SCX10 Transmission Noise/Output Shaft Wobble

[CHawk68462]

I'm in the process of doing a pretty significant rebuild on my SCX10. Prior to starting, I had some kind of mechanical failure. I was out on a trail and whenever I went to climb or put power down the truck would make a loud grinding noise and all 4 wheels stopped turning.

So far I've had every single component of the driveline apart. Nothing was stripped or loose. No teeth missing either. I lubed everything for the reinstall.

Yesterday I got the truck rolling again and this is what I've got:

-A distinct wobble at both output shafts on the transmission
-An extremely noisy transmission and/or meshing at the spur

I'm pretty concerned with both of these issues. The wobble makes me think I've bent something. Part of my rebuild involved getting new axle shafts (I installed GCM Metalhead axle housings,) and I noticed that one of the rears was distinctly bent.

Anybody experience this before? I'll be troubleshooting, but any advice will be greatly appreciated.

[uclabruins89]

I haven't experienced this, but I know Robinson Racing makes a 1 piece steel outdrive gear (the whole bottom gear is 1 piece of steel, no more screwing the outdrives into the gear. That would probably solve the wobble if that actual part is bent.

Take the motor off and see if the tranny itself is noisy. I've had a noisy mesh before because the motor/pinion was too close to the spur, basically I had a bad mesh setting.

[Ramination]

One time I had the outputs wiggling and two of the three little screws that hold the outdrives to the gear had backed out. Easy fix with some Lock Tight, or get the one piece gear like mentioned above (I have that piece in another rig and is great). Also, did you replace all the bearings in the transmission? That could be contributing to your noise and wobble.

[CHawk68462]

I wonder if my LHS carries those bearings. I may throw a set at it just to see if the wobble goes away. It can't be good for the entire driveline : /

Thanks for the tip.

[CHawk68462]

I just bought a full set of SCX10 bearings from Fast Eddy. I probably should have done that in the first place considering how much I tore this machine down throughout my build.

[Lentsnh2012]

Originally Posted by CHawk68462

I wonder if my LHS carries those bearings. I may throw a set at it just to see if the wobble goes away. It can't be good for the entire driveline : /

Thanks for the tip.

Traxxas Bearings will pop right in. But yeah take the trans out of the truck and spin it by hand and see if there are any hard spots or bad gear mesh.

[CHawk68462]

I know (from the build) that there are rough spots in all rotating components (both axles and the trans,) so would you think that's a sign of borked bearings? I had no idea I was being so hard on this thing.

[Lentsnh2012]

Originally Posted by CHawk68462

I know (from the build) that there are rough spots in all rotating components (both axles and the trans,) so would you think that's a sign of borked bearings? I had no idea I was being so hard on this thing.

A lot of it could be from the molds for the plastic.

While you're in the transmission, I would just get all new gears to stop all of that bad gear(s) nonsense. It would be hard to hurt those bearings unless you just flat out installed it wrong or you put some serious abuse to it. Being that I had a 6900Kv Castle system going through my Wraith with stock bearings, I highly doubt you hurt the bearings. Also, watch how much grease you put into the trans. I only coat the bottom gear in grease and then rotate the trans by hand until all of the gears have a little grease on them and call it good.

Hot Racing has a full set, Axial has a full set and you also can't go wrong with RRP gears. It is just up to your wallet on how much you want to spend on new steel gears.

[boohoo]

Originally Posted by CHawk68462

I'm in the process of doing a pretty significant rebuild on my SCX10. Prior to starting, I had some kind of mechanical failure. I was out on a trail and whenever I went to climb or put power down the truck would make a loud grinding noise and all 4 wheels stopped turning.

So far I've had every single component of the driveline apart. Nothing was stripped or loose. No teeth missing either. I lubed everything for the reinstall.

Yesterday I got the truck rolling again and this is what I've got:

-A distinct wobble at both output shafts on the transmission
-An extremely noisy transmission and/or meshing at the spur

I'm pretty concerned with both of these issues. The wobble makes me think I've bent something. Part of my rebuild involved getting new axle shafts (I installed GCM Metalhead axle housings,) and I noticed that one of the rears was distinctly bent.

Anybody experience this before? I'll be troubleshooting, but any advice will be greatly appreciated.

i had roughly the same thing happen when the truck just stopped for no reason. i found out it was the idler gear had worn down and like you said there was no reall damage to see no missing teeth or that so i fitted a new one and its running fine now. as for the noise comeing from what you think is the spur could be a wierd pinion gear noise i bought a 20t one and put it on and all i got was a noise coming from the gearbox so i tried a 19t of a differnet comany and no more noise so it could be worth trying a different pinion

here is the noise mine made when i ran the 20t

noisey scx10 transmission steel gears fitted - YouTube

[Natedog]

Originally Posted by boohoo

i had roughly the same thing happen when the truck just stopped for no reason. i found out it was the idler gear had worn down and like you said there was no reall damage to see no missing teeth or that so i fitted a new one and its running fine now. as for the noise comeing from what you think is the spur could be a wierd pinion gear noise i bought a 20t one and put it on and all i got was a noise coming from the gearbox so i tried a 19t of a differnet comany and no more noise so it could be worth trying a different pinion

here is the noise mine made when i ran the 20t

noisey scx10 transmission steel gears fitted - YouTube

Which brand steel gears and what grease did you use?

[Phippy]

I have Robinson Racing gears in mine. They're great. Trans is greased with Lucas X-Tra Duty (1:1) wheel bearing grease. Best thing I've found for rc to date!

Working at an auto parts store is a good problem to have sometimes!

[CHawk68462]

So, I didn't figure out some of the wobble, but I did make a strange discovery.

The slipper clutch unit is causing the spur gear to wobble. Is this normal?

[meatmonkey]

No, the spur and slipper should not "wobble". If it truly wobbles then likely you have a defective spur, or the three bolts holding it to the slipper plate are not evenly torqued.

With how imprecise Axials molds have become it is very common to have excessive side-to-side slop in the top shaft though. Enough to allow the spur to walk halfway off the pinion. A handful of 5x7x.2mm washers underneath the slipper plate will take the slop out.

Have you actually torn the trans apart to see if the bolts holding the output shafts to the lower gear have loosened up? Virtually every RTR Axial I have seen suffers from this eventually. One of the MANY reasons I will only purchase kits.

For anyone paying attention: Axial bearings suck, so do Traxxas and Duratrax bearings. Avid's or Fast Eddies are the best for the money.

[CHawk68462]

Neither the shaft or the spur have wobble. It's all in the slipper clutch. I did check the output shaft gear screws and they're just fine.

I'll mess with the torque on the spur, but at this point I know part of my issue is that clutch. I've already got a set of fast eddy bearings on the way. Anything else I can throw in there just to tighten things up. I'm still stumped on the output shaft wobble though. : /

[DaJester]

My girl's practically new SCX10 started doing the same thing yesterday, the output shaft seems to be wobbling causing a wah wah sound when running it. Gonna go back and tear down the tranny and take a close look.

[Biomedchad]

Anyone figure this out yet? My shaft wobbles too! Replaced the shaft and clutch with a slipper eliminator kit that includes a new shaft and I still have a wobble. From shaft all the way through to the wheels. Seems like a lot of people have this issue but nobody ever says I tried this soccer or this shaft and it worked. I have new bearings coming tomorrow. That's the last thing it could be I guess.

[ROLANDROCKSHOP]

I think someone tried an extra bearing on the top shaft and it stopped a lot of the slop at the clutch/spur.

cant remember who it was or where they posted..

[pickled]

I purchased the GPM metal trans gears and they work great no noise what so ever 1 piece input gear and shaft and 1 piece output the input/spur shaft fits the slipper clutch perfectly with no play!


link eBay GPM SCX10 metal trans gears

[Biomedchad]

I'm absolutely floored by this. I've got new avid bearings, axial steel gears and the same wobble. I've even tried the slipper elimination kit. Basically, it comes down to the poor mold of the transmission case I think. The gears just wiggle all over inside there. Nothing snaps into place. My slash, as poor quality as it is, has taken every upgrade and came out better. Axial has sent me parts and more are on the way. They will get more of my mind Monday for sure. I'd send the kit back but I've modded things and waterproofed. I may order this kit that was linked.


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[daltrey]

Maybe this video will help. http://m.youtube.com/watch?v=acrSdzzniiw