Trouble with set screws!
 

ok, well i finnally got the new BL e-maxx diffs for my e-maxx and installed them. then i went outside to drive it, set screw (witch had thread lock on it) on the pinion comes off. reset it with thread lock, came off again. then i clean the motor shaft and inside the pinion out and reset it with a ton of thread lock and stripped out the set screw getting it in their so tite. then once again it came off. i finnally got it to stay by getting a new set screw, cleaning and slightly scraping the motor shaft and inside the pinion, plus cleaning out all the old threadlocker and re-applying it. then it ran great this past week and now the set screw inside the tranny on the input shaft that the manufacture set came out. :whip:

http://i46.tinypic.com/2dl0osp.jpg

is their anything i could possibly do to have any better luck with these things? i'm already going to have to order a new gear and pinion for the tranny but can i do anything to make sure it's not going to come out again? or do you think i should scrap this tranny and get the new e-maxx tranny (would it fit?)?

by the way, i'm using great plains blue, removable threadlocker.

Since it's inside the tranny, why not use the red lock-tite?

is that the permanent lock-tite?

Yep.

Is it really "Permanent"? You won't be able to losen it, never again? :oh:

It's not that permanent, it can be undone, just takes a little muscle and sometimes some heat. Have you been giving the loktite a chance to setup after you put things together before you go out and run again? Also how old is your loktite? I had some trouble racing last year, my loktite was about 5 years old. I even wound up using red loktite on my pinion as I figured out my gearing and wasn't changing it, I was still able to get it off at the end of the season.

No. It's not permanent, at least not to my grip. It depends on percentage of surface area covered. Maybe my ol red is getting old, But I use it on my set screws.
I have been trying green penetrating Lock-tite and its so thin and runny it's scary, it did set pretty good as thin as it was.

Not all set screws are equal. If it is just flat on the end, it will come loose easier because it will just press against the shaft. The kind you want have a dimpled or cupped end on them, they will actually bite into the shaft and hold much better. Old locktite may not set up, and even fresh locktite should sit overnight or 24hrs + would be better.

Is it a myth that loc-tite sets up faster in a squeeze(threaded) rather than just sitting on the suface open to the air?

Loctite is anaerobic, it cures in the absence of air.

Blue- temporary
Red- semi-permanent
Green- permanent

Even though green is permanent, it will remove with heat.

The best method I've found is grinding a divit, so that the setscrew can 'fall into' it. Then you can get away with blue or red loctite. The best way to do that is with a diamond ball burr set for your Dremel. Just do a search for those, they're cheap and last a loong time.

Also, to find the exact spot to grind, install the pinion so it meshes perfectly with the spur, and screw the set screw down. Then remove the pinion. The set screw should have left a tiny mark of some kind on the motor shaft you can use as a guage. Or, if that doesn't work, use a Sharpie and mark up the flat spot of the shaft. Then, install the pinion where it needs to go to and set the set screw, and then remove it. Where the screw was, the Sharpie marking should have been scuffed/removed at that spot.

wow, thanks for the info guys!

and yes i've let my lock-tite dry for about 24 hours every time. it is however a few years old but still can be hard to remove sometimes. i think i'll buy some red lock-tite when i go to town next time. but the set screw in the tranny that came out is pretty ground down on the bottom so i'm going to need a new one in order for it to grab well on the round shaft.

Wait a minute: do you have a flat spot on the motor shaft? If not, you should definitely grind one first. Just use a Dremel. Just be sure to cover the motor bearing with a baggy (just poke the shaft through the baggy), or use electrical/duct tape.

NVM, I just relooked at the pic and see that it's not the motor shaft. Duh. But still, grinding a slight flat spot where the set screw goes can help a LOT.

Uh wait.. are we talking about the roll pins?

Try using the info provided
 

What BG said was to grind some sort of locking point into the shaft itself. It is best to have some sort of dig point on the shaft for the set screw to tighten into. Then it will hold up better during operation.

Loctite is one of those chemical miracles of a sort. I attended a class for loctite a few years ago while working at Universal Studios Orlando, and what the company told us then was that their product actually hardenes up under pressure when you apply a tightening force to the hardware it is applied to. It does not dry because of the air around it. Of course it will harden up or cake up over a long period of time, but that is not the purpose of using it. You can even apply it and put the item right back into use, but they suggested that you let it cure for at least an hour before using the item. None of the lictite products is really permanent, but as noted one loctite product is stronger then the previous one as you climb the ladder. We used loctite on everything for putting the rollercoasters back together at "Islands of Adventure". I worked on the Dueling Dragons, The Incredible Hulk, and the Mummy coasters, and without loctite they would have come apart farely easy under the pressure of normal operation.