240 General: New (to me) 1980 Volvo 244

[Laird Scooby]

Originally Posted by Othen

Wow! Dave, that is impressive.

Alan

The not so impressive fact is that once it had loosened the nut, the nut then went tight on the thread without me realising so i continued to the point where the bolt just sheared! Live and learn!

[Laird Scooby]

Duplicate post - oops!

[Othen]

Originally Posted by Othen

I have a bit of spare time towards the end of the week Dave, so I may set up an experiment on the bench with a large nut and bolt done up to a known torque in the vice to see whether the 330Nm impact driver (or indeed the DeWalt) can unfasten it.

I'm guessing that little gadget of yours has some gears inside it to give a mechanical advantage? It looks cool, but is a bit pricey for me (the 4' length of fence post does exactly the same thing).

I absolutely agree about loosening wheel nuts/bolts after the garage has fitted them and torqueing them up properly. I have learned that after last week's issue with the Skoda - fortunately I didn't get a roadside puncture!

Alan

I got round to testing my old, unbranded impact driver and my new DeWalt today. First I had to construct this scientific rig:



... as you may see it is just a redundant towing hook clamped in my bench vice. I needed something with some sizeable nuts and bolts (these look like about M18) and some flat sides so I could clamp it safely.

I used my torque wrench to tighten the nut up to 140Nm first. The unbranded driver (rated at 330Nm remember) undid it without too much fuss:



I repeated the same test with the DeWalt, which also unfastened it easily:



Next I tightened the nut up to 180Nm. The unbranded tool struggled but did eventually rattle the nut off. The DeWalt was similar - perhaps a little easier.

At the 200Nm the unbranded tool failed to unfasten the nut - lots of hammering and noise but no movement. The DeWalt struggled but did eventually undo the nut.

Finally I tried the same test at 210Nm (the highest setting on my torque wrench) - and the DeWalt also failed to move the nut.

So, much as I thought, they must use either different Newtons or different metres in the two Chinese factories these tools originated from. The unbranded one certainly isn't capable of producing 330Nm of torque, its limit is (much as I had estimated last week) about 180Nm. The DeWalt slightly out-performed its rated torque, so I'm happy with that.

I ought to get out more :-)

Alan

[Laird Scooby]

Interesting stuff Alan! Am i right in thinking your "non-brand" wrench doesn't have an LED to illuminate the work piece?

Your test has inspired me to hunt out my towball and bolts (M16, 24mm heads) and try a development of your test.

Short version would be to dip the bolts in engine oil (i've got some useless engine oil that would be perfect for this) before assembly and torquing to 200-250lbft.
Then give it the blowlamp treatment to carbonise the oil and once cool, try the impact wrench i have and also the torque multiplier as i can drive that with a torque wrench to see exactly how much it takes to loosen the nut.

The idea is this will simulate ageing and oil getting on the various fasteners.

[Burdekin]

I have a similar attachment for my impact driver but it doesn’t have anywhere near the same amount of grunt (torque) as a good impact wrench. The Dewalt impact wrenches are beasts and a different animal to the impact drivers.

[morwenna240]

I confess i don't like the idea of impact drivers at all, way too viscious. i use heat on stubborn nuts. warm them up as mutch as is safe for the site, then dash cold water on, the sudden shrinkage breaks the rust. There is also a very effective releasing spray called Rocket something, way better than WD40 or Plus gas.

The tyre place i go to bans the use of impacts by his employees, all wheelnuts go on an off with those four sided spin wrenches. There is a breaker bar on the rack, but i've never seen them use it.

[Othen]

Originally Posted by Burdekin

I have a similar attachment for my impact driver but it doesn’t have anywhere near the same amount of grunt (torque) as a good impact wrench. The Dewalt impact wrenches are beasts and a different animal to the impact drivers.

I’m trying to justify buying a DeWalt torque wrench to myself, there is one particular model that is rated at 900Nm that seems an absolute beast. The cost is around £150 for the bare tool (the batteries I have with the driver and drill would fit), which is not such an issue but I really wonder how often I’d need more than 200Nm. The only application I can think of (apart perhaps from the odd rusted on fastener) is the hub nuts on FWD motor cars - which happens perhaps biennially. It would be really difficult to justify (to myself) buying a tool I’d use so infrequently - it does look cool though!

:-)

[Othen]

Originally Posted by Othen

I’m trying to justify buying a DeWalt torque wrench to myself, there is one particular model that is rated at 900Nm that seems an absolute beast. The cost is around £150 for the bare tool (the batteries I have with the driver and drill would fit), which is not such an issue but I really wonder how often I’d need more than 200Nm. The only application I can think of (apart perhaps from the odd rusted on fastener) is the hub nuts on FWD motor cars - which happens perhaps biennially. It would be really difficult to justify (to myself) buying a tool I’d use so infrequently - it does look cool though!

:-)

I meant 'impact wrench' and not 'torque wrench' in the above... my fat fingers :-)

Alan

[Burdekin]

Originally Posted by Othen

I’m trying to justify buying a DeWalt torque wrench to myself, there is one particular model that is rated at 900Nm that seems an absolute beast. The cost is around £150 for the bare tool (the batteries I have with the driver and drill would fit), which is not such an issue but I really wonder how often I’d need more than 200Nm. The only application I can think of (apart perhaps from the odd rusted on fastener) is the hub nuts on FWD motor cars - which happens perhaps biennially. It would be really difficult to justify (to myself) buying a tool I’d use so infrequently - it does look cool though!

:-)

I have a old air one but would like a battery one. My problem is my battery tools are the old Erbauer ones from Screwfix which are still going strong so I’d also need to buy a battery and charger. Wish all battery tools had to have the same battery connections.

[Laird Scooby]

Originally Posted by Burdekin

I have a old air one but would like a battery one. My problem is my battery tools are the old Erbauer ones from Screwfix which are still going strong so I’d also need to buy a battery and charger. Wish all battery tools had to have the same battery connections.

Many of the new cordless tools use a common battery platform so Makita batteries can be used in De Walt and in the cheap unbranded Chinese stuff and vice versa - there are more, those are just three of the ones i've come across that have claimed cross-compatibility.

In other words, if you can't repair the dead batteries in your Erbauer tools when they die (replacement batteries are available in single-cell form on ebay so you can create a battery of cells) then buying new isn't such a bad idea.

Still goes against the grain to advise to buy new when the old ones are serviceable or would be with new batteries but you get the idea!