torque wrench trick?

[robsGS850]

Any cool McGyver tip if your torque wrench isn't rated high enough for the job at hand? I'm guessing I need a new wrench, but hey, you never know...

thanks all

 

[marvinsc]

I had a 1/2" drive Torque wrench returned to the Tool Crib Bent once, I don't think that is the proper technique.*

 

[Mark M]

Any cool McGyver tip if your torque wrench isn't rated high enough for the job at hand? I'm guessing I need a new wrench, but hey, you never know...

thanks all

Depends a bit on what you are tightening. Usually, if you are off the top of the scale being dead accurate is less important than down at the bottom end with the small fasteners. At least you are unlikely to strip or break the large fasteners.

How much torque do you need and what are you tightening?

Mark

 

[rustybronco]

A piece of steel bar stock with a square drive welded to it for the socket to attach and a square hole in the other end to accept the torque wrench.
it would be easiest if the length was the same as from the center of the square drive portion of your torque wrench to where the handle is "pivoted" in the torque wrench, then just double the reading.

 

[SPARKSS]

Any cool McGyver tip if your torque wrench isn't rated high enough for the job at hand? I'm guessing I need a new wrench, but hey, you never know...

thanks all

Hello Rob. Here's 2 good methods of doing exactly what you're asking, that I know of.....and a trick....there may be others. The first concerns using a torque adapter (which could be a wrench) and will do what you're asking. The usual use of this idea+calculation is to accommodate a particular turning end for the torque wrench - See this link for good details:

http://www.engineersedge.com/manufacturing_spec/torque_wrench_1.htm


The second method involves using a gear multiplier. These are available in several torque input/output sizes and ratios. Typical ones are X4 and X6 but I've seen 'em up to X16, and for use with torque input down to 3/8" sq drive.
These, however are expensive, and are generally used in shops that may occasionally require torque above their largest wrench. They're also used for general bolt turning without torque wrenches (not impact).

Note with this latter method, that the torque wrench figure multiplied IS NOT the gear multiplication but is a figure somewhat less (the manufacturer will state this) - due to loss in the mechanisim. For example, an X4 (4:1) multiplier may have a torque ratio of 3.4:1.

A third "trick".....depending on how much higher torque is needed is to lube the threads of the fastener to effect a higher clamping force for the same amount of torque applied. IN SOME CASES this may be acceptable and can lower the input torque significantly - one example I was just working on advised that lubing a particular thread with SAE30 oil lowered the torque required by 20-23% to achieve the same clamping force. This method, however will require some research and testing of similar size fasteners and materials to get an idea of how much reduction you'd effect, for the same clamping force.

That's all I've got.

 

[drhach]

Any cool McGyver tip if your torque wrench isn't rated high enough for the job at hand? I'm guessing I need a new wrench, but hey, you never know...

thanks all

I've always figured that if the OEM took the time to pay an engineer to determine the proper torque wrench settings, they probably are important. So, if it was me, I'd buy the right torque wrench and not half-a$$ it. Also, you can never have too many cool tools, so now you have an excuse to get more stuff.

 

[Steve]

What is it you are trying to torque, and what wrench is it off the scale of?

I went to the local Harbor Freight and got all three wrenches they had to offer. I now have a 1/4" drive, a 3/8" drive and a 1/2" drive.
Got all three for a total of about $50, so it's not all that expensive to get a tool that is at least close to right.
Harbor Freight might not have the best tools around, but they are probably closer than my guessing at torque values.

.

 

[robsGS850]

wow thanks for all the great advice.

i have a slow leak around my base gasket (again) so when i'm in there adjusting the valves this weekend I'm gonna try the old re-torque the cylinder nuts (I think they're called). 12 of them, rated at some really high torque (forget exactly) my wrench just about goes that high, but not quite (goes about 4/5ths of the way)

Figure with something this key and since im already fighting a leak, gotta do it right. No Harbour Freight in Canada but there is a Princess Auto, famous for cheap tools from Taiwan...

thanks again

 

[Mark M]

Figure with something this key and since im already fighting a leak, gotta do it right. No Harbour Freight in Canada but there is a Princess Auto, famous for cheap tools from Taiwan...

thanks again

For head studs, get it right. Don't forget CT (Canadian Tire) and House of Tools for this stuff as well.

Mark

 

[catbed]

get a foot-long wrench and hang how ever much weight your tightening it to to the end. like 27 pounds for 27 ft-lbs. (ten points to whoever guesses what that torque goes to)

or you could tighten it until it strips, then back it off a quarter turn.

edit: new smilies????

 

[Switchman]

Before you attempt to tighten this bolt again.... do a search and see how many references you can find for broken bolts, studs, and stripped threads. Also, take a look here: http://en.wikipedia.org/wiki/Bolted_joint
Doing it properly, a fastener can be torqued once and only once to the specified value. You are literally stretching the bolt against the holding threads to an engineered tension based on material science. Exceed those values past whatever the built in margin is and SNAP. You CANNOT retorque a previously torqued fastener and expect to know what is going to happen.
The gasket also has to be figured in. It is made to crush to a certain point.
If your gasket is weeping a bit...just keep it clean. If it is blowing oil then it is torn...change it...as well as ALL specifically torqued studs and bolts.

 

[SqDancerLynn1]

I have one of those $20 Harbor Freight 3/4 ratchets you can have -- Only used one time, Slightly bent

 

[Shaughn]

The only time I ever was over the reach of a standard 1/2" torque wrench was a the axle nut on a front wheel drive car...Are you sure you're not confusing in-lbs with ft-lbs? Makes a big difference. In any case, if you care enough to trust torque settings over your gut/wrist, go buy the right tool for the job. It's almost always cheaper in the long run to do so.

get a foot-long wrench and hang how ever much weight your tightening it to to the end. like 27 pounds for 27 ft-lbs. (ten points to whoever guesses what that torque goes to)

or you could tighten it until it strips, then back it off a quarter turn.

edit: new smilies????

25-29 ft. lbs is the cylinder head nuts on my 78 '750... door prize?

Shaughn
77 '750E (9/77)

 

[salty_monk]

I have a 3/8" one also from Harbor freight. Goes up to 80ftlb I think, maybe more. Certainly goes up to the max torque recomended for the Axle nuts on a GS no problems, can't see the head bolts being tighter than that (it's 80 odd from memory max)

Dan