Torque wrench how to question

[Esel Mann]

Originally Posted by island911

This ^

A 200 lb person stand on a 1.5-ft bar will do it too.

Alternatively two 100lb strippers with 1.5 ft of their dance pole cut out would go well beyond satisfying the minimal requirements and permit the OP to simply supervise the task.
Hehe, it's important to not overthink this....

[GH85Carrera]

For the nut on the rear axle of my 911 the torque value is some crazy number like 360 pound feet. I would have to look it up to get the exact number and it is irrelevant right now.

I stood on a scale, and pushed down on a 3 foot bar until I weighted the proper amount on the scale. Again, I don't remember the numbers, as it does not matter. I then knew I was pretty close, but I don't do "good enough" when it comes to holding my rear axle on. I brought my socket to a local truck stop and pulled up by the work bays. Of course an old guy in a 85 911 with a $20 bill in hand attracted some attention. One mechanic walked over and I told him I would give him the 20 if he would torque the two nuts to the proper number. He grabbed his 4 foot long torque wrench, and click click twice and he made 20 bucks. I went home and put the cent caps back on and I was done.

[aschen]

I think 300ft lbs is right on the edge of most half inch drives capacity. Can grab a decent ratchet and torque til it breaks and you will be close

if you have the right 3/4 drive socket and breaker bar you can get something like this for relatively reasonable amount. https://www.amazon.com/Neiko-20743A-Digital-Adapter-Foot-Pound/dp/B009GLITFW/ref=sr_1_2?dchild=1&keywords=torque+adapter+3%2F4&qid=1632147711&sr=8-2

[matthewb0051]

Originally Posted by Esel Mann

Alternatively two 100lb strippers with 1.5 ft of their dance pole cut out would go well beyond satisfying the minimal requirements and permit the OP to simply supervise the task.
Hehe, it's important to not overthink this....

Do the strippers need to be clothed or is your math based on them at the end of their act?

I have a DeWalt 20v impact. Used it for axel nuts that are around the same torque. Prior to that it was a 3/4 drive socket and 3.5 ft breaker bar with my fat ass standing on it.

[speeder]

Any really strong impact wrench should do it. You would need to torque it to 250, or however tight you can accurately get it with your wrench, mark the bolt with paint and then blast it with an impact that moves it a hair. Just a hair, at those torques. Threads only stretch so much.

The suggestions about having strippers or 4 German Shepards standing on a pipe assume that there is no friction to overcome in initially moving the fastener. That is an incorrect assumption.

[speeder]

Originally Posted by GH85Carrera

For the nut on the rear axle of my 911 the torque value is some crazy number like 360 pound feet. I would have to look it up to get the exact number and it is irrelevant right now.

I stood on a scale, and pushed down on a 3 foot bar until I weighted the proper amount on the scale. Again, I don't remember the numbers, as it does not matter. I then knew I was pretty close, but I don't do "good enough" when it comes to holding my rear axle on. I brought my socket to a local truck stop and pulled up by the work bays. Of course an old guy in a 85 911 with a $20 bill in hand attracted some attention. One mechanic walked over and I told him I would give him the 20 if he would torque the two nuts to the proper number. He grabbed his 4 foot long torque wrench, and click click twice and he made 20 bucks. I went home and put the cent caps back on and I was done.

This is the winning post and what I've done in the past for axle nuts but those are easy because you can get them part of the way tight and then drive to a tire shop or somewhere with a huge torque wrench. It's a little tougher with a crankshaft bolt.

[gordner]

Originally Posted by speeder

Any really strong impact wrench should do it. You would need to torque it to 250, or however tight you can accurately get it with your wrench, mark the bolt with paint and then blast it with an impact that moves it a hair. Just a hair, at those torques. Threads only stretch so much.

The suggestions about having strippers or 4 German Shepards standing on a pipe assume that there is no friction to overcome in initially moving the fastener. That is an incorrect assumption.

So if that is true, how does a torque wrench set for the correct value account for that any more than the strippers or dogs do?

The torque value is given with drag torque included. Where it is not, then it would have to be measured and added to the total torque, and the torqueing procedure would indicate that.

[RANDY P]

TQ wrenches aren't exactly accurate at the top of the scale they are rated for. Min / Max tq. measuring capacity +/-20% IIRC.

I'd seek a tool rental place out, frankly.

rjp

[speeder]

Originally Posted by gordner

So if that is true, how does a torque wrench set for the correct value account for that any more than the strippers or dogs do?

No, they do not. If a fastener is already tight, (i.e. anywhere close to final torque), it needs to be loosened slightly and then torqued. Torque wrenches absolutely do not account for initial friction and would *click* below final torque in that circumstance. They are made to measure while moving.

[A930Rocket]

I’ve always read the bottom and top scales of the torque wrench are not as accurate. That said, I torqued it to 250 and then used my breaker bar with a 3 foot cheater bar to move it a little more.

[1990C4S]

Speeder is correct. Torque a moving bolt, not a tightened bolt. And adding lube for good measure may not be advisable.

The accuracy is typically a percent of full scale. So you want to use your torque wrench near the top of its range. The top end is the more accurate region.

[KFC911]

Originally Posted by 1990C4S

...

The accuracy is typically a percent of full scale. So you want to use your torque wrench near the top of its range. The top end is the more accurate region.

Is this accurate? I've always tried to pick a torque wrench where the "desired" torque is in the middle of the wrench's range and not the upper end... but I dunno.

[1990C4S]

I will modify my statement to say 'it depends on the wrench'. Read the docs that came with your wrench.

What I stated is 'typical'. So it might be both accurate and repeatable...

[KFC911]

Originally Posted by 1990C4S

I will modify my statement to say 'it depends on the wrench'. Read the docs that came with your wrench.

What I stated is 'typical'. So it might be both accurate and repeatable...

I'm gonna have to take your word for it.... what docs ?

I have 20 year old Craftsman TWs ... anyone know about them?

Learned something new.... thanks!

[David]

I'm surprised that BMW would have torque value like that rather than a pre-torque value and then a turn X degrees number. That's what modern Porsche's do for flywheels and such.

Torque wrenches aren't super accurate for determining bolt stretch anyway. You could calculate the turn by degree method with the thread pitch and desired bolt stretch.

[gtc]

Just give it 7 Ugga Duggas and you should be fine.

[hcoles]

Originally Posted by speeder

No, they do not. If a fastener is already tight, (i.e. anywhere close to final torque), it needs to be loosened slightly and then torqued. Torque wrenches absolutely do not account for initial friction and would *click* below final torque in that circumstance. They are made to measure while moving.

This is correct.