don't be like me, shadetree people--get your torque wrench...

[ryan roopnarine]

calibrated, and avoid tragedy.

friday morning/saturday evening, i was reassembling my gm 4l30e transmission. i didn't scrutinize my rebuild manual heavily, and figured that some bolts that i would be putting in would be under ~18lb-ft, and that i would be using the inch-lb wrench. i take pretty good care of the inch-lb wrench, because in my mind it is more delicate than the ft-lb unit. anyways, the inch-lb unit is broken, and i read that the bolt in question is really 18-19lb-ft, and would need to be dealt with the 1/2 inch drive wrench. i will fess up, and say that since the larger wrench is used mostly for lugnuts, it is occasionally left and stored at 100ft-lb. i never have a problem with it clicking off where it is supposed to at that setting. the part in question is about the size and height of a stack of 15-18 dinner plates. the first bolt took a lot of pressure, but eventually clicked off. my friend and I wrote our difficulty off to the fact that a stack of dinnerplates is kind of hard to hold perfectly stationary. perplexed, i tried backing the wrench down to 10ft-lb and putting in the next one.........

grrrr.....the wrench began to move more easily....
expletive

i back the bolt out, and see what appears to be a helicoil come out wrapped around the bolt that goes into the oil slinger of the transmission. i pull it off to see that most of the thread has come out, wholesale, out of the part. the location doesn't lend well to inserts, and this transmission has taken >>>>>4x the time that it should have, so we go down to the autozone and rent one of their torque wrench. a rudimentary test against the new inch-lb unit shows reasonable compliance. installing the rest of the bolts goes with reasonable wrench turning effort, so the gasket should be held in ok. the bolt that pulled the threads out has a little bit of thread to grab on, so we just leave it as tight as we can.

moral...some of you know this already, some of us don't. if youever feel the need to use a torque wrench, you must get it calibrated, or its utility is questionable or non-existent. i won't screw that up again.

[winfred]

i think the cases of those gm trannys are made from old beer cans and lawn chairs, those ****ers suck, i don't even use the new bolts that come with the filter kits as they strip the case out way more then using the old bolts

[ryan roopnarine]

the bolts that i f0xred go into a plate that hold the "pendulum issue" gasket in, i'm hoping that force is distributed well enough by the others. the last time i did the pans on this car, i used half a pack of helicoils and learned what you said the hard way. i kind of wished that i drilled all of the transmission pan bolts out while i had the tranny out and put in coils instead.

[BigKriss]

i jsut leave the torque wrench on setting zero when not in use. i thought when it's stored at a number such as 100 ft/lbs it will go out of sync.

[gale]

i jsut leave the torque wrench on setting zero when not in use. i thought when it's stored at a number such as 100 ft/lbs it will go out of sync.

Correct. Our QA department at work sends out our torque wrenches to be inspected and calibrated quarterly. Prior to using them, set them at the highest setting and click them off 6 times on a bolt in a vise or other convenient bolt that can take that much torque. Store them at zero or the lowest setting when not in use.

[Dave M]

Correct. Our QA department at work sends out our torque wrenches to be inspected and calibrated quarterly. Prior to using them, set them at the highest setting and click them off 6 times on a bolt in a vise or other convenient bolt that can take that much torque. Store them at zero or the lowest setting when not in use.

I wasn't aware of this, until now that is.

Dave

[Ross]

Same here. Mine's always stored at zero but never heard of the other part. What's the reason for clicking it at a high setting?

[BigKriss]

the device clicks when the required torque amount is reached.


Same here. Mine's always stored at zero but never heard of the other part. What's the reason for clicking it at a high setting?

[Ross]

Yes I know about that. What I'm asking is why it is being recommended to operate it at the highest setting six times before using.

[saluki540i]

The reason to operate the torque wrench before use is to "limber" the mechanism inside. I don't know about having to set it to the highest setting to do this - typically just a higher setting than necessary to your application. When the wrenches are calibrated they are placed in a 70 degree F. room for 48 hours to equilibrate, then are checked and adjusted as necessary. My Snap-on wrenches, for example, are checked in both directions because of being reversable. The calibration sticker is typically placed on the handle to give the date done. When finished using they should always be set to 0 - and stored in the house to minimize humidity and hot/cold cycling. I keep all of mine in my Merkur parts storage room. Lastly, per the USAF, if you ain't using the wrench it should be in it's case - less chance of getting banged or worse, dropped.

[Ross]

Thanks Saluki. I'll use your advice.

[saluki540i]

Now if some of you guys were just a little closer to help me get the rear subframe back in my car. It's going to be any day now.