Is your torque wrench calibrated

[dbeardslee]

Some months ago I happened on this website that had some excellent instructions for checking and calibrating your torque wrench at home. While this site gives you the info you need to obtain a calibration ratio, you can also use the info to set your torque wrench, if it is adjustable.

I had a torque wrench from Sears that was DOA. It wouldn't click at all. I took it apart, fixed the problem, and recalibrated using this info. It works great. Here's the link:

Torque Wrench Calibration

[Dragon Tamer]

My BIL uses the original rednek fitzall torque wrench, no calibration needed!
You just use the biggest wrench you can lift, tighten whatever you are working on until it starts to strip out. Then back it off one quarter turn. He says it will work on anything!!!

[skids]

That is exactly how I bent the valves in the beast after doing a cam chain adjustment once... Hey, are you callin' me a redneck???

Originally posted by Dragon Tamer
My BIL uses the original rednek fitzall torque wrench, no calibration needed!
You just use the biggest wrench you can lift, tighten whatever you are working on until it starts to strip out. Then back it off one quarter turn. He says it will work on anything!!!

[TADracer]

Read dbeardslee's link in detail ..... Had trouble making it through the first two paragraphs (take no offense please).

Now many years ago I was told by a rather well respected racer that perhaps except for things like space travel, the need for a torque wrench to be totally accurate is not all that necessary.

Within 10% is OK and most torque wrenches go out of calibration on the light side with use. The idea is to provide the proper amount of stretch in the fastener and to evenly fasten the part over its entire surface. Having the threads (both male and female) properly cleaned and properly lubricated before torqueing can provide much more than 10% variance in the achieved torque value.

Think about it and consider that if your wrench is 10% off then at 10 lbs/ft you are within 1 lb/ft and at 75 lbs/ft you are still within only 7.5 lbs/ft (7.5 lbs/ft is barely more than finger tight). Lets say you are torqueing lug nuts to 150 lbs/ft, still the error at 10% is only 15 lbs/ft, which can be achieved with a screwdriver. It is much more important that, 1. some sort of torque wrench is actually used for critical fasteners and 2. that the torque pattern, if any, is followed (such as in a cylinder head) to prevent warping.

Having said all this, I believe it is very important that you use a torque wrench, calibrated or not, on all fasteners into aluminum (such as most of ours). It will prevent you stripping out those delicate aluminum threads.

One more thing. On any part that sees high heat, such as a cylinder head, you need to re-torque your fasteners after the motor has been thouroughly heated and cooled a couple of times. The hot/cold cycle may actually looseten fasteners (without any wrench). And, if you have a micrometer torque wrench (the click type) is is very important you looseten the adjustment to zero after you finish using the tool to relieve pressure on the spring which is the part that provides the calibration. OK, that was two.

Just my $0.02

[dbeardslee]

TADracer:

No offense taken.

The gist of the article is that you measure from the center of your square drive (where the sockets snap on) to a distance one foot down the handle (on foot pound wrenches) and put a mark at that point. Clamp your torque wrench's square drive in a vise with the handle suspended horizontally. Take the amount of weight that the torque wrench is set to (I use 10 pounds with the wrench set to ten foot pounds) suspend it from a thin piece of wire and place it very gently where you made the mark. If the wrench clicks when the weight is closer to the square drive it is set to heavy, and if it clicks farther away from the mark it is set light. On mine I use the adjusting nut to set it so it clicks right on the mark - calibrated.

I originally started down this path with a torque wrench that wasn't assembled correctly (Sears clicker type). I had bought the thing and it sat in my tool box for a while before I tried to use it, at which time I discovered two things - first that the wrench wasn't clicking at all, and second that Sear's lifetime warranty on hand tools didn't apply to torque wrenches!

Anyway, after I took the thing apart and reassembled it correctly, I had to calibrate it, and couldn't see paying someone to do it. Having found how simple it is I now check my wrenches regularly. I think it is important, particularly on a new tool, if only to see what you've got.

I agree that most of the time if you're close in your torque setting it's good enough, but I figure if I'm going to take the time to torque bolts I might as well make sure I'm torqueing them to spec. I'm probably a little anal that way

[Dragon Tamer]

Hey Skids,
Didn't intend to call anyone names (except for the BIL!). Actually I cannot crow too much as I have inadvertantly used his method a couple of times myself (BTBT). Yesterday was a prime example, I was going through the spring routine (fluids, oil change etc) and stripped out the lock screw for the cam chain tensioner. This caused me to spit out a seven syllable word that the SWMBO did not even suspect that I knew. Not really a serious problem, just tapped it out to a size larger and now it will be a little harder for me to ham fist it but it did delay my much anticipated ride for an hour or so !@#$%^&*!
SWMBO says that I should quit using such words but I explained to her that if do that it would cut my vocabulary in half so I have to delay that particular resolution until I learn some other large words that I can use in public. Maybe by next New Years?

[TADracer]

Originally posted by dbeardslee
TADracer:

No offense taken.

Thanks, cause I really am such a sweet guy though I do get a bit uptight sometimes and yell and start using seven syllable words every now and then but when I catch myself doing that I just fly off the handle for awhile but then I just loosen up a bit ..... relax.......take it slow......and then re-torque myself into the sweet guy I really am again.

Thats how I know you have to re-torque hot parts.

[dbeardslee]

TADracer:

Funny you should mention hot parts and in particular cylinder heads. I bought my bike last August, and it hadn't run in three years. Went through the carbs, coils, electric system, etc., etc. and finally got it running really good. Replaced a leaking valve cover gasket and cam chain tensioner gasket (new RTV for the plug) which allowed me to see that I also have a leak in the head gasket!

I looked at Bike Bandit (what an appropriate name) and they want $103.81 for the head gasket (oem) and another $25 for the valve cover gasket!!! I wound up ordering a gasket set from Partsnmore with these two gaskets a bunch of other ones for $77.

Now here's a question for you. As I look at it, the cylinder gasket (between the cases and the cylinders) does not appear to be leaking but I'm a little concerned that when I pull the head off it may disturb that gasket. How much trouble is it to pull the cylinders off and then refit? Any special tools required? I don't want to do it if it isn't going to be a problem, but I'd hate to replace the head gasket and then have to go back in to fix the one below it.

I'm going to follow your advice on retorqueing the head after it heats and cools. Nice tip.

By the by, I just checked your member profile and saw that you were in the 101st. I was in the 2nd of the 75th. Airborne all the way. HUAH!

[Ken Talbot]

Originally posted by dbeardslee
... but I'm a little concerned that when I pull the head off it may disturb that gasket.

There's not very much chance of that. Usually, guys get the head off okay, then come back here looking for answers on how to dislodge the cylinders without having to use explosives. Lifting the cylinders is usually a difficult job, one that has you speaking in tongues by the time you're done.

BTDT...

[dbeardslee]

Ken,

Thanks for the reply - my peace-of-mind index is certainly improved. On a related issue, can the valve clearances be set while the head is off or does it need to be on the bike? I'm thinking it would be easier to do on a bench. I must be getting older 'cause everytime I see an opportunity to keep from bending over I take advantage of it

[DiverRay]

Valve clearance can and SHOULD be set on the bench. It may be a little hard to turn the cams, but just install one cam, adjust, remove cam and install second cam, adjust. Don't forget to have the head up on some blocks, so the valves will not hit the work bench!

[dbeardslee]

Way cool. Thanks Ray.

[planedick]

Like Ray said...

Just remember ONE CAM AT A TIME. I didn't know this and in the process of turning the cams I bent a valve. You can't do it with both cams on the head.

[prometheus578]

T.C. often tells the same tale, PlaneDick.
One cam installed at a time, like they all said, or when turning, say the intake cam, you'll send an intake valve into an already open exhaust valve.

[dbeardslee]

Plane and Prom:

Thanks for the great advice. When I remove the head I want to get as much as of the carbon build-up off as I can without completely dissassembling the head. Any good tricks for this operation?

Prometheus - noticed your from Olympia. I spent a couple years on the big federal reservation 10 miles to your northeast. Beautiful country, and Olympia is a real jewel.

DB