Bicycle Mechanics - Ultegra crank/bb question.

My new Ultegra crank arms have loosened 3 to 4 times and continued to do so this morning. I'm using the Octolink cranks with the splined bottom bracket and have re-attached and re-torqued them several times, it's getting really frustrating. I noticed that there was quite a bit of grease/chain lube (?) in the crank/spline interface area and was wondering if this could be contributing to my problem. As of today only the drive side came loose and I thought that maybe chain lube or grease from the bottom bracket was somehow working its way into this area. When I installed the cranks I removed the packing grease and put them on without additional grease or lube of any kind (as per Shimano's instructions). Would anyone recommend that I: 1) pull the cranks and completely degrease the spindle/crank arm with a solvent like WD40, 2) dry with a rag, and 3) re-install using Loc-Tite on the fastening bolt threads?

On a side note I have to say that I'm amazed at how unreliable these crank systems can be. A couple of years ago I upgraded to a splined system on my mountain bike with much the same problem. It took 2 bike shops a total of 5 attempts to get it right. I built a cheapo commuter bike with an old set of Seguino cranks with a square taper bb-one easy installation with absolutely no problems after hundreds of miles of commuting and multi day rides-completely effortless and reliable.

Octalink does not need lube to work or prevent seizing up. It is more persnickety
about how it goes together than square taper BB and easier than it should be to
slightly malalign the splines and tighten it up a bit off so full lock up of the splines
does not occur and the crank loosens up in riding. Check the splines after clean
up of all the grease for damage to the splines, usually on the crank. If they look
a bit chewed up on the ends of the splines then they weren't fully seated when
tightened. This is not fatal to future use if the splines are bit buggered. Clean
up the chewed parts if any so nothing protrudes much and interferes with fit and
put the crank on and push firmly with wiggle til it slides on, note distance of inside
of crank to BB and pull crank out a bit, rotate to the next spline and refit. Do this
with each successive spline until you have rotated the crank in a complete circle and hit all the splines. You may note one position that goes on more easily and closer to
the BB than others: that is the position to use, but make sure the crank is fully
bottomed on the splines manually before cranking up the torque wrench. Dont let it
slip out of position. Once you get it right it won't come apart. Helps to have a
socket type 8mm allen tool also. An Alien multi tool will NOT do. At least use a standard L type 8mm allen tool, not a T handle either. After two bobbles and a chewed up spline my three octalink road bikes have been tight since last assembly in '01. Steve

I would clean all traces of grease from the parts with a degreaser (not WD40) and make sure they are clean and dry. Reinstall and use a torque wrench to tighten to Shimano specs. If they loosen up again, then put a spot of locktight on the bolt and retorque.