Wildguzzi.com
General Category => General Discussion => Topic started by: nwguy on June 08, 2025, 12:13:02 PM
-
How would you fix this? It's the lower shock bolt stuck into the pin (part #U03555200) that screws into the transmission. There's no head on the bolt. I ground it off to remove the shock after breaking 3 tools trying to unscrew it. This after a week of soaking the bolt in Kroil, then applying heat, tapping with a hammer, then wrenching. Now realizing I shouldn't have ground the head off yet. I couldn't get heat from my torch onto the pin very well when the shock was mounted. Maybe now that it's exposed heating it would work better.
I could take it to a guy near me who once removed a broken exhaust stud by welding a bolt onto what was left of it. I've never had an Easy-Out work. What would you do?
I do have an email into MG Cycle asking if they have the pin.
(https://i.ibb.co/j9CBsqdr/trans-Pin1.jpg) (https://ibb.co/j9CBsqdr)
(https://i.ibb.co/rKgqp251/trans-Pin2.jpg) (https://ibb.co/rKgqp251)
-
Start with an overnight spray of penetrating fluid; PlusGas, XCP or ACF50/WD40 at a push.
With a tap & die set at the ready, or just a suitably sized tap, use reverse (left-hand) drill bits, moving up sizes until matching the original size. The generated heat and weakening of the bolt threads may well free if off, before a tap of the thread is required.
-
Start with an overnight spray of penetrating fluid; PlusGas, XCP or ACF50/WD40 at a push.
With a tap & die set at the ready, or just a suitably sized tap, use reverse (left-hand) drill bits, moving up sizes until matching the original size. The generated heat and weakening of the bolt threads may well free if off, before a tap of the thread is required.
The OP has already soaked the bolt in Kroil for a week, not sure soaking for another day or with other product is going to do anything.
I'd suggest removing part #34 from the FD housing and simply getting a replacment. If a replacment is unobtanium I'd still remove part #34 from the FD housing and then it can be held square in a vise and drilled and retapped.
-
Someone handy with a simple lathe would reconstruct the entire part. I've done it. But surely there would be plenty of those parts laying around in breaker yards.
Patrick Hayes
Fremont CA
-
I have one of those #34s laying around that I'll never use. Yours for the cost of postage.
-
The OP has already soaked the bolt in Kroil for a week, not sure soaking for another day or with other product is going to do anything.
By the way it was described that was before grinding off the head. :rolleyes:
Not everyone has access to a bench vice and/or vertical drill press.
Of course,replacing it is the easy option.
-
It seems that #34 is threaded on. Why not just unbolt it, and either work on it removed, or just replace it?
-
Agreed. Remove the part and work on it off the bike. Much easier and, stood on end in either a bench vise or a pair vice grips, penetrating fluid will work far more efficiently with gravity rather than against.
Another tip, smack the seized bolt remnant sharply with a hammer….it may simply unwind afterward. Also, with it removed it can be taken anyplace where a welder is present and have a nut welded on for removal.
-
By the way it was described that was before grinding off the head. :rolleyes:
Not everyone has access to a bench vice and/or vertical drill press.
Of course,replacing it is the easy option.
.
Of course one without a bench vice probably shouldn't be attempting it in the first place.
And that person could easily remove it and bring it to a machine shop that won't only have a bench vice but will also have a drill press and a lathe and maybe a CNC machine and and and and... Could do the job.
-
I’ve had success extracting sheared bolts—both the upper rear shock mount—by drilling out the material with a left-handed drill bit and stepping up the sizes until the final sliver was weak enough to come out with the bit.
-
..by drilling out the material with a left-handed drill bit and stepping up the sizes until the final sliver was weak enough to come out with the bit.
See fellas, I ain't the only one! :boxing:
-
To the OP I would also suggest a tourch to heat the area where the bolt is broken off. There is a higher than likley chance someone used thread lock compound on the threads.
-
Charlie I might take you up on your offer for that pin.
I tried unscrewing it from the transmission housing. It turned but didn't seem to unscrew. It might not be threaded into the housing, but instead have a nut inside the housing securing it. Charlie, could you look at the pin you have to see if it's threaded for screwing into the housing vs. taking a nut on the backside? I probably turned it less than one full turn and didn't see any gap form at it's base. Maybe I just need to turn it more. Wondering now if fluid will leak out of there if I don't remove the pin and reinstall it properly. It's above the gear fluid level line but...
I'd rather not dismantle the transmission to remove that pin if it does have a nut on the back side. Would need gaskets to reassemble it, and who knows what other things might happen.
I have a vertical drill press but no welding equipment anymore. If I lay the transmission on my drill press' table, it lays flat and the shaft looks vertical. So it might be OK to use a drill press on the pin without removing it from the transmission housing. I'm not finding left hand drill bits locally in stock, but I know they're online. I have a metric set of taps/dies, but I don't seem to have the tap that matches the shock bolt.
I can't believe Guzzi used a bolt with a 4mm allen head to secure a shock. I cringe now every time I see allen head bolts I need to remove.
(https://i.ibb.co/tMPCrdWf/Transmission.jpg) (https://ibb.co/tMPCrdWf)
-
Charlie I might take you up on your offer for that pin.
I tried unscrewing it from the transmission housing. It turned but didn't seem to unscrew. It might not be threaded into the housing, but instead have a nut inside the housing securing it. Charlie, could you look at the pin you have to see if it's threaded for screwing into the housing vs. taking a nut on the backside? I probably turned it less than one full turn and didn't see any gap form at it's base. Maybe I just need to turn it more. Wondering now if fluid will leak out of there if I don't remove the pin and reinstall it properly. It's above the gear fluid level line but...
I'd rather not dismantle the transmission to remove that pin if it does have a nut on the back side. Would need gaskets to reassemble it, and who knows what other things might happen.
I can't believe Guzzi used a bolt with a 4mm allen head to secure a shock. I cringe now every time I see allen head bolts I need to remove.
It is threaded into the housing, no nut on the inside. No oil will leak out, it's a blind hole.
I loathe those (soft) button head cap screws - had several stuck on the 2000 Jackal roller I just bought. Not much better are the low-head socket head cap screws on my V65SP.
-
I've had luck at times to first smack the end with a hammer, then slightly tighten the bolt then try loosening. It breaks up any mechanical/oxidized bonding in the threads.
-AJ
-
The VERY BEST penetrating fluid is equal parts POWER STEERING FLUID and ACETONE.
Heat up the aluminum surrounding the fitting and bathe in penetrant. Rock the fitting back and forth, tighten, loosen.
Since it's aluminum, you don't want to bugger up the threads.
Me, I'd take Charlie up on his offer, and while waiting for it to arrive, I'd remove the old one and see if I could repair it. I like real-life puzzles.
-
I had the same issue with the rotor bolts on my rear rotor. Seems they are made from some sort of metal colored formaggio. I got one out without having to resort to other measures. I was able to remove 4 using a larger Torx but hammered into the rounded hex socket.
The last one I had to drill the head out until it separated from the shank. With the rotor removed, I smacked the remnant with a big hammer and twisted it out with some Vice-grips. Even my induction heater didn’t work on them….and it got the ones I tried it on glowing red
-
I have a few pairs of Vice Grips, different sizes and jaw types. I only use them when some type of destruction arises.
kk
-
It is threaded into the housing, no nut on the inside. No oil will leak out, it's a blind hole.
I loathe those (soft) button head cap screws - had several stuck on the 2000 Jackal roller I just bought. Not much better are the low-head socket head cap screws on my V65SP.
Thank you Charlie. I don't think I need to remove it at this point. Though I should attempted to tighten it back in the housing. I pondered the left hand drill bits, the metric taps, the easy out, etc. Then, I walked up the street with my final drive to my local mechanic (his name is Tony), and asked him if he could get the bolt out. My local brew pub is half way between my mechanic's up the street and my house. Late this afternoon Tony came walking down the street with my final drive to the brew pub where I was having a nice IPA and handed me the final drive with the now-hollowed out bolt that threaded easily out. I insisted he take $20 but he said no, and said that I should help him fix his bicycle he commutes on. I, a former bicycle mechanic, readily agreed. So problem solved.
Thank you everyone for your thoughts on this! Without Tony, a solution would have happened. But sometimes life gives you lemons.
(https://i.ibb.co/YF86kyM5/trans-Pin3.jpg) (https://ibb.co/YF86kyM5)
Now I have to pick rear shocks. I'm interested in these:
https://steadfastcycles.com/products/hagon-road-shocks-black-slimline-chrome-spring-ajs-650-model-31-1962-63-64
Any thoughts anyone? I've read all about Ikon, YSS, JBS, Racetech, Progressive and cheapo Chinese shocks.
-
Didn't you ask how he done it? :boozing:
Good value shocks are Hagon. :thumb:
-
See what Shock Factory has. Much better than Hagon.
-
See what Shock Factory has. Much better than Hagon.
More expensive compared to basic Hagon and similar price for similar spec. i.e. preload+damping. (UK prices)
-
True, but I've had both, and they are worth the extra money.
-
Didn't you ask how he done it? :boozing:
Good value shocks are Hagon. :thumb:
I talked to Tony this morning. He used regular, not left hand, drill bits to drill out the center of the bolt. Then he used a splined extractor that was not tapered. He said by not being tapered when he hammered the extractor into the bolt, it didn't press the bolt surfaces outwards. So it was easy to unscrew the bolt. He didn't mention using heat.
-
I have Hagons on my Jackal. Made for my specs. The work well enough.
The Shock factory guys know what they are talking about. I'd try them if I was you and was planning on keeping the bike.
Buy one time and cry one time.
I tried some supposedly good cheap ones when I first bought the bike. IKON was the brand. Good value they said. Used to be KONI or some such story.
Compression and damping with one adjustment! They SUCKED. I knew in 5 miles I wasted 300 bucks. Point is I spent twice. My error. Buy quality the first time. It's cheaper.
-
I can't believe Guzzi used a bolt with a 4mm allen head to secure a shock. I cringe now every time I see allen head bolts I need to remove.
(https://i.ibb.co/tMPCrdWf/Transmission.jpg) (https://ibb.co/tMPCrdWf)
The bolt itself doesn't carry any real load. The special threaded pin that screws into the drive box carries the load. The little Allen-head screw and a washer merely keep the shock from sliding off of the pin. There aren't any active forces pushing it off. The problem is exposure to moisture and corrosive thread locking of the metals. I agree, the screw heads are not very robust. If you round out another Allen head bolt/screw try using a Dremel to cut a nice slot and then a hammer impact wrench to get the bolt out. The hand impact wrench imparts torque and shock impact simultaneously.
Patrick Hayes
Fremont CA
-
I talked to Tony this morning. He used regular, not left hand, drill bits to drill out the center of the bolt. Then he used a splined extractor that was not tapered. He said by not being tapered when he hammered the extractor into the bolt, it didn't press the bolt surfaces outwards. So it was easy to unscrew the bolt. He didn't mention using heat.
In this application the OP could install a threaded stud in the pin then use a nut and washer instead of a cap head screw to keep the shock from sliding off the pin. In th eDR650 world this is a common "upgrade" at the oil filter cap. Instead of threard fasterners in/out o fth ealuminium house everytime yo change the filter you install stell threaded stds in th ealuminium and then use nots to secure the oil filter cap. All but eliminates th epossibility of stripping th ealiminium threads or in this case twisting the head off a fastener. YYMV
-
I've done that several times on differing types of machinery. Including motorcycles with parts (oil pans) that have to be removed often.
-
I have had the most success removing bolts like that by welding a nut to it. The drilling and use of extractors have always been hit and miss.
-
The bolt itself doesn't carry any real load. The special threaded pin that screws into the drive box carries the load. The little Allen-head screw and a washer merely keep the shock from sliding off of the pin. There aren't any active forces pushing it off. The problem is exposure to moisture and corrosive thread locking of the metals. I agree, the screw heads are not very robust. If you round out another Allen head bolt/screw try using a Dremel to cut a nice slot and then a hammer impact wrench to get the bolt out. The hand impact wrench imparts torque and shock impact simultaneously.
Patrick Hayes
Fremont CA
I actually have an impact set. Could have cut a slot, but forgot I owned that set. Doah! I realize the bolt is just a keeper and carries no real load. I plan to replace the button heads with hex head bolts. What's best for this, blue loctite or anti-seize?
In fact that raises a question I've been thinking about posing. When do you use loctite vs. anti-seize vs. dry threads?
-
In fact that raises a question I've been thinking about posing. When do you use loctite vs. anti-seize vs. dry threads?
Not scientific, but what I've gathered over the years:
* Dry - most fasteners that I'm not worried about and/or that have a torque spec which is dry.
* Anti-seize - any fastener that I'm not worried about loosening, but I am worried about locking in place from galvanic corrosion or other factors.
* Threadlock - any fastener that I am worried about loosening (and am not worried the heat will be too much for the compound) and/or a fastener that I'm worried about galvanic corrosion on but also worried and it loosening so I don't really want anti-seize.
-
I would anti-seize it and torque it to spec. using a hex head screw (as you mentioned).
Have you figured out why the bolt was so hard to remove? Poor choice of fastener by manufacturer? Corrosion? Loctite too strong?
-
I would anti-seize it and torque it to spec. using a hex head screw (as you mentioned).
Have you figured out why the bolt was so hard to remove? Poor choice of fastener by manufacturer? Corrosion? Loctite too strong?
Antizeize coupled with torque to spec or it will end up in the fastener being grossly over-torqued. Pick one or the other, not both.
If you look at the bolt in the original picture the original finish was completely gone and the part was rusted. No doubt corrosion was the main cuplrit. In the end it really doesn't matter if it was corrosion, tightened to much, thread lock compound etc. The broken piece has been removed and ready for a new.
-
I tried some supposedly good cheap ones when I first bought the bike. IKON was the brand. Good value they said. Used to be KONI or some such story.
Compression and damping with one adjustment! They SUCKED. I knew in 5 miles I wasted 300 bucks. Point is I spent twice. My error. Buy quality the first time. It's cheaper.
I had a set of IKONS made for my old KZ650 - 21 mm longer than stock with softer than stock springs since I always ride solo. At first they felt harsh, but after setting the rebound to the minimum setting, they worked very well for comfort. Middle of the 3 settings gave ample control for spirited (as spirited as you can get on a bike from the 70s) riding on bumpy roads. Also had a pair intended for the VF1100 Magna fitted to my Honda VT500FT Ascot, again longer than stock for more cornering clearance. They also worked fine. As did the set from a KZ1000 I fitted to my KZ400 (you know by now, more cornering clearance needed). No, they are not Ohlins, but my experience have been positive. And they last a long time, and you can add damping as/when they wear.
When fitted to older big twin Guzzis, however, the IKON/KONI shocks have their limitations from what I have read. For instance, the Mille came with Konis, and they were generally not liked by test riders. It was speculated that the wheel travel of only 70mm was the culprit, or that Koni had not managed to find a shock that could cope with both solo and 2-up riding while offering sufficient comfort with such little travel.
BTW, I believe every basic shock that only have rebound adjuster will also to a small amount affect compression damping. If you want a better ride combined with more control, you are looking at a different price range and more advance designs, most likely.