Torque-to-angle clutch bolts. What's the going method?

I'm sure this information is on here somewhere, but I haven't had any luck finding it. Sorry. Anyway, I'm removing the clutch on my '97 R1100GS and I noticed that the bolts that hold the pressure plate to the flywheel require being tightened to a specific wrench angle.
I also understand that the bolts aren't reusable. I have new bolts and I have a torque wrench but I don't have an angle wrench. If I understand the manual correctly it states to oil the threads and initially torque the bolts to 40Nm, then give them an initial 32 degrees of tightening.
I don't think an angle wrench is in most people's tool boxes. Is there a decent way to do this without the special tool? If I need to I'll buy the angle wrench. I did a web search and it looks like you can get an angle-attachment for a standard ratchet for around $10. Not a big deal, but I'd like to know if it really is necessary or not.
Thanks.

For the 180° head bolts I eyeball it. However, if you are uncomfortable with eyeballing it you can make your own angle gauge with a piece of cardboard with a circle on it. Cut a hole in it for the ratchet and mark off 32°.

Absolute precision is not critical. 32+-2 is fine.

Jim

For ten bucks, just get the angle adapter. Then give it to the next guy who needs it.

Yeah, you're probably right. It's just that often the manual (any manual) that you're using insists that you MUST use the special tool. In some cases this is legitimate and there really isn't a good way to do it without the tool, but a lot of the time there's a more conventional way of doing the task with totally acceptable results.
I'll probably buy the angle gauge, though. I really believe in the proper tightening of fasteners. I used to be an aircraft mechanic so maybe it's a carryover from those days.

If the bolt gets turned 32°, it doesn't care how you got there. The BMW tool is pretty much the same as the others on the market; it's the outcome that matters. You can make a protractor out of paper if it gets you to 32°.

$10 is cheap compared to the new TechAngle wrenches for nearly $500.

This is what I used on a R1100 recently. Makes the job uber simple. There are cheaper units but I like this puppy...

http://www.amazon.com/Lisle-28100-T...3088&sr=1-4&keywords=drive+torque+angle+gauge

Torque to yield bolts are getting common and you can never have too many tools.

Circumference is Pi X D. So if your wrench is 12" long then D is 24". Pi=3.14159. C=75.39816. So 32/360 X 75.39816=6.70205 or ~ 6.7"

Move the end of the handle of your wrench 6.7" across the arc which will equal 32 degrees, if you have a 12" wrench.

But I don't have a circular ruler, either

You do not have a piece of string and a pin?

Might be this is beyond your skill set and you should have someone else do it!

Jim

Yeah...maybe you're right. I could sell the GS and get a Harley. You just need a hammer and adjustable wrench for those, right?
A chrome hammer and chrome adjustable wrench, that is.

Tighten to the correct torque, then mark the flywheel at a corner on each bolt. Turn the bolt until the mark is in the center of the next flat. Voila`!

Ta da. it's done. Nice one Mr. Moore.

If that, with your eyeball, gets you to 32° then OK. I just had an Airhead bike come through that lost its flywheel bolts. The repair will be well over $1000 and that is with used parts. Clutch carrier, disk, bolts, other clutch parts, and the labor to remove the crank completely and repair the related damage.

Or a $10 tool that you will still have afterward. Your choice.

I'm going to get the tool. It's cheap enough as to be a non-issue and like I said, I'm particular to proper fastener procedures.
I just asked originally as much out of curiosity as anything else. This is my first experience with using torque-angle instead of conventional torquing. Sorry, I'm sure the terms aren't technically correct.
The idea of torquing to an angle rather than a foot-pound or Newton-meter spec makes a lot of sense after I read up on it. Seems to take a lot of the variables away and make for a more accurate torque.

P.S. Anton, I've sent you a few emails from the email address that's a lot like my username here but I haven't heard back after the first response you sent. Have you been getting them? Thanks again.

Pretty slick except for the fact the socket covers the bolt so you can't see the flat .

One would have to turn the socket guessing if you've gone far enough, remove to inspect, turn some more, inspect, turn some more, inspect, whoops.. too far.

I prefer one smooth, fluid motion when torqueing. Spend the 10 bucks.

I think he means the next bolt is to be used as a reference.

Jim

Or you could mark the socket.

Hey I knew someone would come up with a super simple way. BTW, how do you hold that tape measure in the arc?:huh

Some of you guys may be overthinking this one. How close is your initial torque? When was the last time your torque wrench was calibrated? If your wrench is off by 10%, how many degrees is that?

The distance difference between the straight line between the two points and the distance across the arc is very small. The arc length is less than 10% of total circumference. So JVB's string and pin works great.

When I get some more coffee in me I will figure the actual difference.

Initial torques on angle-torqued fasteners are chosen to be the most repeatable ones you can have, based on the properties of the materials. That's the whole point of their role in this method: make the most predictable starting point possible. In my experience the torque rises very rapidly when you reach the initial torque, so a few Nm either way will make a very small difference in angle. Stop the torque and start the angle before the variables start to affect the accuracy.