Badly seized engine bolt
Discussion
I have a badly seized engine bolt on a motorcycle, It's on a HondaCBF500, the engine bolt really is a long shaft with a thread each end and nylock nuts each end.
The 'bolt' is seized where it passes through the engine on one side, it's a steel bolt passing through and aluminium crankcase. Basically the engine hangs from two upper engine bolts and this front seized one holds the front of the engine. There is a three inch space each side between the hanging part of the frame and the crankcase.
I have tried all the normal things, PB Blaster penetrating fluid, air gun, a 3\8 one as I think a 1/2in one is to heavy a knock on it. I have tried heat but the cooling rubber pipes are close by.
I have used a syringe to squirt the penetrating fluid into the spacer, taking the bike for a good run to get it hot and hopefully it seeps in but nothing has happened.
I have seen induction heaters but I cant get close enough to the seized area, and they are dammed expensive. I have also looked for a high frequency device but have not found any thing.
Any suggestions??????
The 'bolt' is seized where it passes through the engine on one side, it's a steel bolt passing through and aluminium crankcase. Basically the engine hangs from two upper engine bolts and this front seized one holds the front of the engine. There is a three inch space each side between the hanging part of the frame and the crankcase.
I have tried all the normal things, PB Blaster penetrating fluid, air gun, a 3\8 one as I think a 1/2in one is to heavy a knock on it. I have tried heat but the cooling rubber pipes are close by.
I have used a syringe to squirt the penetrating fluid into the spacer, taking the bike for a good run to get it hot and hopefully it seeps in but nothing has happened.
I have seen induction heaters but I cant get close enough to the seized area, and they are dammed expensive. I have also looked for a high frequency device but have not found any thing.
Any suggestions??????
It won't be fun. But I've had similar on a motorbike before. I ground down 4 nuts so I could fit 2 on each side of the threaded bar. Heated the bar as much as possible with a torch and turned the whole bar (with the 2 nut method) whilst my mate whacked the other side with a hammer, eventually came loose.
Thanks for the reply's.
Yes it's that long 10mm shaft with the threads each end. One end if free so it's just the other end thats the problem, it is well and truly seized. I have welded a 4mm steel plate on the end of a 10mm nut, then ground it back so i now have a 20mm long nut that only has 10mm of thread that has a blank end, this let's the hammer action of the air gun hammer on the end of the long stud without damaging the threads.
I don't think doing the nut up tight will pull it through, just strip the threads, I will be right up the creek then. It's the spacers that make it difficult.
You have given me an idea though, yes put the normal nut on the seized end with pressure but use my made up nut with the blank end at the other end and use the air gun on it.
Will try that tomorrow.
Yes it's that long 10mm shaft with the threads each end. One end if free so it's just the other end thats the problem, it is well and truly seized. I have welded a 4mm steel plate on the end of a 10mm nut, then ground it back so i now have a 20mm long nut that only has 10mm of thread that has a blank end, this let's the hammer action of the air gun hammer on the end of the long stud without damaging the threads.
I don't think doing the nut up tight will pull it through, just strip the threads, I will be right up the creek then. It's the spacers that make it difficult.
You have given me an idea though, yes put the normal nut on the seized end with pressure but use my made up nut with the blank end at the other end and use the air gun on it.
Will try that tomorrow.
hawkeyefxr said:
Thanks for the reply's.
Yes it's that long 10mm shaft with the threads each end. One end if free so it's just the other end thats the problem, it is well and truly seized. I have welded a 4mm steel plate on the end of a 10mm nut, then ground it back so i now have a 20mm long nut that only has 10mm of thread that has a blank end, this let's the hammer action of the air gun hammer on the end of the long stud without damaging the threads.
I don't think doing the nut up tight will pull it through, just strip the threads, I will be right up the creek then. It's the spacers that make it difficult.
You have given me an idea though, yes put the normal nut on the seized end with pressure but use my made up nut with the blank end at the other end and use the air gun on it.
Will try that tomorrow.
Good plan, let us know how it goes !Yes it's that long 10mm shaft with the threads each end. One end if free so it's just the other end thats the problem, it is well and truly seized. I have welded a 4mm steel plate on the end of a 10mm nut, then ground it back so i now have a 20mm long nut that only has 10mm of thread that has a blank end, this let's the hammer action of the air gun hammer on the end of the long stud without damaging the threads.
I don't think doing the nut up tight will pull it through, just strip the threads, I will be right up the creek then. It's the spacers that make it difficult.
You have given me an idea though, yes put the normal nut on the seized end with pressure but use my made up nut with the blank end at the other end and use the air gun on it.
Will try that tomorrow.
hawkeyefxr said:
TwinKam said:
Love the sachet of Copaslip supplied with that (aftermarket?) kit... if only they were farsighted enough to use that in the factory....
Your right there, i will be using copper slip when i put the new one back but that is stainless so shouldn't need it.Thermal cycling, heat the crankcase boss the stud is in as hot as you can get it with a gas torch then squirt the ends of the stud with freezing spray, repeat several times. If you've got an air hammer I'd have a go at the ends of the stud with that, alternating ends; if not then a hammer and drift will be a reasonable replacement.
hawkeyefxr said:
One end if free so it's just the other end thats the problem, it is well and truly seized.
This bit puzzles me - can you explain exactly what you mean here? How is one end of the shaft seized but the other end isn't? Or do you mean that the nut is seized onto the shaft?Tightening it up against spacers to pull it through would worry me if it's very tightly seized, couldn't that damage the face of the aluminium? Or doesn't that matter?
(It may be obvious that I know nothing about motorcycles or their engines.)
droopsnoot said:
hawkeyefxr said:
One end if free so it's just the other end thats the problem, it is well and truly seized.
This bit puzzles me - can you explain exactly what you mean here? How is one end of the shaft seized but the other end isn't? Or do you mean that the nut is seized onto the shaft?Tightening it up against spacers to pull it through would worry me if it's very tightly seized, couldn't that damage the face of the aluminium? Or doesn't that matter?
(It may be obvious that I know nothing about motorcycles or their engines.)
hidetheelephants said:
From the description the fastener is a stud with a thread at both ends which passes through a hole in the crankcase; corrosion in the hole is gripping the stud very tightly.
I got that, but I don't understand how one end of it seized and the other end isn't.ETA - oh, unless that's a reference to the other stud at the other end of the engine. That's probably it.
Bit late with the replies, sorry.
The long stud passes through the two engine mounts, so one it loose (free) and the other one corroded.
My idea of tightening the seized end up and using the air gun on the other end did not work.
I will take some pictures over the weekend and post them.
The long stud passes through the two engine mounts, so one it loose (free) and the other one corroded.
My idea of tightening the seized end up and using the air gun on the other end did not work.
I will take some pictures over the weekend and post them.
Hope this is explanatory enough. It seems my description has not been exact enough, the stud is 14in (36cm) long with threads each end that are about 1 1/2in in length.
Each end of the stud has a spacer around 3in long each end that fit between the down section of the frame and the radiator hanger. The right hand end is free, not seized, the left hand end is the one that is seized. Hammering on the end of the shaft is a no go as the actual engine mount are quite small and will not take any hammering.
I am carrying on with the penetrating liquid and will see if this works. If it is still seized come the colder weather I will cut the shaft off and drill it out.
Each end of the stud has a spacer around 3in long each end that fit between the down section of the frame and the radiator hanger. The right hand end is free, not seized, the left hand end is the one that is seized. Hammering on the end of the shaft is a no go as the actual engine mount are quite small and will not take any hammering.
I am carrying on with the penetrating liquid and will see if this works. If it is still seized come the colder weather I will cut the shaft off and drill it out.
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