Retorque on the lower intake

[Daggar]

pretend it was laid over the intake

"Ahhhh.... I Seeeee!", said the blind man.

 

[Daggar]

By the way - 'retorque' is actually a bit of a misnomer in my opinion. The problem is friction. If you torque a fastener to 60 ft-lbs. and then try to retorque it -- you have to apply something on the order of 70-80 ft-lbs. of torque to overcome the friction on the threads and get the fastener moving again. So, putting your torque wrench on the fastener with it set to the proper torque and pulling til it 'clicks' (or til the pointer is at the torque for a beam-type) doesn't tell you you're at the proper torque. It only tells you that what ever you had the torque wrench set at isn't high enough to overcome the friction between the threads. The fastener has to be quite loose (well below the rating you were looking for) to move with the wrench set at the desired level. They don't usually loosen that much - although it does happen occasionally.

You usually have only 2 choices. One is to assume everything is ok and not do anything at all. The other is to simply decide you're going to go through the procedure again by slightly backing off each fastener (enough to drop below the friction threshold) one at a time, and then simply pulling back up to the pre-set torque level.

Yep

 

[Michael Yount]

"I see" said the blind man to his little deaf wife; and so she picked up the hammer and saw.

 

[tmoss]

Might be easier to see this one.....

 

[vristang]

By the way - 'retorque' is actually a bit of a misnomer in my opinion. The problem is friction. If you torque a fastener to 60 ft-lbs. and then try to retorque it -- you have to apply something on the order of 70-80 ft-lbs. of torque to overcome the friction on the threads and get the fastener moving again. So, putting your torque wrench on the fastener with it set to the proper torque and pulling til it 'clicks' (or til the pointer is at the torque for a beam-type) doesn't tell you you're at the proper torque. It only tells you that what ever you had the torque wrench set at isn't high enough to overcome the friction between the threads. The fastener has to be quite loose (well below the rating you were looking for) to move with the wrench set at the desired level. They don't usually loosen that much - although it does happen occasionally.

This is dead on.
When I was in Commercial Aircraft Structures production there was a huge effort to stop the mechanics from "double clicking" on every torque. To apply an accurate torque you must turn the wrench in a slow and smooth motion. Once you "click over", any additional force will produce an over-torque.

Also,
How accurate do you guys think your torque wrenches are? My experience is that most wrenches used for automotive purposes are never recalibrated. In aerospace production it MUST be done every several months (part of FAA certification). If your wrench is ten years old, and never been recal'd, it may not be worth using. I am not one to talk though as the one I use for head bolts and lug nuts is a year older than I am (30 this year).

Always store the torque wrench set to zero. Never turn the wrench past zero.

Just some more thoughts for consideration,
jason

 

[Michael Yount]

Yup - I'm actually a fan of beam-type torque wrenches. You can 'see' the torque value coming up - with click-type you get no warning. And there are virtually no calibration issues -- if the pointer is on zero, then it's ready to go. For stuff like lug nuts or the balancer where there's a large range of acceptable torque values -- click type is fine. But for engine internals, etc. -- I use a beam type.

Keep 'em clean and dry; never drop them; never use them as a hammer (seen it done); always set them back to zero if you're not gonna use it in the next 15 minutes; and once every couple of years (home use) or every 3-6 months (commercial use) have the click types calibrated. ESPECIALLY if commercial use means aircraft. I screw up, I lose a wheel/tire - not fun, but usually recoverable. When aircraft mechanics screw up.....

 

[Michael Yount]

The ones that really crack me up are the wheel/tire stores that advertise that they always use torque wrenches on customer's wheels. Can't tell you how many times I've seen the 'kids' doing the work crank the lug nuts on with an air wrench set to who knows how high -- and THEN pick up a torque wrench set to the value for that car (MAYBE) and go around 'clicking'. What a joke.....cracks me up every time.

 

[87gtconv]

They must use a special torque wrench that loosens as well as tightens in one operation. Always wondered how those tire shops get the torque right like that!! Ever try and rotate tires from a tire shop and need a 6 ft extension on the rachet handle????? And they say they have no problems ever taking the wheels off!! And I have never seen them adjust those air guns either.

 

[Michael Yount]

They don't have problems -- they just snap the studs off with the air gun and then you get to buy new studs too!

 

[HISSIN50]

Or when the tire guy is done, he throws the torque wrench down from 3' off the ground onto the concrete.

 

[Michael Yount]

So true...

 

[DMAN302]

Well I was gone for a day and some and I see this thread still lives..though seems to be going in a different direction. Thanks all for the correct torque pattern..but as indicated I did follow the correct pattern the first two times the intake was both torqued and retorqued. The last or third time I was only checking and went out of pattern tightening up the outside corners of the intake. I know the engine will be fine..I was just asking a question out of curiosity more than anything. Thank you all very much for the information...especially the info by Mike on the turning the torque wrench back to zero after use..I had not done that previously, now it will be the way it's done. Thanks again guys I appreciate your time.

 

[HISSIN50]

FWIW, what kind of places do you folks take your clicker torque wrenches to when you want to get them cal'd? I have always been too lazy to get it done. Ball park cost? Maybe I should call a local place that has theirs cal'd and when they send a batch off for their periodical calibration, they could toss mine in the batch......

 

[Michael Yount]

If you've been storing it for long periods of time without it being turned back to zero (by the way - it says to do that in the instruction manual ) you might want to have it recalibrated.

See what happens when you leave for a day?

 

[Michael Yount]

Check with a local mechanic to see where they have theirs done -- I've got a place here in Knoxville - not that that does you guys much good.

 

[HISSIN50]

Thanks Michael.