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Triumph TR6 - torque wrench question

What would you guys with more experience recommend for a 3/8 " drive? The older torque wrenches I am familiar with are now referred to as "box torque" wrenches--they have the half circle scale with the arrow. The "more modern" ones have a micrometer setting of some sort; these cost a lot more and I have never used one.

I guess if I'm going to take things on the 71 TR6 apart and hope to put them back together correctly, a torque wrench will be a necessity. For instance, I had a little oil seeping out from one of the bolts on the valve cover, and I do not want to overtighten it-I may have to take it off, replace the washers, gasket, etc., and I want to put it back correctly.

Thanks, John, fka JohnB from SoFl.
JL Bryan

Hey John,

I see the Sheriff hasn't caught up to you yet.

Go with the 'clicker' type. THAT way you don't have to watch the dial when you're in some impossible position.

The good news is that a decent quality 3/8" clicker isn't expensive.

Besides, never, ever, ever scrimp on your tools my friend. You will have them for the rest of your life.

Jim
Jim Deatsch

Aren't torque specs useless when the fastener being torqued is lubricated with something like anti-seize compound? If you torque to "dry" spec with a lubed fastener, don't you run the risk of over-torquing it and inviting failure?

Rick O.
Rick Orthen

Actually,

If you refer to a 'torque values' chart as published by most fastener manufacturers you'll see that they list dry and lubricated settings.

Jim
Jim Deatsch

Jim--Is there a thumb rule to convert dry to lubed specs (something like 90% of the dry spec)?

Rick O.
Rick Orthen

Hmmm, not that I know of Rick.

I'm sure there are some fastener gurus that would know that though.

It WOULD be interesting to have that conversion.

Jim
Jim Deatsch

Interesting - the ARP head studs listed a torque for "oil" and a somewhat lower one for the high moly slick-as-snot lube that was included. I've always heard to never dry torque, though.

Brent

Brent B

I agree with you Brent.

Why WOULD you not lube a fastener unless it was verboten.

Jim
Jim Deatsch

Does thirty years count for something ?? I've always cleaned the threads, lubed w/ engine oil, and torqued to the specified value. Right or wrong, there's never been a failure, so it must be 'right enough'. And yes, never scrimp on tools. Peter
Peter Gooch

Another important thing with torque wrenches is to get their accuracy checked every now and again, cheap ones left unused for several years can be miles out
Ron
R. Algie

It does indeed Peter. I ALWAYS lube (with motor oil) ANY fastener (Unless otherwise directed <G>).

"There's no substitute for experience".

Jim
Jim Deatsch

I agree with lubing prior to inserting the bolts.

One easy way to check the calibration of a torque wrench is to use two of them. Connect them together using a 12-point socket of the correct size to fit the shaft, set them for the same torque value, and see how closely they click together. You can also do this with one clike-type and one beam-type, by watching the beam pointer and noting when the clicker sounds off. (Of course, you can also use a bench-mounted bolt and weights or a Skimore-Willham devise if you have one).
R.C. Blair

you a SMART feller Bob.

I never thought of that one. Thanks a BUNCH.

Jim (off to calibrate things now)
Jim Deatsch

John
After every use of your fancy, new, expensive torque wrench, remember to release all tension on the torque wrench (reset it back past zero). Accuracy will be maintained longer.
Rick c
Rick Crawford

Rule of thumb for wet verses dry is 68% by millwright manual. That would give a valve cover a reading of 10.2 inch/lb rather than 15 on GM.

Dealing with new bolts in a proper thread chased not retapped item like a block I tend to use dry. For valve covers/oil pans I always wash the bolts and blow out the holes. Makes quite a difference torquing.

Torque wrenches come in all sizes for the job intended mine are 1/2 3/8/ 1/2 is in foot lb 3/8 inch lbs. both click types about $250 Canadian for both SK not the best but I don't use every day. You will need both. Still have my 1/2 inch Mac bar type 1/2 circle with arrow 30 years old probably. Accurate but hard to use in some situations.

Always sneak up on the end value in increments work the wrench with a smooth slow swing. And one trick with the bar type is bring up to final torque and hold. In most cases it will drop so bring up again and you have a good reading. Many older mechanics/engine builders I know will only use the bar type doing head bolts?




Bill Brayford

I know my grandfather never used a clicker type on engines or transmissions. I have carried that over myself. When it comes time do any engine stuff out of the car and on the stand, I go into retro-grouch mode and grab a trusty old beam unit. In the car, it depends on what it is/where it is on deciding to use a clicker or beam unit. Most anything else is one of the clickers.
SteveP

Jim - I can't be too smart - I missspelled "device"

One other thing - torque wrenches are only "supposed" to be used to tighten, but I frequently will use the beam style to take apart old things that I don't have any specifications for and need to get an idea of the torque setting they were at. The reading at which the bolt moves (overcomes stiction) is meaningless, but if you then retighten to the original location of the bolt flats, it does give some indication of the torque once used. Of course, if no information is available at all, use the charts for bolt material, size and TPI and anchor material.

Also, as Rick pointed out, it is indeed important to relieve the stress in the cliker types when done by returning the setting to "0" or "Stop" (some wrenches don't go to "0")
R.C. Blair

This thread was discussed between 13/10/2003 and 15/10/2003

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