Use of heat to free up rusted on and stubborn nuts
Discussion
I need to separate the drive/half shafts in order to remove the hub carriers.
Clearly, the nuts and bolts haven't been touched in over 35 years and they appear to be well and truly stuck.
The removal isn't helped by the fact that only the bolts can be undone (the nuts are sat up against a lip) and they use an 8mm Hex socket.
Apparently, cutting the nuts off isn't uncommon but this is a last resort.
I've never used heat on seized nuts before, will a Plumbers blow torch be OK? I only ask because whenever I've seen heat used in these situations a rather spindly/fine nozzle has been used to apply the heat. A domestic blow torch will give a much wider spread of heat, however it is adjusted.
Clearly, the nuts and bolts haven't been touched in over 35 years and they appear to be well and truly stuck.
The removal isn't helped by the fact that only the bolts can be undone (the nuts are sat up against a lip) and they use an 8mm Hex socket.
Apparently, cutting the nuts off isn't uncommon but this is a last resort.
I've never used heat on seized nuts before, will a Plumbers blow torch be OK? I only ask because whenever I've seen heat used in these situations a rather spindly/fine nozzle has been used to apply the heat. A domestic blow torch will give a much wider spread of heat, however it is adjusted.
Edited by Andy 308GTB on Sunday 13th December 08:23
I've used normal blowtorches for years on rusted nuts & usually no problems.
Currently one of these although I think you can get some with finer nozzles: http://www.diy.com/departments/at2071h-gosystem-bl...
Obviously be careful using them next to things that can be damaged by heat/set on fire!
Worth keeping a bucket of water or a hosepipe to hand.
You could try Loctite Freeze and Release, I use that too & it's good.
I'd love one of the induction heaters but for occasional use I can't justify the expense.
Currently one of these although I think you can get some with finer nozzles: http://www.diy.com/departments/at2071h-gosystem-bl...
Obviously be careful using them next to things that can be damaged by heat/set on fire!
Worth keeping a bucket of water or a hosepipe to hand.
You could try Loctite Freeze and Release, I use that too & it's good.
I'd love one of the induction heaters but for occasional use I can't justify the expense.
Edited by paintman on Sunday 13th December 09:49
Andy 308GTB said:
.
Apparently, cutting the nuts off isn't uncommon but this is a last resort.
Why? Are the bolts something special? The nuts look odd, some sort of self locking?Apparently, cutting the nuts off isn't uncommon but this is a last resort.
Edited by Andy 308GTB on Sunday 13th December 08:23
If not, can you get a cutting disc to either end? And space to use a drift to knock the shank out?
John
Have you tried them? Although there's some rust underneath it looks like it's been sitting in a nice coating of grease/oil which will aid removal. There's something to be said for a constant oil leak, keeps the rust away!
As for penetrating oil, get a squirting oil can and fill it with a mix of 50/50 Acetone and Transmission fluid. Shake before use and squirt it in there. It's ten times better than any proper off the shelf penetrating fluid I've ever used, just avoid ABS plastics.
Heating wise when all else fails I use a Plumbers torch (Rothenberger Super Fire 2) with MAP gas, small enough nozzle (but not oxy small) and a lot hotter than propane/butane etc.
As for penetrating oil, get a squirting oil can and fill it with a mix of 50/50 Acetone and Transmission fluid. Shake before use and squirt it in there. It's ten times better than any proper off the shelf penetrating fluid I've ever used, just avoid ABS plastics.
Heating wise when all else fails I use a Plumbers torch (Rothenberger Super Fire 2) with MAP gas, small enough nozzle (but not oxy small) and a lot hotter than propane/butane etc.
Edited by Mroad on Sunday 13th December 11:41
A pinpoint of heat isn't needed, strictly speaking. I've used a Ronson domestic blowtorch-thing for years with great success.
I was always taught that the idea is to expand and crack the rust seal, so the heat is aimed at the bolt, not the nut. This makes the bolt expand inside the nut and break the bond before the heat soaks into the nut. Application of penetrating fluid whilst still hot can cause it to be drawn into the joint as it contracts making the job even easier.
I was always taught that the idea is to expand and crack the rust seal, so the heat is aimed at the bolt, not the nut. This makes the bolt expand inside the nut and break the bond before the heat soaks into the nut. Application of penetrating fluid whilst still hot can cause it to be drawn into the joint as it contracts making the job even easier.
Multiple soakings in Plus Gas was my first step...
Yup, I've tried a breaker bar with a 1/2" 8mm Hex fitting and they won't budge.
I wasn't exactly hanging on the end of the breaker bar because I was concerned I would round out the bolt socket.
The guy, who told me that cutting the nuts off can sometimes be necessary, was a well respected marque mechanic & garage owner with donkey's years of experience.
As mentioned in my first post, the nuts are trapped by a lip, so the first 1/4" of movement/undoing has to be done by turning the bolt.
Yes, the nuts are a bit special - I think the extra bits are to lock them down a bit more than just the nut thread. (Are these called 'tapered nuts'?)
Yup, I've tried a breaker bar with a 1/2" 8mm Hex fitting and they won't budge.
I wasn't exactly hanging on the end of the breaker bar because I was concerned I would round out the bolt socket.
The guy, who told me that cutting the nuts off can sometimes be necessary, was a well respected marque mechanic & garage owner with donkey's years of experience.
As mentioned in my first post, the nuts are trapped by a lip, so the first 1/4" of movement/undoing has to be done by turning the bolt.
Yes, the nuts are a bit special - I think the extra bits are to lock them down a bit more than just the nut thread. (Are these called 'tapered nuts'?)
Appears they are called 'split type' locknuts. AKA split beam.
The nuts are held by their location so aren't going anywhere.
The bits at the top are bent in slightly & grip the thread of the bolt.
Pics here, although I wonder if they've been superseded as there are 2 listed.
http://www.superformance.co.uk/308/driveshaft.html
The nuts are held by their location so aren't going anywhere.
The bits at the top are bent in slightly & grip the thread of the bolt.
Pics here, although I wonder if they've been superseded as there are 2 listed.
http://www.superformance.co.uk/308/driveshaft.html
paintman said:
Appears they are called 'split type' locknuts. AKA split beam.
The nuts are held by their location so aren't going anywhere.
The bits at the top are bent in slightly & grip the thread of the bolt.
Pics here, although I wonder if they've been superseded as there are 2 listed.
http://www.superformance.co.uk/308/driveshaft.html
Thanks for the info on the type of nut.The nuts are held by their location so aren't going anywhere.
The bits at the top are bent in slightly & grip the thread of the bolt.
Pics here, although I wonder if they've been superseded as there are 2 listed.
http://www.superformance.co.uk/308/driveshaft.html
Eurospares still list the lock nuts too (but at a more reasonable price!)
So cutting them off isn't the end of the world but would be a major p.i.t.a.
Andy 308GTB said:
paintman said:
Appears they are called 'split type' locknuts. AKA split beam.
The nuts are held by their location so aren't going anywhere.
The bits at the top are bent in slightly & grip the thread of the bolt.
Pics here, although I wonder if they've been superseded as there are 2 listed.
http://www.superformance.co.uk/308/driveshaft.html
Thanks for the info on the type of nut.The nuts are held by their location so aren't going anywhere.
The bits at the top are bent in slightly & grip the thread of the bolt.
Pics here, although I wonder if they've been superseded as there are 2 listed.
http://www.superformance.co.uk/308/driveshaft.html
Eurospares still list the lock nuts too (but at a more reasonable price!)
So cutting them off isn't the end of the world but would be a major p.i.t.a.
I'd cut the Cap head end off not the recessed nut - thin slitting disc and a mm away from the seat and they'd be toast for a centre punch extract
I wouldn't want to put too much heat near the rubber gaiters if the bolts and nuts are avaliable I'd choose replacement every time
PS Unusual arrangement - never seen that before
E-bmw said:
I might be missing the obvious, but, looking at the condition of the nuts, they look perfect to me & I can't understand why they won't take some SERIOUS force to loose them off.
I have certainly removed much worse without any assistance above a socket set/breaker bar.
The nuts are held in position by the adjacent metalwork so can't be undone by just putting a socket on them. Needs to be undone from the cap end. OP is concerned about rounding the inside of the cap.I have certainly removed much worse without any assistance above a socket set/breaker bar.
Andy308GTB said:
The removal isn't helped by the fact that only the bolts can be undone (the nuts are sat up against a lip) and they use an 8mm Hex socket.
Edited by paintman on Wednesday 16th December 01:17
They probably just need shocking free, can you get a gun onto the bolt heads (is there room) if not give your breaker bar a good solid whack with a heavy mallet a few times. Then hang off the end of it, you really don't have much to lose as if they round off you'll be out with the grinder anyway,
As others have said, they look in great condition - so long as you get square on to the bolts there's no reason why they shouldn't loosen with a bit of force. I'd avoid using too much heat from a torch as you don't want to damage the rubber gaiters.
As others have said, they look in great condition - so long as you get square on to the bolts there's no reason why they shouldn't loosen with a bit of force. I'd avoid using too much heat from a torch as you don't want to damage the rubber gaiters.
As others have said I've used MAP gas with a plumbers torch before. If your worried about getting the flame on things in close proximity I have used a protective heat mat. De-grease before hand to reduce the smoke created. The nuts being at the opposite end to the boot you shouldn't damage that with heat. The nuts really need to be very hot before heating has any benefit!
If the output shaft is quite short / close to the differential or transaxel just be careful not to put a flame too close to the lip seal.
If the output shaft is quite short / close to the differential or transaxel just be careful not to put a flame too close to the lip seal.
Yes. it's the fact that they can only be removed with an 8mm Hex socket that is the worry. Plus the fact that a very experienced Ferrari mechanic has told me that even he sometimes has to cut them off - that makes me think this isn't going to be a walk in the park.
But the fact of the matter is...
But the fact of the matter is...
Blaster72 said:
...you really don't have much to lose as if they round off you'll be out with the grinder anyway
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