Torque Wrench Really Needed?

[Sniper82]

Doing a plug job on a car and am wondering is a torque wrench really needed? Also why type would I need? The plugs I got came with gaskets could someone tell me which way they need to go on(if it matters) or if they even need to be used?

The gaskets look different on each side.

 

[Gillbot]

It's advised but many people have never used one. I'm sure their car is still running ok. That being said though, I use one to be sure and safe.

 

[nakedfrog]

I've always just hand-tightened them, then tightened them just a bit more with the socket.

 

[fstime]

I would get one.

 

[RayH]

The gaskets are usually crush gaskets and you should use them. I don't think gasket direction makes a difference. Finger tightening the plugs without a wrench will get the gaskets touching the base and another half turn with a wrench is usually enough to crush and seal.

Plugs are low torque and require a low range torque wrench that doesn't have much other use other than possibly valve cover bolts so it's questionable whether it's worth getting one just for the plugs.

 

[flamingelephant]

if you have an aluminum head on your car then its a good idea if you've never done it before. A torque wrench can be picked up for 20 bucks on sale. Don't forget to use anti-seize on the threads as well

 

[HannibalX]

Certain things must be torqued to a certain spec or you are asking for trouble - like lug nuts.

I have never used one when installing spark plugs. Make sure you put some anti-seize compound on the threads of the plugs and some dielectric grease on the top end where the boot connects to the plug.

 

[Toastedlightly]

I believe it goes something like...
For gasket plugs, hand tighten, then turn pi/2 radians
For tapered plugs, hand tighten, then turn pi/4 radians

 

[DeviousTrap]

Since we're on the same topic, a friend is asking for help to change the throttle body in his Saab. I pulled up instructions online and it calls for torquing the bolts to 7.4ft-lbs, but I can't seem to find any affordable torque wrench for that measures anything <10ft-lbs. Is 7.4 a relatively small amount of torque?

 

[LennyZ]

Use an inch pound wrench.
12 in/lbs = 1ft lb

 

[Pacfanweb]

Originally posted by: DeviousTrap
Since we're on the same topic, a friend is asking for help to change the throttle body in his Saab. I pulled up instructions online and it calls for torquing the bolts to 7.4ft-lbs, but I can't seem to find any affordable torque wrench for that measures anything <10ft-lbs. Is 7.4 a relatively small amount of torque?

Just hand tighten it. Nobody uses a torque wrench to tighten that sort of stuff, including the factory.

Same goes for plugs.

 

[Zenmervolt]

Originally posted by: Pale Rider
Certain things must be torqued to a certain spec or you are asking for trouble - like lug nuts.

I have never used one when installing spark plugs. Make sure you put some anti-seize compound on the threads of the plugs and some dielectric grease on the top end where the boot connects to the plug.

You use a torque wrench for lug nuts? Just tighten in the right pattern with an 18" breaker bar and when you've taken up the slack in the metal, you're good.

Torque wrenches are really for things like head bolts where the wrong torque can apply a twist and affect the sealing of a gasket. I've always just turned things until the feel like they're properly tight. You can feel when something is too tight.

A warning about anti-seize compound though, you should be sure to only get it on the threads and then only very, very lightly. If you get it on the tip of the plug or into the combustion chamber, it's not good.

ZV

 

[Sniper82]

Originally posted by: Zenmervolt

Originally posted by: Pale Rider
Certain things must be torqued to a certain spec or you are asking for trouble - like lug nuts.

I have never used one when installing spark plugs. Make sure you put some anti-seize compound on the threads of the plugs and some dielectric grease on the top end where the boot connects to the plug.

You use a torque wrench for lug nuts? Just tighten in the right pattern with an 18" breaker bar and when you've taken up the slack in the metal, you're good.

Torque wrenches are really for things like head bolts where the wrong torque can apply a twist and affect the sealing of a gasket. I've always just turned things until the feel like they're properly tight. You can feel when something is too tight.

A warning about anti-seize compound though, you should be sure to only get it on the threads and then only very, very lightly. If you get it on the tip of the plug or into the combustion chamber, it's not good.

ZV

I bought some compound for the plugs since it was only $1 but is it really needed? I didn't use it on a plug change a few months back on another car. Which I didn't use a torque wrench for it either and its fine. I was just curious if a torque wrench was important. I tight till its snug but no where near where I think it might strip the threads.

 

[Killrose]

Origional OP: Use the gaskts. I would not worry about thier orientation. A tourqe wrench is not needed unless you are unsure as to how tight is too tight. A crush/gaskt/ washer will usually allow another 1/8-1/4 turn after initial tightening. A little bit of grease on the threads is a good thing, especially if when removing the old plugs they will not turn out by hand.

So: Put your crush washers on, a light smear of nearly any grease on the first 3 or 4 threads or none at all. Screw the plugs in first by hand to make sure you are not cross threaded, then with a wrench untill you feel the plug is threaded fully and resisting further turning. Now give it another 1/8-1/4 turn to fully seat the "crush" washer. Applied pressure should be "firm" and you should not feel your self "struggling" to apply pressure.

 

[SparkyJJO]

Originally posted by: Zenmervolt

Originally posted by: Pale Rider
Certain things must be torqued to a certain spec or you are asking for trouble - like lug nuts.

I have never used one when installing spark plugs. Make sure you put some anti-seize compound on the threads of the plugs and some dielectric grease on the top end where the boot connects to the plug.

You use a torque wrench for lug nuts? Just tighten in the right pattern with an 18" breaker bar and when you've taken up the slack in the metal, you're good.

Torque wrenches are really for things like head bolts where the wrong torque can apply a twist and affect the sealing of a gasket. I've always just turned things until the feel like they're properly tight. You can feel when something is too tight.

A warning about anti-seize compound though, you should be sure to only get it on the threads and then only very, very lightly. If you get it on the tip of the plug or into the combustion chamber, it's not good.

ZV

I heard that if you don't use a torque wrench on the lug nuts you get different amounts of torque on them (say 105, 110, 93, 122, and 114 ft lbs) and that uneven pressure can warp your rotors. This true or not?

All I've used previously was my tire iron, but my rotors were already warped so I didn't care much if it was true or not But now with my new car and new rotors I want to be sure I don't screw anything up.

 

[Jeff7181]

Originally posted by: flamingelephant
if you have an aluminum head on your car then its a good idea if you've never done it before. A torque wrench can be picked up for 20 bucks on sale. Don't forget to use anti-seize on the threads as well

Be very careful with the anti-seize... you don't want any in the combustion chamber as it will ruin oxygen sensors.

 

[Pacfanweb]

Originally posted by: SparkyJJOI heard that if you don't use a torque wrench on the lug nuts you get different amounts of torque on them (say 105, 110, 93, 122, and 114 ft lbs) and that uneven pressure can warp your rotors. This true or not?

All I've used previously was my tire iron, but my rotors were already warped so I didn't care much if it was true or not But now with my new car and new rotors I want to be sure I don't screw anything up.

Don't sweat it. A rotor would have to be ridiculously weak for a few lbs of torque difference to warp it.

I've installed literally thousands of tires....and nearly all of them with an impact gun. Never warped a rotor yet.

Except for one....my old Trans Am. Temporarily traded wheels with a friend and his were mags. I tightened them down in an circular pattern (hey, I was 18) and drove it around the block....about shook me out of the seat first time I hit the brakes.
These were the old style that had the hub and rotor made together. So I get back to the shop I worked at, told one of the older guys what was wrong...he looked at the mag wheels, told me to remove them, then tighten them incrementally in a star pattern....the rotors were perfect then....didn't even have to machine them.
So that was caused by the wheels, not by my using the impact gun, since I used it the second time, too.

Warpage on today's floating rotors caused by not torquing is almost non-existant. It's simply something that used to happen years ago and is still taught today.

 

[BW86]

Originally posted by: nakedfrog
I've always just hand-tightened them, then tightened them just a bit more with the socket.

qft

 

[Uhtrinity]

Originally posted by: Sniper82
Doing a plug job on a car and am wondering is a torque wrench really needed? Also why type would I need? The plugs I got came with gaskets could someone tell me which way they need to go on(if it matters) or if they even need to be used?

The gaskets look different on each side.

A torque wrench is absolutely required if your car has indexed plugs, which fortunately, few have.

 

[Killrose]

Originally posted by: SparkyJJO

I heard that if you don't use a torque wrench on the lug nuts you get different amounts of torque on them (say 105, 110, 93, 122, and 114 ft lbs) and that uneven pressure can warp your rotors. This true or not?

All I've used previously was my tire iron, but my rotors were already warped so I didn't care much if it was true or not But now with my new car and new rotors I want to be sure I don't screw anything up.

I worked in a Honda / Toyota dealership for 13years from the late 70's to 1990 both as a mechanic and in my final years as the service manager, and I can tell you on Jap cars of that era, you had better use a torque wrench or dam well be sure your air tools were turned down to put you within torque specs. We got all kinds of warpped rotor jobs due to tire shops with children behind the tourque wrench.

I'd say a low of 93ft lbs and a high of 122ft lbs could be trouble. Within 15ft lbs of each other would be OK IMHO

 

[Pacfanweb]

Originally posted by: Killrose

Originally posted by: SparkyJJO

I heard that if you don't use a torque wrench on the lug nuts you get different amounts of torque on them (say 105, 110, 93, 122, and 114 ft lbs) and that uneven pressure can warp your rotors. This true or not?

All I've used previously was my tire iron, but my rotors were already warped so I didn't care much if it was true or not But now with my new car and new rotors I want to be sure I don't screw anything up.

I worked in a Honda / Toyota dealership for 13years from the late 70's to 1990 both as a mechanic and in my final years as the service manager, and I can tell you on Jap cars of that era, you had better use a torque wrench or dam well be sure your air tools were turned down to put you within torque specs. We got all kinds of warpped rotor jobs due to tire shops with children behind the tourque wrench.

I'd say a low of 93ft lbs and a high of 122ft lbs could be trouble. Within 15ft lbs of each other would be OK IMHO

Would not most of those cars in the 70's to 1990 have had integral hub/rotor assemblies, and not floating rotors?
If so, then yeah, those are definitely more prone to warping.

 

[alkemyst]

box of plugs should say the tightening specs for without a torque wrench...or the shop manual.

biggest thing is to know they don't have to be uber tight and if you have an aluminum head you better use anti seize.

 

[alkemyst]

Originally posted by: Pacfanweb

Originally posted by: DeviousTrap
Since we're on the same topic, a friend is asking for help to change the throttle body in his Saab. I pulled up instructions online and it calls for torquing the bolts to 7.4ft-lbs, but I can't seem to find any affordable torque wrench for that measures anything <10ft-lbs. Is 7.4 a relatively small amount of torque?

Just hand tighten it. Nobody uses a torque wrench to tighten that sort of stuff, including the factory.

Same goes for plugs.

Most of the guns and robotics are pre-set for the torque they tighten too on an assembly line.

 

[alkemyst]

Originally posted by: Pacfanweb
something about impact guns and not warping rotors....

Being you worked in a shop, chances are you didn't warp a rotor because you weren't around on the car when it happened.

Impact guns have torque clutches usually in a wheel shop, real wheel shops do the final torques by hand though. To easy to miss with a gun and screw up a wheel or even with a clutch to overtighten.

With out a torque setting no one is going to be able to tell 75 ft/lbs vs 100 ft/lbs

I have had two lug studs that had to be totally replaced due to grease monkeys thinking they know about cars.

I absolutely avoid these kinds of shops when possible.

 

[Zenmervolt]

Originally posted by: Killrose

Originally posted by: SparkyJJO

I heard that if you don't use a torque wrench on the lug nuts you get different amounts of torque on them (say 105, 110, 93, 122, and 114 ft lbs) and that uneven pressure can warp your rotors. This true or not?

All I've used previously was my tire iron, but my rotors were already warped so I didn't care much if it was true or not But now with my new car and new rotors I want to be sure I don't screw anything up.

I worked in a Honda / Toyota dealership for 13years from the late 70's to 1990 both as a mechanic and in my final years as the service manager, and I can tell you on Jap cars of that era, you had better use a torque wrench or dam well be sure your air tools were turned down to put you within torque specs. We got all kinds of warpped rotor jobs due to tire shops with children behind the tourque wrench.

I'd say a low of 93ft lbs and a high of 122ft lbs could be trouble. Within 15ft lbs of each other would be OK IMHO

Bah. I had the wheels on and off of my old 1988 Accord dozens of times. Never had problems with rotors warping and I never used anything more precise than "damn tight" with the lug wrench that was included in the spare tire kit. You'd have to be a damn idiot to put too much torque on a lug nut without an air gun.

ZV