Non-Slip Diff Lockers

[R/C Bashist]

So I made my own custom non-slip diff lockers on my lathe using four set screws to grab the driveshafts. They felt really solid, but I took my rig for a good crawl yesterday, and it seems that the set screws have backed off because at the end of the day I had slop again. Has anybody else had this problem? I did use blue lock-tite on the set screws, should I try some red stuff?

[EeePee]

Well, if the blue didn't actually keep the screw locked tite, then... yeah.

Sure everything was spotless clean first?

[WHITE-TRASH]

Clean threads and harbor freight red loctite for me. My lockers stopped coming loose once I stopped using blue.

[mjyjxj]

I think the aluminum threads stretch!

[The Violator]

I use CA glue. Just takes a little heat to break them loose and holds much better vs blue. Red scares me on tiny threads.

[chino63]

Originally Posted by The Violator

I use CA glue. Just takes a little heat to break them loose and holds much better vs blue. Red scares me on tiny threads.

Red is fine. Just a tad bit more heat needed than CA.... well, maybe a few tads more heat.

[JohnRobHolmes]

I've never had good luck with set screw lockers. Even using red they tend to loosen up for me. I think it is because the screws are taking a large force instead of just the spool. From a machinists point of view, seems easier to just make the spool with tight tolerances and good material so it doesn't wallow out.

[chino63]

Originally Posted by JohnRobHolmes

I've never had good luck with set screw lockers. Even using red they tend to loosen up for me. I think it is because the screws are taking a large force instead of just the spool. From a machinists point of view, seems easier to just make the spool with tight tolerances and good material so it doesn't wallow out.

I agree with this, tight tolerance is the way to go for less slop.

My two cents....

I think the pitch on M4 set screws is too coarse for use in lockers (especially aluminum), the steeper pitch angle lends a hand in why they come loose and it sucks that you have to rely on loctite to hold them.

Combine that with the fact that they have somewhat of a point on the end which is designed to bite into the material it contacts. Since most axle shafts are hardened, the set screw can't correctly do its job and eventually loosen. I have ground the tip of the set screws flat combined with loctite with pretty good results on drive shafts but still have one loosen up on occasion. The added torque multiplication of the R&P makes it more of a problem in a locker application. I stay away from any with set screws, especially aluminum ones. I've seen too many come loose or fail at the worst possible time. I still prefer the reliability of traditional steel lockers despite the slop and weight.

[Die-Laughing]

I recommend using red loctite on the clamping screws. You can really crank down the ones with the larger M5 set screws with red loctite and they hold well. Every now and again you'll have one that'll back off a bit but, I've personally never encountered a set screw that backed out enough for the axle shaft to spin. They would both have to back out for that to happen. With a removable cover on the housing, it's nothing a few screws and more red loctite can't fix.

You guys are right though, the slotted style lockers/spools where the axle shaft slips into a precision slot tend to be more reliable but, after some use they do develop some play and therefor can't be considered a no-slop unit. They are great if you want to just throw them in and forget it.

Clamping lockers require a bit more setting up to get them to function most efficiently and if done right, they will hold at least until the next bearing change. The clamping style lockers are a good option for custom applications as well, where the axle shafts need to be modified.

There are ups & downs to both I suppose.

[Die-Laughing]

Originally Posted by chino63

I think the pitch on M4 set screws is too coarse

That's a good point. A finer pitch on the M5 set screw would allow the red loctite to work more efficiently, it would take a bit more to turn out the screw I would imagine.. and if it did break free, the amount of slop would be greatly reduced because of the finer pitch.

[chino63]

Originally Posted by Die-Laughing

I recommend using red loctite on the clamping screws. You can really crank down the ones with the larger M5 set screws with red loctite and they hold well. Every now and again you'll have one that'll back off a bit but, I've personally never encountered a set screw that backed out enough for the axle shaft to spin. They would both have to back out for that to happen. With a removable cover on the housing, it's nothing a few screws and more red loctite can't fix.

You guys are right though, the slotted style lockers/spools where the axle shaft slips into a precision slot tend to be more reliable but, after some use they do develop some play and therefor can't be considered a no-slop unit. They are great if you want to just throw them in and forget it.

Clamping lockers require a bit more setting up to get them to function most efficiently and if done right, they will hold at least until the next bearing change. The clamping style lockers are a good option for custom applications as well, where the axle shafts need to be modified.

There are ups & downs to both I suppose.

Never owned a set of yours, just my experience with ones I used in the past. Failures that I either had or witnessed were in heavier vehicles (8lb+) and most running 3s brushless which I'm sure compounds the issue.

Originally Posted by Die-Laughing

Tat's a good point. A finer pitch on the M5 set screw would allow the red loctite to work more efficiently, it would take a bit more to turn out the screw I would imagine.. and if it did break free, the amount of slop would be greatly reduced because of the finer pitch.

Didn't know yours used M5 set screws. Would be nice to see a finer pitch set screw.

Like I said, grinding the contact face of the set screws (Tamiya U-joints) I used on drive shafts in conjunction with Loctite yielded the best results when used on a non drilled hardened shaft. Following that, I ended up drill/tapped the other side of the joint and just used two set screws.

[mjc597]

What about if the spools used pins like what is used for the output shafts on transmissions and axles?? I'm no expert just had the thought running through my head.. I've tried grip fab no slop lockers before but didn't have luck...might not work out as good as it sounds, but maybe with the right materials used for the axle shaft and pin and spools, it would work???

[Die-Laughing]

The set screw style lockers are more of an "advanced" style locker. They require careful setup & proper installation for best results. The slotted spools are much easier to use, just toss them in and go.

The idea combining both the slotted style spools with threaded pins is good but, there are a few issues I can think of right off the bat. The axle shafts need to be modified so, it would either be a DIY type of thing or the person supplying the spools would also have to supply modified shafts and most everyone already has axle shafts when buying aftermarket lockers/spools. Another thing is that the slotted style spools don't really have a big issue with wallowing out to the point of axle shaft spin so, if you wanted to achieve a no-slop situation with this idea, the axle shaft hole & pin would have to be a very tight tolerance and then you're running into problems with compatibilty between axle shaft manufacturers, different ring gears, etc. I just don't think its practical. I attempted something similar once before, I used a slotted style spool with the addition of set screws. It was on one of my ARB spools. I could only fit M3 set screws while retaining the look I was going for. I didn't like the size of the set screw I had to go with so, I scrapped that idea. Someone out there has a set of those though. I wanted a reliable slotted style spool but with just enough set screw for it to be no-slop. I think it's do-able, just not if you're going for a specific look.



I dont do these anymore but, a couple set screws in there made them ugly IMO.

These lockers, you either love em' or hate em'.. Its been that way since the beginning. I can understand that.



You locker looks great.. Nice work.

[Die-Laughing]

I don't mean to turn this thread into about my junk.. There are all sorts of good lockers/spools out there. I believe "Felsenfest" is the originator of this clamping style locker like myself and R/C Bashist have shown you. They all have their upsides & downsides I suppose.