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There was really no evidence of it contacting the tube ID. The spider COULD have extruded enough though to allow the jaw tips to act like a pain of nipper jaws as the torque is applied and reapplied repeatedly and slowly eat away at the spider possibly. The factory lovejoy jaws have slightly radiused tips and the ones I'm using don't. A lot of possibilities . Gonna take some R&D to cure.
Dayum. Catostrophic failure..... As tight as the clearance is between the jaws and the case not very large of parts could have gotten out. So if they grew out past the jaws then they would start burning on the case. Can't see that in the picture but can you see rubbing on the removed part of the tube? Probably not the way the outside of the jaws don't show anything rubbing. O course if it was gone on your first trip then corrosion may have hid the evidence since.Whatever material you put back in, I suggest running it for a short time then pulling the cover and taking a look before the evidence is ground to powder.
I really think that the spider compressed enough to allow the jaw tips to contact,or near contact,each other and act like nippers on the spider tips. Slowly the tips were eaten away and as the spider was constantly being flung to the OD, the nipping away accelerated as the jaws were able to even more easily contact each other the more spider was lost/nipped away. I think it kind of fed on itself. I'll radius the jaw tips more like the OEM jaws are to hopefully stop that and test out the green spider. I think that it may cure the issue at current power but still need to explore other options as I doubt it will hold up to 300-400 HP.
I thought that with the shape of the jaws it would almost want to squeeze the material into the center instead of to the outside. With the centrifigal force added it would have been about equal. obviousely something went wrong.It seemed like the green was quite a bit tougher even if the specs don't seem to show it.ETA: Actually machining a spider may be much better by getting rid of the 3-D present in the factory spiders. The curve that allows for more angular misalignment greatly reduces the contact area and centralizes the loading. There is virtually no chance of angular misalignment in your setup, so the added contact area of a machined 2-D spider will have more consistent loading and less peak pressure in the spider material.
I remember now-a Guido Coupling. http://cgi.ebay.com.au/BMW-drive-shaft-UNI-GUIBO-COUPLING-E46-E12-E28-E34-E23-/110590056947 Funny thing is that they aren't rated as high a torque capacity as the LJ coupling I'm using. Looked into them early on.
Where did you find the torque ratings. A 760 uses them and weighs 5026 empty with 550FTLB's of torque. With a first gear of 4.71-1 they should be good for at least 2600FLTB's of torque............. Even the lowly 3 series with 200FTLB's and a 4.32-1 should be good for 900..........