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snmhanson

Getting correct tensions?

11 posts in this topic

Does anyone here actually use a torque wrench to get all of the bolts to the correct tension per the manual? I went to the local auto parts stores to see about getting a 1/4" and 3/8" driver torque socket wrench and they didn't have any. They said they can order them but that they are quite expensive. If it is all just done by feel can someone give me an idea as to how tight some of the different ft-lbs should be? For example, how many ft-lbs would something be if I just barely snugged it up a little with a 1/4" drive? How many ft-lbs would it be if I cranked a bolt down as tight as I could with a 3/8" drive? I have a 1/2" drive torque wrench but I was told reducing it to 3/8" or 1/4" will throw the readings all off and it is really too big to be of much use anyway. Any good ways of doing this would be great. Thanks.

Matt

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From what I've experienced, a small reducing socket will have a negligible effect on the torque accuracy. If you use a longer extension, that's when you might have a problem. I've done some experimenting and have found an average 2-3 pound difference with a 6" extension and a 1 pound difference with just the reducer. I have a Husky wrench that goes from 10-100 pounds in 5 pound jumps and with .5 pound increments on the adjustment ring.

My advice is to just bump up the setting a couple of pounds and not worry about it :) ...SC

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I torque almost everything I'm too cheap to not torque parts. The way I figure it is, standard torque settings based a fastener size are one thing, but when a manufacturer spends the extra money to publish different torque settings for specific fasteners there must be a reason, every special action costs the manufacturer more overhead ($1.00 times 100,000 units is $100,000.00 of cost) Steel bolts into aluminum, or tighten parts that have O-rings, copper gaskets, or large sealing areas that could warp and destroy high dollar parts are some reasons that come to mind without much effort. Grangers, local tool suppliers (for contractors) and the internet are all good places to get torque wrenches.

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If it is all just done by feel can someone give me an idea as to how tight some of the different ft-lbs should be? For example, how many ft-lbs would something be if I just barely snugged it up a little with a 1/4" drive? How many ft-lbs would it be if I cranked a bolt down as tight as I could with a 3/8" drive?

Matt

I have to agree with Superat. There are torques specified for a reason. I work on Army helicopters and I can tell you that the correct torque, or incorrect torque at that matter can be a matter of life and death! We just had a issue today about a large bolt that sheared at the tailboom. This very well could have been due to over/under-torque.

The second issue is don't go too cheap if you decide to purchase a torque wrench. Look at their level of accuracy before you purchase. Yamaha has torques that are exact with no variance. Also a torque wrench remains accurate for a short amount of time and requires recalibration occasionally.

We paid good money for these machines and I believe they are worth the extra effort when we work on them.

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Using a socket adapter will have no effect on the torque that you are applying. If you use a crowsfoot and point it foreward then this would affect the torque setting, because it extends the total lenght of the torque wrench, I agree that yamaha puts down a value for a reason and you should be torquing the important bolts. I wouldn't bother torquing the screws that hold plastic and stuff like that, but triple clamp bolts, engine bolts, driveline bolts, definitely torque them, also use I use antisieze and or corrosion preventative compound on all my fasteners, helps out in the long run

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I have two torque wrench, one 1/2 '' drive 25 to 250 ft/lbs and one 3/8 drive with 1/4 '' adapter that goes from 3 to 20 to 225 inch pound. And yes I use them regularly. Specially for the small size bolts. It's so easy to strip the threads in magnesium.

With time you will develop a good feel for tightening, but if you want to be safe. Torque it.

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Antisieze is a great idea but be carefull using any lube on bolts that are Torqued. Most torque values are for "dry" threads. The only bolts I can think of from Yamaha (WR450 anyway) that require lube are the head bolts and they use the "rotation method". When I was a kid I was helping a friend rebuild his HD Baja 100, we could not find a torque value in the manual and called the local HD dealer. The service manager told us "just tighten them down, if you break a stud come on down we have them is stock" I have never forgoten that!

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For a hand "feel" of torque specs: finger tight is typically about 3-5 ft/lbs; using a 1/4" rachet, "snug" is about 10-12ft/lbs, "tight" is about 20 ft/lbs.

3/8" rachet: "snug" is about 16-18 ft/lbs, "tight" can go up to about 45 ft/lbs or more.

I'm not a big guy, 6'2" 175#'s, so this may give you some aid as to how much pressure "snug" and "tight" really is.

Also I rebuild/work-on old Dodge and Plymouth cars/trucks and this is where I picked up the hand "feel" for torque specs. I've also broken off many fasteners and learned that breaking stuff just takes too much time and effort to fix.

Harbor Frieght tools sells a 1/4" torque wrench for $10-$15. It's worth the small $$ to buy one of thier wrenches so you have an idea where your at. (I know, China junk but at least it gets you close)

I have 1/2", 3/8" craftsmen torque wrenches that I use about every weekend and the cheapo 1/4" that I seldom use.

Best advise I have is to always use a 1/4" rachet whenever possible. You reduce your chances off over-torque and breaking stuff. If your using open/boxed end wrenches, up to about 17mm, the 1/4" drive specs apply. Steel bolts into aluminum threads is very easy to strip. And a 2 ft/lbs difference isn't going make much difference in most applications. K

edit: Sorry for the ramble :)

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Thanks for all of the advice. I think I'll order at least a 1/4" drive and probably a 3/8" as well. Besides, you can never have too many tools.

Matt

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I just installed my wheels after having a new set of tires mounted. I have been lucky in the past, not owning a torque wrench, and guessing correctly, but I am going to borrow my neighbor's tomorrow to re-check all of my fasteners.

I am getting anal in my old age. :)

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