Do you use a torque wrench or go by feel?
Discussion
HustleRussell said:
My Dad is a proper time served mechanic and has great feel for how tight things should be. He only resorts to a torque wrench when it comes to things like head bolts. I would love to have this skill. I do use a torque wrench for wheel nuts.
Can't think where I saw it recently but someone was saying for Goodness sake don't use a torque wrench on things like spark plugs and sump bolts that have a crush washer - it's much better to do them by feel. I guess that depends on whether you have the "feel" or not!I was surprised when using quite a well regarded indie tyre place that they did the tightening by hand and without a torgue wrench. I thought these days "duty of care" type stuff would make them at least go through the motions.
Re head bolts - not that I've ever done one, but aren't they usually tightened by angle?
Sheepshanks said:
HustleRussell said:
My Dad is a proper time served mechanic and has great feel for how tight things should be. He only resorts to a torque wrench when it comes to things like head bolts. I would love to have this skill. I do use a torque wrench for wheel nuts.
Can't think where I saw it recently but someone was saying for Goodness sake don't use a torque wrench on things like spark plugs and sump bolts that have a crush washer - it's much better to do them by feel. I guess that depends on whether you have the "feel" or not!I was surprised when using quite a well regarded indie tyre place that they did the tightening by hand and without a torgue wrench. I thought these days "duty of care" type stuff would make them at least go through the motions.
Re head bolts - not that I've ever done one, but aren't they usually tightened by angle?
Anything with a crush washer you're more likely to get right by hand, but again the manufacturer spec will take it into account.
Head bolts could be different depending how much yield the manufacturer has specced in, some are torque then angle, just torque or a mix inbetween.
Ona similar vein - reusing bolts. Fine in a lot of cases, I made the mistake of reusing some bolts which held the turbo to the old feed. Turns out they were torque to yield (so a torque plus a specific angle), the old stretched bolts were over 2mm longer than the new ones, and simply didnt have the right clamping force to hold the oil feed securely.
On anything critical, I am a torque nazi. Values and sequences are there for a reason.
On anything critical, I am a torque nazi. Values and sequences are there for a reason.
105.4 said:
F20CN16 said:
If the correct torque settings are available in a haynes or other workshop manual, I just can’t see why you wouldn’t! I like to take the guess work out. It’s usually stressful enough working on cars.
Be careful of the stated torque settings in the Haynes Book of Lies. I’ve learnt from (costly) personal experience that the torque settings stated in Haynes aren’t always correct.rambo19 said:
The rest by feel, as taught to me by my dad.
He trained as a mechanic from the age of 15 and could get to +/- 5lbs with feel.
How did your Dad teach you? Was it a case of you watching him tighten it and then putting the spanner / bar on it afterwards and feeling it? He trained as a mechanic from the age of 15 and could get to +/- 5lbs with feel.
Dad races an old Formula Junior and I’d no sooner do the final tightening on any fixings on that car than I would a light aircraft. I used to be an over-tightener and all of the fixings on this car, being a Lotus, are exactly as big as they need to be and no bigger. I think the wheel studs are 5/16” and the tightening torque for those is no more than 30lb.ft- a disconcertingly low torque for putting a wheel on, especially when you know that your Dad is going to go straight out on it and do 130mph. It is not a safe car being a 1962.
Ayahuasca said:
I have changed lots of wheels, and never used a torque wrench and never had a wheel come off. Has anyone ever had a wheel come off because they didn't use a torque wrench?
The wheel coming off is not the only thing that can go wrong. I have a friend who is about 23 stone and used to tighten wheel bolts by bouncing on the wheel brace. He didn’t have any problems at all until the first time he had to remove a wheel he had fitted- all of the bolts sheared off in the hub and it cost him a few hundred to have put right.
This is on the risk of turning into one of those classic pedantic threads.
I say do what works for you. For me, I'll happily do many bolts up without a torque wrench with confidence, but there's also some, perhaps many, that get the torque wrench too. Wheel bolts, sump bolts into an alloy casting, head bolts, cam cap bolts, main & big end caps and so forth are examples that do get the treatment.
I say do what works for you. For me, I'll happily do many bolts up without a torque wrench with confidence, but there's also some, perhaps many, that get the torque wrench too. Wheel bolts, sump bolts into an alloy casting, head bolts, cam cap bolts, main & big end caps and so forth are examples that do get the treatment.
Assuming you can find a torque spec, and have a wrench for it, why wouldn't you just torque to spec?
Most of the time I'm sure it doesn't matter, and pretty much any garage will never use a TW except for engine components etc... But if it's there and you've got the equipment then why not?
I'd also add that some items are a bit unusual and presumably that's done for a reason, but unless you checked the specs you couldn't know.
Most of the time I'm sure it doesn't matter, and pretty much any garage will never use a TW except for engine components etc... But if it's there and you've got the equipment then why not?
I'd also add that some items are a bit unusual and presumably that's done for a reason, but unless you checked the specs you couldn't know.
An odd thing on wife's 4Motion Tiguan is the wheel bolts are lower torque than the 2WD version - tyre places never have both specs and always want to do them to 140Nm, when the handbook says 120Nm.
I've seen it queried on VW forums but no-one has ever been able to explain why.
In practice the angle difference is tiny but I do wonder if the bolts have been stretched. It's the one car we have where I make a point of rechecking them a couple of days after the wheels have been off.
I've seen it queried on VW forums but no-one has ever been able to explain why.
In practice the angle difference is tiny but I do wonder if the bolts have been stretched. It's the one car we have where I make a point of rechecking them a couple of days after the wheels have been off.
devnull said:
Ona similar vein - reusing bolts. Fine in a lot of cases, I made the mistake of reusing some bolts which held the turbo to the old feed. Turns out they were torque to yield (so a torque plus a specific angle), the old stretched bolts were over 2mm longer than the new ones, and simply didnt have the right clamping force to hold the oil feed securely.
On anything critical, I am a torque nazi. Values and sequences are there for a reason.
I've re-used head bolts after measuring : the factory manual gives a length spec to check if they've stretched too much.On anything critical, I am a torque nazi. Values and sequences are there for a reason.
I have various torque wrenches of varying ranges from something like 2Nm up to 200Nm. The smallest one is because of aluminium machine screws... yes, that is a thing. Thank you, Mercedes.
I use torque wrenches for anything where getting it wrong would be a safety issue, and anything where I think I could knacker the threads if I don't.
I don't generally use a torque wrench for anything where I had to use a breaker bar in full gorilla mode, but rather do the fastener back up to the same FT setting.
On the point of using a breaker bar, I found that a very useful addition is a ratchet so you can manoeuvre it to the ideal spot to put some welly in. You can buy big breaker bars with a built-in ratchet, you can buy retrofit knuckles, and you can also buy a 1/2" ratchet adapter. The latter is what I use but I am thinking about just getting a retrofit knuckle to reduce the offset.
I use torque wrenches for anything where getting it wrong would be a safety issue, and anything where I think I could knacker the threads if I don't.
I don't generally use a torque wrench for anything where I had to use a breaker bar in full gorilla mode, but rather do the fastener back up to the same FT setting.
On the point of using a breaker bar, I found that a very useful addition is a ratchet so you can manoeuvre it to the ideal spot to put some welly in. You can buy big breaker bars with a built-in ratchet, you can buy retrofit knuckles, and you can also buy a 1/2" ratchet adapter. The latter is what I use but I am thinking about just getting a retrofit knuckle to reduce the offset.
HustleRussell said:
Ayahuasca said:
I have changed lots of wheels, and never used a torque wrench and never had a wheel come off. Has anyone ever had a wheel come off because they didn't use a torque wrench?
The wheel coming off is not the only thing that can go wrong. I have a friend who is about 23 stone and used to tighten wheel bolts by bouncing on the wheel brace. He didn’t have any problems at all until the first time he had to remove a wheel he had fitted- all of the bolts sheared off in the hub and it cost him a few hundred to have put right.
There's little in the world more satisfying than the click of torque wrench (fans of M539 Restorations will know what I mean).
I usually double check online the value(s) quoted in the Haynes manual.
Sheepshanks said:
Can't think where I saw it recently but someone was saying for Goodness sake don't use a torque wrench on things like spark plugs and sump bolts that have a crush washer - it's much better to do them by feel. I guess that depends on whether you have the "feel" or not!
I do spark plugs and oil pan bolts by hand. Everything else I'll use a torque wrench.I usually double check online the value(s) quoted in the Haynes manual.
Gassing Station | Home Mechanics | Top of Page | What's New | My Stuff