New build - Loose gear questions
 

I just bought a Honcho Kit and started putting it together, but I have what seems to be excessive play in the axle output shafts and the Spur assembly. Both issues seem to be from the pins that hold the gears. The gears slips over the pins but the shaft can still move in and out.

1. Axles - After I put them together then spin free, but the output shaft moves in and out ~1/16.

2. Spur Assembly - It moves in and out 1/16. I tore it apart and double checked to make sure I didn't leave out a spacer or anything.

Am I missing something or is this amount of movement normal? I wouldn't think so. After the gears suppose to snap over the pins or just rest freely?

Thanks!

There is typically a little play, and 1/16 seems little enough. Too tight a fit would probably be worse. if it bothers you that much, you could just throw a sime in there.

Thanks for the suggestion. I have never owned a car where the spur can move back and forth across the pinion, but maybe these are different because they are meant to go slow. 1/16 is actually a lot considering the spur and pinion are the same width. It causes noise and uneven wear. Unfortunately it can't be shimmed because the deep groove in the gear is allowing the shaft and pin to slide.

I just checked out the heavy duty gear set for the axles and that looks like it would fix the output shaft from sliding in and out. Axial has in the description that it reduces the slop in stock gear set. They are pricey, but at least it is a solution.

Can someone else check their spur to see if it moves back and forth?

Thanks

Hi,

Really sorry to hijack but I started building my Honcho last night and also have a little issue.

The two halves of the diff case front and back aren't flush. The ends of the case where the driveshafts poke out, there about 1/16 gap both ends.

Doesn't seem right to me?

Once you put the carriers on the front and the ends on the rear it will close the gap. I had the sane issue. The case was warped.

Bump

Can someone please try moving your spur assembly back and forth so I can see if it suppose to do this?

Thanks

When i built my axles and transmission, I had the same problem, and axial did not give enough grease to make your gears "water resistant" so my suggestion to anyone who builds a kit, you need to go and get a large tube of multi purpose grease, stuff that is water resistant, and just shovel that grease in there, and after you put it together there is not near as much play, it takes about 10 minutes of working the grease into the gears, and the grease will pour out the outputs and the spur gear area, this is normal and should solve your problem. I have pictures in my build thread of the axle re-build as I thought I gotten rocks or sand inside the axles.

I also wrote this suggestion in another thread of "what you need to build kit" with a few other suggestions you could quickly scan over and get ideas on what you need.

http://www.rccrawler.com/forum/axial-scx-10/316898-first-time-building-kit.html

hope that helps

Thanks for the info. I did use some marine grease I had, but I didn't pack it, so I will try that. As well planned as this kit is and made from quality parts, I find it hard to believe that Axial meant for it to be this way. I sent their support an email to find out why this is happening. I will post back when they respond.

I too noticed some play in my trans input shaft and pinion gears when I assembled my SCX a few weeks ago. I don't remember having these issues when I assembled my AX-10 some years ago.

For the axles I just put a 5mm Teflon washer (I believe it was a Traxxas item) under the pinion before inserting it into the diff case/inner pinion bearing. It holds the gears slightly tighter together, but they don't seem to bind or such. Then I put another washer on the pinion before putting the driveshaft on, slid the driveshaft up against the washer and tightened both setscrews. Seems to be working good cause I have almost ten hours of use on it and they are still fairly tight, with just a tick of in and out play.

To remedy the play in the trans input shaft I had to stack several small 5mm steel washers onto the input shaft just under the drive pin for the slipper. It took some finangling to find the right height so that the slipper nut pulls the slipper driver down over the drive pin and bottoms on the washers, but not so much that it sideloads the input shaft bearings. Now it too has just a tick of play.

I tried shimming the bearings in the case, but it just kept the case halves from coming together because the play is indeed between the drive pins and the slipper driver and upper gear.

Sorry no pictures, but it wasn't too hard, just time consuming.

I was going to try this as well so thanks for the detailed write up. I just can figure out why they made the pin groove in the gears so deep. That is what is causing the play. If the grooves would have been only as deep as the pin diameter, then the bearings would hold the shaft and gear tight. It's strange...

Thats just odd, because I know that there should be a slight little bit of play, and room for grease to flow around the gears, i have over 150 hours of play from when i first built my kit to when i re built the axles and trans, and added grease. If the gears are too tight, you'll wear out the motor because your pushing more than you should. if i'm not mistaken. but i still don't have any play after roughly 20 hours of play since i greased them, and still no play.. and thats no added washers from the kit build.

Here is a video showing how bad the play or slop is in the spur assembly.

http://www.youtube.com/embed/47wYSyCQrVQ

Mine does that too, not quite as bad I don't think. I was kinda worried about it when I first noticed it, but then I just figured it was supposed to be like that. Please let us know what you find out.

After looking at the manual, I see what you are referring to. That much play should not be acceptable. Axial could easily make the notch more shallow in the 20T gear to remedy the situation - I see no way of shimming as you eluded to.

However, is it possible to shim the other pinned connection from the other side to stop shaft play?

I assume some 5mm Kyosho shims would do perfectly here.

Have my kit on order, so I'm following your thread.

mine was roughly that bad, maybe a little less i couldn't tell ya unless i cleaned it up and removed all the grease and its close to that bad, but tons of grease helps with that, till it oozes out of all the ball bearings, and its good protection from rain and water

Okay so it is sounding like this is normal. Now I just need to find out from axial why they would do such a poor job with the design.

Mine does it too. Axial built a tough rig, I've absoulelty beat on mine and have yet to break anything, I'm not going to complain.

I think they might have done this on purpose so that the gears, tranny don't bind up and seize like a piston in an engine? might be a poor comparison lol but would be good to hear from axial that they did it on purpose

All 5 of my Axial spurs have this in/out play on the shaft and no ill effects have ever appeared from this. I think it's safe to say they are all like that. Stop stressing over it and drive the poor thing. :flipoff:

If it bothers you that bad you could throw some 5mm shims between the pin and the bearing of the trans until most of hte play is gone.. Don't want to bind it up with side preload though.

Not stressing, I am just a curious person and like to know why things are the way they are. I checked and shims won't work because the pin groove is too deep, unless you know how to shim the groove. :mrgreen: