dodgy torque wrench

[flying farmer]

Been doing a cam change on my Rover V8 engined Toledo. Also had to remove the heads and have them machined for dual valve springs.

Putting it all back together I felt that the torque wrench was clicking at a much too low torque.

A while ago when unwinding it for storage I over did it and the end fell off. I suspect that one of the shim washers rolled away out of sight. I had a go at recalibrating it with a spring balance and a length of tube and got it pretty close, but there is a 3-5lb discrepancy between the point where the internal lever start to move and the point where it goes click properly. Since it is probably over 60 years old ( I was given it by my retired Uncle 40 years ago and he was in his 70s) I thought I would treat myself to a new one.

Ended up getting a Halfords professional that does 40- 220lbft. I suspect its a rebadged Norbar since Halfords recommend Norbar for recalibration.

I had done the head bolts up to 60lb with the old wrench but it felt like the bolts were near their proper torque of 65-70.

Tried the new wrench on them set at about 67-68 and about half of them moved a few degrees, the rest didn't so I reckon my guestimated torque was pretty close with the old wrench.

Funny how years of tightening bolts even without a torque wrench gives you a feel for when to stop!

Now I need to recheck the Stag engine head bolts I did recently as I can't quite remember when the end fell off my old torque wrench

Neil

[sujitroy]

I had a click torque wrench from Craftsman here in USA. it fell apart I took it back. Torque wrenches are excluded from there lifetime warranty which I hadn't known. They could repair it but it was cheaper to buy a new one. Now when my elbow clicks I know the nut or bolt is tight enough.

[trunt]

In the old days when we bolted down our CAT scanners we had to take them to 260Nm — I found that my ass is about 250Nm as that’s when it slides along the floor.. to get to 260 I needed to brace on the wall or something!

[richardthestag]

I do a rough check on mine before each day of use by fixing the square socket end in a vice, measuring exactly 1ft from the pivot point and use a spring balance to check click against the spring balance.

I work in ft/lb by the way

Before you ask I calibrate the spring balance with a standard oe kitchen scales weight.

Cheapo torque wrench that operates across a wide range has caused me no end of bother, over torquing at the lower end and under torquing at the upper end. I use that one as a hammer now

[RobinLegin]

Some of the nuts on my Alvis Grey Lady saloon are positioned so as it is very difficult to put a torque spanner on. About half are under the rockers. The answer is an old spanner of about 7 “ in length which allows the nut at the other end to be torqued down using a mathematical formula to reach the correct setting. A good friend and fellow Alvis owner came by and helped. He just used a spanner and knew when he reached the correct setting.

when he’d left I went around all the nuts on the cylinder head using my “adapter” and found everyone of them correctly torqued. My friend used to be Alvis’ chief engineer.

[MikeParker]

I treated myself to a new click-type torque wrench recently, just before torquing up a stag head. So I merrily torqued up the head bolts and studs, but it didn't feel right. I checked them against an old bendy-bar type torque wrench and low and behold the torques were way too low. I was just about to return the click wrench when I fortunately noticed it had two scales - Nm and ft-lbs. I had of course used the wrong scale. So beware!