RWD - Update: Unable to Torque Crankshaft Bolt

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Update: Unable to Torque Crankshaft Bolt 200 1980


I thought I was pretty clear to you how to get the bolt tight but I have a little extra time so I can tell you more about the reasoning I use to get to the approximate value they are calling for.

Yes that is the method I use on all my cars.
The bolt is the same in all the crankshafts even though the pulleys change from being a solid one to a split one with shims used to adjust the belt for the A/C. That's why you have six bolts.
Later the setup changed to a rubberized damper keyed to the belt sprocket only and a big washer to sandwich everything.
The torque values for either method works out to be the same to hold that belt sprocket in place.
Yes, its a lot of torque and is why you must get everything under it (belt guides) flat and straight or you can break the thin sprocket.

The method for turning, after preloading, works for most people who don't have a 3/4" drive, 150 Foot Pound torque wrench hanging on a wall because its too large to fit into a tool box.
I personally would not buy one unless I did rear end differential work.
I know this, because I inherited one from a close neighbor who passed several years ago. He used it for crushing a pinion nut washer on his Dodge truck. I don't think he ever used it again.

The impact driver works the best on the manual transmissions with the parking brake set or having the car on the ground and in gear.
Now that I have one car with an automatic, but have not needed to change a timing belt, as of yet.
That day will be as interesting as yours on the need to lock it that engine up.

You can reach that amount of torque with a half inch drive torque wrench. But it's not nice!
It's actually not very good for the torque wrench to use it at its extreme.
When it's used at the most upmost end of its range, it will not maintain its accuracy for being pushed to its limit.
A clicker wrench is more susceptible to stress because of the spring arrangement inside.
An old steel beam one can get bent and it still will work. All you is reset the needle arm back over the zero on the scale.
Trouble is but it's very hard to read the scale sideways when pulling hard with such a short length and the click is a nicer feature. I keep my beam one to check calibration of my clickers!

Torque wrenches are like pressure gauges and are meant to be installed where the gauge operates the majority of its time in the middle of its total range.
You would not install a 100 pound gauge to measure 15 psi or less system. If you wanted to read any small variances say around 10 psi it won't be as accurate as a 30 psi gauge.
The gauges themselves are calibrated to be "spot on" in their mid range to begin with.
The +/- tolerance accuracy is specified as its mid range of usage.
I use a 3/8" clicker to do spark plugs, drain plugs and so forth. This is because it fits in tighter places and their extensions and such are lighter.

I know if you read the Bently manual, they have a misprint of it saying 90 degrees, when it should say 60 degrees.
The hex head on the bolt has six flats. Divide 360 degrees that it takes to make a circle by six and you automatically get sixty degrees or rotation.
This make more sense if you think about it for mechanics to get the angle correctly without special tools!

In all cases of tightening, you are stretching an area of the body mass between threads and the top of the head. Preloading a certain amount stress is to remove looseness and provide tension or a starting point. The whole idea is tension against vibrational forces and rotational forces.
So on engines the idea of not using a torque wrench is ludicrous and so it is why, you have specifications written for specific areas.
On other things, like engine accessories, using brackets and alike you don't get anything specific but you learn quickly that too much or not enough can bring you grief!
You learn what "tight is" from experience!

Take a wheel nut for an example, that gets tightened to 80 foot pounds. That's a lot of torque in reality but who wants to have any to come loose?
How many of those get stripped or studs broken by the tire shops? That scares me somewhat, but apparently, that area is overly engineered to help get a better outcome, considering the motoring public options of servicing wheels and tires.
There are four nuts on light weight economy cars or five and up on heavier vehicles. Weight and larger diameters increase the forces the wheel can be subjected too! The more is better and at a point they get larger studs and nuts like on 18 wheelers.

The call out is of 122 for only one bolt and it can be done this way. First of all the bolt has a lot more bulk than the wheel studs do.
The diameter down there being held together is a lot smaller, it has nice snug fitting parts, if compared to a wheel rim and the joint is keyed to be driven by the key, so where can it go?
If you get it tight, as in even close, to the specifications called out, its not going to go anywhere.
Remember the 45 ft lbs. is a setting of preloading.
The engineering behind this is wanting almost three times that as a final torque value, of which I think, is a bit much for this joint. It is what it is though!

I'm not a rocket scientist, so I try to live within my means and/or tools and justly getting it close with the use of a tool that I know can tighten stuff up really tightly.
A half-inch impact and a half-inch torque wrench are made to be rather equal in their capabilities of work assigned for them to perform.

Do the best you can, it will come out all right!
As my point being is that somethings are just overly engineered, for safety to cover their buns, over the actual purpose.
This is only a good thing considering the general public and the way it is today!



New Timing Belt and Crankshaft Pulley in B21F Engine [200][1980]
posted by  1908242DLa  on Fri Dec 28 12:26 CST 2018 >

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