Torque wrench - how necessary?

[Tom '74 911]

Experts and professional mechanics - please don't laugh at this question!

I'm just digging into my suspension, setting up my ride height, replacing bushings etc... and was wondering just how important a torque wrench is when I go to put this all back together. I think if I was rebuilding my engine - which would be beyond my current capabilities anyway, I would, without question need one.

Also, if I did have a torque wrench, where does one find the proper torque values for all the necessary bolts? Is this where a factory workshop manual comes in handy?

Thanks,
Tom

[GIBSON]

Tom, you'll find a few different opinions around here on this one.
Some of the pros here have worked on these cars so long and are so familiar with the "feel" they are looking for in a fastener that they tend to not use the torque wrench as much. They just feel they get a good result from their own experience. Others feel that torque wrenches are essential.
My opinion is that if you are not familiar with what fastener should get what torque and how that feels, you might consider a good torque wrench and use it. Sears used to warantee their torque wrenches like other tools, now they don't. I've opted to spend the extra bucks and get snap-on. I usually hit the driver up for wrenches that have been traded in on the new electronic types the pros use and pick up their old click-type wrenches right after they come back from calibration. I think most good snap-on guys send out their trade-ins for re-calibration after they are traded in. The last one I got I just paid the re-calibration costs and had a great torque wrench.
Torque values can be hard to find sometimes, the factory manuals give many of them but they can be scattered all over the manuals. Wayne gives some in his book I believe, just post your question here-you'll get a quick answer.
Edit: regarding suspension torque figures, some of them are so high that you'd need a 1/2 in torque wrench for sure and even then some suspension bolts get torqued really high (axle nuts, the eccentric adjuster on the trailing arms etc.). However, these are important fasteners and you want to be sure they are the proper torque.

[jester911]

Well personally I think it is even more important for a torque wrench on suspension parts than engine as far as safety.

If something comes apart at speed in the suspension you may not have a chance to change your mind later.

As far as the torque values, you can get a bentley manual,
101 projects, and really most any number you are looking for can be found either in a search here or just post the question.

[randywebb]

agree - absolutely
A blown engine is usually just $$. A suspension problem can be your life, or a life spent trying to turbocharge your sheel-chair (in between bouts of pain drugs). And surgery is not cheap. 'nuff said?

For info on what brands to buy put both words into the search box

The only item I would buy from Griot's Garage is their torque wrench - it has a calibration certificate and they will re-cal for free (you ship it to them). THey fit great into the FedEx triangular boxes BTW.

The spring click type ones do require re-cal.s periodically.

The cheapest are the indicating bar ones if you want to save $$. They are fairly accurate. You needa 1/2" drive one for the suspension.

You can always save $$ by borrowing from a friend or club member. Ask them when the cal. was checked....

[Tom '74 911]

I kind of knew the answer before I asked. I just needed some reinforcement before throwing down big bucks. Sounds like the jury's in and I've got one on my list to buy asap.
Thanks,
Tom

[imcarthur]

You'll find - as I am - that you should have two. A 50-250 (a big long mama) & a 25-50 (the one I don't have & need). I also bought a low torque ft-in thing that only goes up to about 24 ft-lbs but so far it's only been good for valve covers.

The 'indicating bar ones' are next to useless imho.

Ian

[ChrisBennet]

Just a few thoughts on torque wrenches.
- You definately need them on suspension.
- Torque wrenches come in ranges. The one you use for the suspension will not go low enough for most engine work. Most aren't as accurate near the end of their range.
- Torque is a very crude way of estimating bolt stretch. People tend to worry how accurate the torque wrench is and ignore thee conditions (lubed/dry/new fastener/etc) under which the torque specified.
- I use a Sears clcker torque wrench for suspension and wheels. It's not so dear that I'll feel really bad if it gets lost or left on the pit wall. The plastic grip is nice because it saves the bodywork in the event of a slip while torquing lug nuts.
- Clicker types are just not very accurate. (In general.)
- I believe Griots will check your Griots torque wrench for free. I don't think their catalog says anything about recalibrating it for free.
- If you're on a budget, the "cheap" beam style torque wrenches are more accurate than wrenches 2-3 times the price.
- If you're not on a tight budget or you'll be using the wrench a lot, SnapOn sells some nice electronic ones now that won't break the bank.
-Chris

[randywebb]

"- I believe Griots will check your Griots torque wrench for free. I don't think their catalog says anything about recalibrating it for free."

- Yeh - I dunno which. BUT BUT -- if it is not very accurate, just tell them to send a new one out under their "We charge so much we guarantee everything for life" guarantee. The torque wrench is the only thing they sell that is worth in IMHO...

Good summary Chris. Sears has a digital indicator one also - no idea how accurate these are...

In some old threads I recommeneded that people find out what their local aerospace firm uses (if you are on the Left Coast then you have one not far away). I get less impressed with Snap On as time goes on...

[steve911]

Originally posted by GIBSON
Sears used to warantee their torque wrenches like other tools, now they don't.

Bruce--
I have to disagree with your statement above, based upon fairly recent experience (last 3-4 months). I brought my 25+ year old beam-type Craftsman torque wrench in to my local Sears (Concord, CA) and walked out with a brand-new, identical model # one. No questions asked. It may be that they do not warrantee their electronic or clicker-type torque wrenches, but the beam-type are still covered under the Craftsman lifetime warranty.

[ChrisBennet]

Randy, I have a SnapOn TECH2FR100 which has worked well for me. It vibrates when you reach the torque setting and it records the actual torque applied. A touch of a button and you're working in Newton Meters, Inch #'s, foot #'s, etc. Easy to read without glasses too. Got mine on E-Bay.

Steve, Sears hasn't warranteed their clicker wrenches in some time, maybe ever. A clicker degrades in accuracy over time but the beam type can be pretty much run over and bent back into shape and keep it's accuracy.

-Chris

[TerryH]

I highly recommend the clicker type. So easy to use and so much more versatile. You can't always see the dial as you reach under you car to torque a bolt, but you always feel that click. I agree the dial type can be more accurate, but I would still buy a "clicker" as my only torque wrench if I could just have one.

[Tom '74 911]

Thanks again for everyone's usefull thoughts and comments.
Tom

[safe]

I'm doing some suspention work this winter (if I can find someone who can sell me some Sander bars...).
What torque range do I need to cover?

[imcarthur]

Most torques for rear suspension are 60-100. But the torsion bar cover bolts are 34 & on the high side is the height eccentric & clamp on the springplate at 181. And if you don't do that one up tight enough, you'll find out on your first drive. (All in ft-lbs)

Ian

[safe]

Allright, I need a bigger torque wrench...

[Wavey]

Big enough for you?

[safe]

That can also be used as a breakerbar

Shiny torsionbar covers

[AtomicDog]

Hey Wavey,

Is that a 0-450, or a 0-600? I used to twirl a 0-600 to help "focus" my Navy students when teaching reactor plant valve operations. Worked well.

Tom '74 911,

For the basics in any torquing job -

Select the wrench for which your desired torque falls within 20-90% of the wrench's scale.

"Excercise" the wrench five or six times by cycling it to 75% or so of its full range prior to use. I do this with my bench vise (smooth jaws).

For big torque, tighten in increments. I.E.: to go to 150 ft lbf, torque all fasteners to 80, then 130, then 150, then go back and do 150 on all fasteners again.

I would suggest having three wrenches - 0-100 ft lbf, 0-250 ft lbf, and 0-300 IN lbf. The little guy should be a clicker, but for the big ones, the dials are much more accurate.

Both the Snap-on and CDI wrenches are used in the nuclear industry, and should be treated like you treat your dial indicators and micrometers. Cared for, they will last you at least one lifetime, possibly more.

As a note, Snap-on and CDI wrenches (can) come with an indicator light. When you get to your preset torque, contacts in the dial assembly light up a flashlight bulb on top of the wrench. You can see the light, even when you can't see the dial, particularly in a shadowy engine compartment.

Your experience with the torque wrench will build the feel necessary for "calibrated shoulder" operations where the wrench won't fit.

Good luck, hope this helps you.

Chris

[Wavey]

Originally posted by AtomicDog
Hey Wavey, Is that a 0-450, or a 0-600? I used to twirl a 0-600 to help "focus" my Navy students when teaching reactor plant valve operations. Worked well. Chris

It's a 50-300 Harbor Freight cheapie. Mainly bought it to do the rear axle nuts, which call for 339 ft-lb on the Carrera. I set it to 300 and give it a little more, figure that's closer than a complete guess with a breaker bar. I have a buddy who runs a Ford dealership shop so we're going to compare it to his Snap-On.

Originally posted by AtomicDog
Select the wrench for which your desired torque falls within 20-90% of the wrench's scale.

"Excercise" the wrench five or six times by cycling it to 75% or so of its full range prior to use. I do this with my bench vise (smooth jaws).

For big torque, tighten in increments. I.E.: to go to 150 ft lbf, torque all fasteners to 80, then 130, then 150, then go back and do 150 on all fasteners again.

I would suggest having three wrenches - 0-100 ft lbf, 0-250 ft lbf, and 0-300 IN lbf. The little guy should be a clicker, but for the big ones, the dials are much more accurate.

Chris

Excellent advice! I have a 1/2" drive 0-150 clicker, a 3/8" drive 0-100 clicker, and a 3/8" drive in Inch-Pounds, beam-type, that's really nice for the smaller stuff. Plus the big 3/4" drive above.

[Navaros911]

Tom,

For my suspension work I used two ranges: a 20-120 Nm and a 50-250Nm one. This would approximately be 15-90 Ft.Lbs and 35-185 Ft.Lbs. Both were of the click type... the bigger one was just calibrated a month or so ago (my uncle did this, he works in the airline maintenance industry... these guys know a thing or two about torque wrenches).

You will want to make sure that you tighten the trailing arms enough... and that's a b!tch you need a long one for that. Not to mention the springplates.

Avoid getting one big one that covers everything... as mentioned they are not that accurate at their extremes. Also a smaller one is handy to get in tight spots and I will opt for the smallest one I have when not over the 80% range.

- Michiel