I was just screwing around today with my daughter, we were playing with her b4.1 FT, and everything was going nice and smooth, until about halfway though the first run she hit a jump *pretty small maybe 1~2ft* and when she landed the rear-end started making this loud crunching sound. I brought it home, and took it apart. The spur gear *AE 48p 81t* was unevenly worn, and the loud sound was when the spur gear rotates and it goes from good mesh to loose. I took the whole rear-end apart, and cleaned it up. Inspected the diff, idler, etc and everything looks fine.

I was just wondering what would cause this.

Her setup is RS Pro, 2s LiPo, 23/81, Orion 10.5T brushless. When she is driving, I have travel limited to 40% Forward, and 50% Reverse.

Thanks

When she landed it might have hit the rear motor guard pretty hard, knocking the motor out of proper mesh. might have made the mesh tighter. The stock AE spur gears are not that great and usually out of round. reset the mesh and then try it. I use Kimbrough spur gears.

I'm assuming its a stock AE spur gear. Their quality control on those leaves quite a bit to be desired. You probably had a good mesh set on the spur and the motor moved a bit when you hit the jump. Some of the gears are pretty egg shaped. I've used their spurs from day 1 and some are smooth and some are noisy. I've heard Kimbrough gears are quite a bit better. Also, make sure when you get the mesh set to check it all the way around the spur and then make sure the motor screws are good and tight.

Thanks, and yes it was the stock AE spur gear.

I just pulled that spur gear, I spent at least 20 minutes trying to get it to mesh correctly again. The fix to keep that from happening in the future is just to locktite the motor screws? Also, when setting mesh, I just eye it all the way around. I normally do 2 to 3 rotations of the spur just to be on the safe side. I heard that the old paper mesh is still good, is that true?

Kimbrough makes the AE gears guys.

They are different. I have a stack of AE packaged spur gears, and they are all semi out-of-round, and they are all very noisy. A month ago or so I picked up an actual Kimbrough packaged spur gear... it looks similar, but is definitely different. It's perfectly round, and my car is wisper quite around the track with it. Night and day difference.

Ae spur gears are round,.


Don't get confused by
those who have a bent motor plate or a bent top shaft still insisting that its their spur gear that out of of round ....

I have known Jay Kimbrough for 20 years guys...He has made the AE cars and truck gears since before there were even dual plate/pad slippers. Running different brand pinion types can cause the car to be loud too. What boggles my mind is reading posts about being "out of round'. My stock AE spur gears do not have "high and low" spots, nor do they wobble from side to side.

A bent motor plate I can see happening, but how would you go about getting a bent top shaft? I fully disassembled everything after the loud noise crunching noise began, the only thing that I seen was that my spur gear had an uneven mesh. That being said when I installed it, it was fine (or at least fine enough for me not to know the difference). When I put in a replacement spur, everything meshes back up fine again.

How much of the T4 chassis are you guys cutting?, Was it 11.1mm?
Thanks

yeah... but don't worry about the .1... Just cut 11, and you will end up taking off the tiniest bit more to sand it perfectly straight to get a proper seam.

Land on the tail end , hit the motor & motor moves bending the top shaft & motor plate ..


If Ae spur gears were out of round ?

All would be , not just a few ....


There not though, just a few who think they are , when they really have a bent top shaft or motor plate ...

Kimbrough makes AE spurs = YES

SOME AE spurs are out of round = YES

If you purchase a AE spur and a Kimbrough spur they will look exactly the same = NO

Wild Cherry says everyone's shaft is bent so he can feel "normal" = YES

This is an old issue. I know for a fact that there are people on here who run Kim. spurs based on my posts as such. They all seem to be happy with Kim. spurs vs. AE......

post #1573 +/- a couple pages, post #3134 +/- a couple pages....

must be a lot of guys with bent shafts out there...

You are saying Ae spurs are out of round ....


yet


My Ae spurs that I use are round and true ....

Just check out any of my Ae Rides anytime, they are all nice & quite......



Ae spur gears on Wild everyone ....