Hex grub screw

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What does this screw do? I noticed my front wheel bearing seems tighter than the other so I’m wondering this nut is responsible for how tight the bearing sits?

The grub screw just holds the hex pin to the axle stub, it has no impact on how tight the bearing is. You may have a bad bearing if it’s getting hard to spin.
 
What does this screw do? I noticed my front wheel bearing seems tighter than the other so I’m wondering this nut is responsible for how tight the bearing sits?
Welcome!

The wheel center grub or set screw puts pressure on the pin that slides in to hold the wheel hex in place in post #1. It's the same all around for the 6S rig. So there should be no extra tightness. I would advise pulling the front wheel hex off and making sure you have nothing between the hex and the bearing...not trash, dirt, etc. Next check the bearings the wheel bearings should be checked often for bashers and the stock bearings are not the greatest. Check both bearings there is one on each side the outer and inner. I find my inner which is the larger go bad faster and on some rigs like the Typhon/Kraton change at least some after 2x bashes.

Summary how tight the grub screw is in a correctly operating rig would not cause the front bearing to be tight...unless you have other issues creating this.
 
This is how I did one of mine.

Remove steering block from car. Clamp the hex hub in a vice and punch out the pin. It will take several pretty good blows with a hammer to dislodge the pin. Remove all other parts from the cvd axle. Then drill a 3/32 hole through the hex grub. Heat it with a propane torch to break down the thread locker if you haven't already done so. Then put the cvd axle on top of the vice and pound a t15 bit into with a hammer to broach it. Put the hex back on and partially insert the pin to hold the hex hub to the cvd axle. Clamp the hex in a vice and use the t15 in an impact drill to remove the grub screw.

The threads inside the CVD axle on mine were messed up. Whoever assembled mine went way over the torque specs and managed to bend one of the hub reataining pins so that even with the grub screw removed it still took a vice, hammer, and punch to remove the pin. Horizon had covered the parts to replace the CV's, Blocks etc... I just got bored one day and decided to see if I could salvage some of the parts.

Edit: Added a step to clarify.
This happened to me today. I wonder what tools you use to punch out the pin, besides a hammer and a vice?
 
I want to replace the plastic steering blocks with HR aluminum blocks. I couldn't get the grub screws out of my front hexes, even with a lot of heat and good drivers, so I removed the steering blocks, driveshafts, and hexes as one unit. I bought a set of new driveshafts and a set of hexes from Jenny's to put into the new HR steering blocks.
What does this screw do? I noticed my front wheel bearing seems tighter than the other so I’m wondering this nut is responsible for how tight the bearing sits?
All the grub screw does is prevent the pin in the wheel hex from coming out. If you need to get the hex off for maintenance, you need to remove this screw to get the pin out and remove the hex.
 
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I just got a new Typhon 6s and was giving it a once over and on the right rear hub this grub screw is so tight it twisted the allen key when I tried to remove it. I'm shocked it didn't strip out. All of the others came out no issue. I don't have anything I can use to heat it up and WD-40 didn't loosen it at all. I think I'm going to contact Horizon and ask them to send me parts to rebuild the hub.
 
Yeah heat is your best option. They are not easy to get out. Even more of a pain to drill and tap out if you do strip them. A soldering iron would be a good investment for many things with RC's.
 
I just got a new Typhon 6s and was giving it a once over and on the right rear hub this grub screw is so tight it twisted the allen key when I tried to remove it. I'm shocked it didn't strip out. All of the others came out no issue. I don't have anything I can use to heat it up and WD-40 didn't loosen it at all. I think I'm going to contact Horizon and ask them to send me parts to rebuild the hub.

I had a similar experience. Three of four came relatively easily, one of four had me approaching the threshold of 'this is too much force, need heat or I'm going to snap the driver' and I was a moment away from reaching for the torch when it broke loose. Enough crumbled threadlocker for all four screws fell out of this one hole. The worker at the factory must have given it a big squirt inside the axle threads and hoped for the best.

You'll probably need heat for yours. You can pick up a small butane torch for about $10. Even a common cigarette lighter may work, but may be hard to get the screw hot enough quickly without overheating other components.
 
This happened to me today. I wonder what tools you use to punch out the pin, besides a hammer and a vice?
I had this issue with Kraton EXB and it was awful. Sorry this has happened, its no fun at all. If you can stand giving up the car and sending it back for new then do so, but i didn't want to wait that long and thought i'll find a way to get theses out. Retrospect i should have just returned it. I had two strip out my first time trying to take them off thanks to the nuts at the factory using enough loctite to hold a train to the tracks...all for a screw that doesn't require any.

To pound the pin out i used a small finishing nail which i clipped the tip off. You could also just use one of the pins you can get at to pound into the stuck one but its a close fit size wise, so i suggest a nail with smaller diameter to be sure all force is transferring to the pin the first few blows. Also be sure to brace everything as you are going to have to really whack it a couple times and you don't want to bend anything.

The first one i couldn't even pound the pin out so i drilled out the grub screw through the hex with the pin in and it was as bad and tedious a process as you might imagine. There is no way to get a screw extractor in there, its too deep. The heat of drilling it just melted the remaining bits of grub screw into the threads in the end and i've never got that out so I can't put a screw in there to hold the pin any longer.

The second i was able to pound the pin out but was done with the fun of drilling the grub screw only to not be able to get a screw back in there in the end anyway so instead i just drilled through the hole in the drive axel to shave off the end of the grub screw. Much easier. This allows the pin to slide in but just like the other, the screw line is blocked for putting another grub in to hold the pin...... but i live without. You don't really NEED the pin held in place, its just way more convenient. When you crank wheels on the pin is going nowhere. its just a small pain in that the moment you take the wheels off the pin just falls out and the hex slides off. If you are aware and know that's going to happen you can live with it and its no big deal. Generally when i take wheels off taking the hexes off is just a close step behind that anyway. Now it just happens automatically. :ROFLMAO:
 
I had to drill the screw out completely. I used a drill bit with a size of 4 mm (5/32”). Outdrive thread remained intact.
 
I had a similar experience. Three of four came relatively easily, one of four had me approaching the threshold of 'this is too much force, need heat or I'm going to snap the driver' and I was a moment away from reaching for the torch when it broke loose. Enough crumbled threadlocker for all four screws fell out of this one hole. The worker at the factory must have given it a big squirt inside the axle threads and hoped for the best.

You'll probably need heat for yours. You can pick up a small butane torch for about $10. Even a common cigarette lighter may work, but may be hard to get the screw hot enough quickly without overheating other components.
I ended up not having any luck. I contacted Horizon and they sent me the parts to rebuild the hub.
 
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