Before I start opening things up... any input?

[high plains drifter]

So besides the servo finally calling it quits last week, I've run into something that has me stumped. I experienced today, something new:

A noise that seems to be coming from the motor or front differential area but not 100% sure. The noise is like you might hear when a tire is rotating and contacting a fender or maybe as if a small stick was stuck and contacting a drive-shaft... but it's neither of those.

Vehicle had only been running for a couple hundred feet in very mild conditions... no mud, no water, nothing causing undue stress to drive-line components nor motor. Lockers had been engaged prior to this noise but were not engaged at the time that the noise started.

Prior to the noise, I noticed while driving, that during full lock left and right... that the front wheels seemed to be "hopping"... something that has not happened before. Also... the last time that I ran the vehicle a few days ago, it wasn't having any apparent issues.

Possibly worth noting... Just last night, I had pulled the front passenger side axle shaft out because of some dried grass that had recently worked it's way into the axle housing. I wanted to clean it out so I removed the shaft, cleaned out the tube, and reinstalled everything. I also recently re-torqued my bead-lock screws although tires look to be seated just fine as they were already.

So... she's hopping a little in the front end while turning left and right. And there is some kind of seeming rotational noise coming from the front end of the vehicle. The noise subsided but still exists as does the hop. I'm not seeing how the two might be connected but I wanted to mention it since both issues occurred around the same time.

So before I try to troubleshoot... does this sound like a familiar problem? Anything specifically to look for besides looking for damage to gear-teeth and making sure that front locker is engaging properly?

[high plains drifter]

This is what it looks like inside... Not good, right? Cause? Solution? Also a lot more grease on the inside of the diff cover than when I pulled it off a few weeks ago to paint it. Wondering if maybe when I reinstalled the pass side axle shaft last night, that I might have not gotten it seated correctly? I'm guessing this is a seal that may now need replaced? Thanks for any help.

[magic_yeti]

Did you set the endpoints for the new steering servo?
Check if the tires are rubbing somewhere if you steer left/right.

[high plains drifter]

I did not set epa for the new servo. Tires are not contacting any part of the chassis nor inner fender wells while servo is fully cycled left/ right. I didn't consider that the lack of limiting end-point travel could be causing the wheel hop during full lock but I'll have to look into how to set epa and see if that's the issue. Still using stock esc fwiw. Thank you, magic_yeti.

Would still like to see what y'all say regarding that diff.

[33m]

Have you ran it without the body to help pinpoint the source of the noise? Did you adjust your diff lock servo's so the over throw is about equal in each direction?
So you have a new steering servo? Are you still using the stock servo horn?

[Stewdog]

I feel like I must be missing something...? The diff looks normal to me. What do you see that looks not good?
The grease on the diff cover is totally normal and is just what slings off the gear as it's running at higher speeds.

[high plains drifter]

Stewdog- It's the section that I'm pointing to in these pics. It looks like the plastic piece ( I originally thought that was rubber) is warped or pushed out of the groove. So... if it doesn't look like anything's out of place, then I'm back to wondering what's causing this clicking noise.

I should also have mentioned that the noise doesn't seem to fluctuate while turning left or right. The noise occurs when you give it throttle... wheels straight or turned doesn't change the sound.

Only reason I wondered about the grease is because last time I had it opened up, there wasn't that much slung everywhere. I figured it was normal over time but just wanted to mention it in case it appeared suspect.

33m- Yep... ran it without the body. Held it and ran it off the ground also. Noise seemed to be coming from the front end. It's quieted down some but the clicking is still present regardless of wheels turned left or right.

I've never adjusted anything on the stock diff-lock servo's. I've watched and listened to them engage/ disengage and all seems to be good there... throw appears to be equal both sides. Tbh the horror stories about how delicate those servos and savers apparently are, have kept me from messing with them. I don't want to screw those up as long as they're operating correctly, which they seem to be doing.

Still using the stock horn although it's fine and seated properly on the servo output shaft. Also it's the correct size... solid fit. So I know that the horn itself doesn't have anything to do with it.





EDIT> I have EPA adjustment units that I received from HeyOk. I originally got two of them to set the epa's on the mini locker servos but if those units can be used for a larger steering servo, I may use one of them.

[Summitonslingrs]

Originally Posted by high plains drifter

Stewdog- It's the section that I'm pointing to in these pics. It looks like the plastic piece ( I originally thought that was rubber) is warped or pushed out of the groove.

High Plains Drifter, The metal piece you point to is the locker. That black plastic is the locker actuator. When the locker cable is pulled it pivots. There are two tabs on that black piece, when it pivots the tabs slide the locker into the diff cup.

Everything looks normal to me.

[Natedog]

Looks fine from here. Check that front driveshaft yokes are in phase and if they are good, then check ring and pinion gears are not chipped.

[high plains drifter]

Will do Nate. On to the driveshafts and r&p. Thank you guys so much. I just hate when there's an abnormality and I can't find it... even if it's a noise that comes and goes, I want to identify it.

Again.. Thanks so much.

[Summitonslingrs]

Seems like I remember the same noise you are describing and it was the motor pinon set screw hitting the inside of the cover...? This was after I realigned the half ass mesh from the factory.

[cmbscx10]

Sounds like playing card in your spokes it's the pinion as suggested.

Sounds like a lunchbox locker while turning then Shoulda bought a Losi. Jk Jk.

I've read a lot of reviews and watched a ton of YT reviews and running vids. I don't recall anyone grenading the stock gears even with BL power. If true that is a hats off to Traxxas. My Axial SCX and wraiths R&P's lasted all of 5 packs before they gave up and 2 packs for the AX trans. That was all on stock electronics too.

[OSRC]

There are guys doing 6S backflips on Youtube. That's crazy....

I've had small bits of debris get stuck in the grease on the gears and it makes a clicking sound when the gears are turning. Happens especially with my Tamiyas since they tend to have 3 times more gears than needed. Very easy to miss..and very annoying. If I have a clicking sound like that, I use a hobby knife and clean out between the gear teeth. I don't always find whatever it is, but usually it solves the clicking.

[high plains drifter]

It does sound VERY similar to the ol' "playing cards in the spokes" so if I don't find any discrepancies with the drive-shafts then I'll be checking the motor at that point. Not sure exactly how to go about checking the motor/ set-screw although I assume that I will need to pull it out of the vehicle and remove the cover ( can?).

This is going to sound really dumb but my experience with r&p's is in the differential of full-size vehicles. Assuming that my trx4 issue might be with the motor pinion/ spur mesh, are there any recommendations how to go about checking things out? I'm assuming that in order to check the set-screw and pinion/ spur mesh that I will have to pull the motor out of the vehicle? Also I assume that correct mesh can be determined by using strip of notebook paper... yes?

Anyway... Still familiarizing myself with this rig and since it was an RTR, it's taking me a little more time to understand what parts might be creating issues and how to go about confirming, replacing, etc.

I genuinely appreciate the patience and assistance of those trying to help me resolve this.