how to torque transmission allen head mounting bolts ??? Late model airhead

R

r80andr100rt

New member

• Feb 14, 2015

• #1

I don't see any way to get a torque wrench on these allen head screws. What do you guys do? The only idea I can come up with is to torque a bolt some where else to get the "feel" of how tight they should be then wing it by feel.

 

20774

Liaison

Staff member

• Feb 14, 2015

• #2

I'm not sure exactly which allen heads you're speaking of, but if there's clearance to get the torque wrench in there, they make allen wrench adapters for torque wrenches. If there's no room, with some machining, one could build an extension to the torque wrench but then you would have to adjust your torque values depending on the change in length. For other places, one that I can think of such as the bolts that connect the driveshaft to the transmission output flange, usually what works successfully is blue Loctite and a good "grunt" with a regular tool kit wrench. In your situation, possible some Loctite and a good enough attempt to tighten the head would probably work.

 

pglaves

#13338

• Feb 14, 2015

• #3

Allen-head socket. Proper length extension. 3/8" drive torque wrench.

 

lmo1131

New member

• Feb 14, 2015

• #4

Allen-head socket. Proper length extension. 3/8" drive torque wrench.

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e.g. metric allen, of course

And possibly even mo' betta... . "Ball end" allen sockets. Although if you get too far off of "perpendicular" it will affect torque values somewhat.

 

donbmw

New member

• Feb 14, 2015

• #5

I just snug them up real good.

 

godfather

New member

• Feb 14, 2015

• #6

PGlaves said:

Allen-head socket. Proper length extension. 3/8" drive torque wrench.

Click to expand...

+1 Just did my 78' /7 like this

 

lkchris

Active member

• Feb 14, 2015

• #7

lmo1131 said:

Although if you get too far off of "perpendicular" it will affect torque values somewhat.

Click to expand...

Not to mention the fact you'll probably strip out the hex in the bolt head.

 

toooldtocare

Active member

• Feb 14, 2015

• #8

donbmw said:

I just snug them up real good.

Click to expand...

Me too.

 

dennisdarrow

#4869 Earned Lifetime mem

• Feb 15, 2015

• #9

toooldtocare said:

Me too.

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Yup.........It's called a calibrated wrist.........God bless.......Dennis

 

20774

Liaison

Staff member

• Feb 15, 2015

• #10

...as opposed to "running it in until is smokes, then back off a quarter turn..."

 

R

r80andr100rt

New member

• Feb 15, 2015

• #11

Ended up with " calibrated wrist" method. There is no way to get a proper tool on this without sawing off the shifter linkage boss.

 

20774

Liaison

Staff member

• Feb 15, 2015

• #12

Yeah, this is one of those locations that I try and remember how difficult it was to break it loose and then repeat that on installation. Hopefully, it's not a long time between those points. But certainly snug is good here...and it's easy enough to recheck a few times after some heat cycles...if it's still tight, ya done good!

 

akbeemer

SURVIVOR

• Feb 15, 2015

• #13

Hexhead fasteners seem to me to be among the easiest to bugger up. It is important that you use good tools made of quality steel and with crisp edges. I supose that is why BMW went with Torex fasteners on the newer machines.

 

nrpetersen

Curmudgeon

• Feb 15, 2015

• #14

I agree the torque level isn't that critical as there's plenty of thread engagement and it is a static application.

But if you really want to torque it, cut an unplated hex key to fit. Then cut a slot in an old 3/8 inch drive socket to engage the hex bar handle of the hex key. Measure the increase in the torque wrench operating radius and reduce the wrench reading proportionately.

Note that if the torque wrench handle is at right angles to the hex bar, the increase in effective radius is essentially zero and no compensation is needed.

 

lkchris

Active member

• Feb 15, 2015

• #15

Get a "stubby" hex

 

M

motodan

Active member

• Feb 15, 2015

• #16

One of these?

http://www.snaponindustrialbrands.com/cat-19-1-87/heads-for-pre-set-torque-wrenches.htm

 

80092

Member

• Feb 15, 2015

• #17

PGlaves said:

Allen-head socket. Proper length extension. 3/8" drive torque wrench.

Click to expand...

Is the allen in question the lower left fastener in front of the shift lever ? If so when I removed that fastener the shift lever was in place and blocked the use of a ratchet. I need to check clearance of said fastener to see if a ratchet can be used with the shift lever off .

 

pglaves

#13338

• Feb 15, 2015

• #18

See the bottom half of post #4. Use a ball-end allen socket. Kent is right in post #7 about some applications but the fastener at this location has a full depth - not shallow - head socket and can easily take the specified torque even using a ball end. You will have the alignment of the extension at maybe a 15 degree angle to the threadline of the fastener. You could alter the torque spec but I wouldn't bother. Just set the wrench and tighen the capscrew. I have done this literally dozens of times.

 

J

James.A

former Airmarshal-IL

• Feb 16, 2015

• #19

At the risk of being labelled an "apostate", I have never used a torque wrench on those cap screws. ( hell, I probably just called them the wrong name ) The so-called "mechanics feel" has always worked for me.

 

pglaves

#13338

• Feb 16, 2015

• #20

James.A said:

At the risk of being labelled an "apostate", I have never used a torque wrench on those cap screws. ( hell, I probably just called them the wrong name ) The so-called "mechanics feel" has always worked for me.

Click to expand...

That is absolutely true. But the original question was how do I use a torque wrench at this location. "Don't bother" is an answer, I suppose. But so is the prescription to use a ball end allen socket and extension on the torque wrench.