interesting. The lower the number of pounds the better. Mighty interesting results for simple acetone and tranny fluid!

Penetrating oil . Average load .. Price per fluid ounce
None ................. 516 pounds .
WD-40 .............. 238 pounds .. $0.25
PB Blaster ......... 214 pounds .. $0.35
Liquid Wrench ... 127 pounds .. $0.21
Kano Kroil ........ 106 pounds .. $0.75
ATF-Acetone mix.. 53 pounds .. $0.10

The ATF-Acetone mix was a 50/50 mix (1 to 1 ratio)."


We all see how bike tests go each year, so believe what you want to believe and use what you feel works for you.

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I was aware of that one around 20 years ago, and that is also not a very unscientific test and it has been debunked by....machinists on a machinists forum, lol.


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Really, did you read the Magazine? The same could be said for the autosneed .com page. Also, I believe you meant to say a very scientific test.

Like I said, not going to argue about penetrating oil, use what you think works for you.