belt tensioner assembly

floridafitz

Original poster
Member
Jan 2, 2012
151
Winter Springs FL
Ordered a new belt tensioner assembly and wondered if it's okay to install without a torque wrench by just snugging the single 15mm mounting bolt with a long breaker bar or my longest rachet. Hate to admit I don't have a torque wrench.
 

CaptainXL

Member
Dec 4, 2011
2,445
floridafitz said:
Ordered a new belt tensioner assembly and wondered if it's okay to install without a torque wrench by just snugging the single 15mm mounting bolt with a long breaker bar or my longest rachet. Hate to admit I don't have a torque wrench.

I would torque it. Rent one. Every other search comes up with sheared bolt.

Its good practice to torque most things vital under the hood. Like the belt tensioner and power steering pump. Basically anything that moves a lot.
 

The_Roadie

Lifetime VIP Donor
Member
Nov 19, 2011
9,957
Portland, OR
floridafitz said:
... snugging the single 15mm mounting bolt with a long breaker bar or my longest rachet.
That would be huge overkill and risky because the spec for that bolt is only 37 ft-lbs.
Hate to admit I don't have a torque wrench.
I'll notify Harbor Freight there's an underserved neighborhood they should open a store in. :wink:
 

floridafitz

Original poster
Member
Jan 2, 2012
151
Winter Springs FL
Actually have a HF nearby so guess I'm without excuse. Assume any of their torque wrenches will do. Thanks for the heads up....may have avoided a shear since I've no idea what 37 lbs/ft feels like.
 

CaptainXL

Member
Dec 4, 2011
2,445
floridafitz said:
Assume any of their torque wrenches will do.

Don't assume. If you use too big of a wrench then you can accidentally torque it too much. Too much leverage as Bill said is not a good thing. Long extensions are also a no no cause they can alter the torque as it is a function of handle length.

You need to reach down in there, get on top of it and torque it properly.

Get this one: http://www.harborfreight.com/1-2-half-inch-drive-click-type-torque-wrench-239.html

You will also need a 1/2 to 3/8 inch adapter unless you have 1/2 inch sockets.
 

meerschm

Member
Aug 26, 2012
1,079
I would suggest the 3/8 drive one.

3/8" Drive Click Type Torque Wrench

this one is on sale.

of course the half inch would come in handy for properly installing lug nuts and other fasteners.

my concern with the half inch, is that 37 ft-LB is kind of close to the lower end of the range on the 1/2 inch drive. it would be ok, but the 3/8 would be better. (and might match your sockets)

why not go all the way, and get a full set, 1/4, 3/8, and 1/2. not sure you would need a 3/4 inch drive for anything on the TB.

I hate going into HF, always seem to find something I need/want.

if you do not have a 3/8 breaker bar, you might look for one to use to remove the belt. easier with the right tool I first used a half inch breaker bar with 1/2 to 3/8 adapter, but it was a lot easier with the 3/8.
 

The_Roadie

Lifetime VIP Donor
Member
Nov 19, 2011
9,957
Portland, OR
floridafitz said:
...I've no idea what 37 lbs/ft feels like.
Huh? Get a 12" long ratchet handle. If all you have is a 10" one, then do the math. Pulling on a 12" long ratchet handle with 37 pounds of force is 37 ft-pounds of torque. Same as pulling on a 10" ratchet handle with 44 pounds of force. (44 = 37 X (12/10)). If you have a 24" breaker bar, it's the same as exerting 18.5 pounds of force. (18.5 = 37 X (12/24)). See how that algebra can be useful?

37 pounds should be easy to estimate because it's around the weight of an average concrete block.

It's MUCH easier to own the right tool, though. Why resist the pull of the dark side of tool acquisition? :thumbsup:
 

meerschm

Member
Aug 26, 2012
1,079
the roadie said:
Huh? Get a 12" long ratchet handle. If all you have is a 10" one, then do the math. Pulling on a 12" long ratchet handle with 37 pounds of force is 37 ft-pounds of torque. Same as pulling on a 10" ratchet handle with 44 pounds of force. (44 = 37 X (12/10)). If you have a 24" breaker bar, it's the same as exerting 18.5 pounds of force. (18.5 = 37 X (12/24)). See how that algebra can be useful?

37 pounds should be easy to estimate because it's around the weight of an average concrete block.

It's MUCH easier to own the right tool, though. Why resist the pull of the dark side of tool acquisition? :thumbsup:

More tools: GOOD!
 

floridafitz

Original poster
Member
Jan 2, 2012
151
Winter Springs FL
Picked up the 3/8 drive torque wrench from Harbor today....$9.95 with coupon. Thanks for the tip! Plan on setting it at 35 lbs since the wrench is supposedly +/- 4%. That way theoretically, I can't over torque it even if it's at the high extreme. Guess I could end up with a torque of 33 at the low end. Anyone see a problem with this approach. If I change the idler pulley as well, is it also 37 ft/lbs?
 

Wooluf1952

Member
Nov 20, 2011
2,663
Milwaukee, Wisconsin
Trying to guess if the torque wrench is + or - 4% would drive me up a wall. Just set it at 37 and don't worry about it.
My '03 calls for 100 ft lbs for the lug nuts. Using your method would get me a possible 92 ft lbs. I'd rather err on the side of slightly more torque. My :twocents:
 

meerschm

Member
Aug 26, 2012
1,079
accuracy of the tool is built into the torque spec.

set the wrench to the specified torque and be satisfied.

fastener torque is like the three bears. you do not want to be too hard or too soft.

in one case the fastener comes loose, at the other end, something goes snap and does not work anymore to hold things together.

idler pulley torque is 37 ft lb is really specified as 50 Nm (37 ft lb)

when you look at the metric spec, it is easier to see that the spec is a nice, round number. there is a good range between "sure to come loose", and "likely to break, (or strip the threads from the block)" just have to trust the engineers have picked the right value.

the +-4% is fine for applications like the pulleys. you would want more accuracy if you were working on the head bolts for a race car, or aircraft.

you may want to google up some hints on use and care of torque wrenches.

leave set to zero when storing.
try not to drop it.
try not to use a crow's foot, or adjust settings if you do.
shot for the middle of the scale, if you have the choice of several.

congrats on the purchase. :smile:
 

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