Gear grinding or shaving?

[ChuenouXiao]

Hey all you helpful Racers out there!


I notice my XB car wouldn't go forward smoothly when pushing with my hand, in fact it would lock in place. What went through my head was the gear is grinding. I took the engine off to look at the gear mesh and found out that the gear providing power to the dog bones is shaving the smaller gear off. Here is a pix. Note my XB is pretty new and have only gone through around 15 tanks only. I don't do hops or off road or reckless acceleration. I do reeve the engine during high speed run to hear the exhaust but that shouldn't be enough to damage my steel gears. Tell me is this normal? Am I the only one experiencing this? Tips and suggestion to fix this? Hop up? How to stop this from happening? (Note that this pix below is when I've already cleaned the shaving of the steel gears from the chassis floor.) Your help is very much appreciated.

 

[Deluge]

Ouch. Check the bearings for slop. A bad bearing will cause gear mesh issues.

 

[ChuenouXiao]

Hey all you helpful Racers out there!I notice my XB car wouldn't go forward smoothly when pushing with my hand. in fact it would lock in place. What went through my head was the gear is grinding. I took the engine off to look at the gear mesh and found out that the gear providing power to the dog bones is shaving the smaller gear off. Here is a pix. Note my XB is pretty new and have only gone through around 15 tanks only. I don't do hops or off road or reckless acceleration. I do reeve the engine during high speed run to hear the exhaust but that shouldn't be enough to damage my steel gears. Tell me is this normal? Am I the only one experiencing this? Tips and suggestion to fix this? Hop up? How to stop this from happening? (Note that this pix below is when I've already cleaned the shaving of the steel gears from the chassis floor.) Your help is very much appreciated.

Here is another pix before I clean the steel shavings.

 

[ChuenouXiao]

Ouch. Check the bearings for slop. A bad bearing will cause gear mesh issues.

Sorry I am kinda noob. Bearing? The gear that is connected to the fly wheel? It does look like the small gear connected to the flywheel is shaving off and is not as sharp and crisp as it use to be.

 

[ChuenouXiao]

Ouch. Check the bearings for slop. A bad bearing will cause gear mesh issues.

I see what you mean, the bearing holding the bad gear that is being shaved off could have a wobbly bearing or vise versa on the gear making contact with the bad gear?

 

[Deluge]

Yes. The gear shafts ride on bearings. If you have a bad bearing, it'll throw the gear mesh out of whack.

 

[ChuenouXiao]

Yes. The gear shafts ride on bearings. If you have a bad bearing, it'll throw the gear mesh out of whack.

Ok, with my engine out and me seeing how the gears are spinning freely... how do I know figure out which one has bad bearing? I notice the big fly wheel is wobbly on its shaft.... don't know if this is normal. The smaller gear that is shaving off seems to be stable. How do I figure out which bearing is bad on which gear for sure? I'm assuming its the design of the fly wheel in which its space just a little too far from the other gear causing it to shave?

 

[Deluge]

I'm assuming you're talking about the larger gear. If it's wobbly, check the screws. There are four screws that hold the gear onto the shaft, make sure they're not loose.

Here's a link to the manual. The center gear assembly is on page 6 at the bottom.

Rampage XB & XT Parts Manual

 

[DemonRC]

Since you said the "big flywheel" is wobbling I'm assumining you mean the big crown gear that is connected to the small pinion gear that is getting torn up. I've had this happen twice and here are the 2 reasons for it happening:1) The 4 bolts holding the big crown gear to the center shaft came loose and the gear wobbled just like yours. 2) I had a bearing fall apart and the gear mesh went bad causing me to destroy both the crown gear and the pinion gear.Check the drawings I've attached for locations of these bearings and bolts.









/monthly_2011_11/1.jpg.82ffdd1162bff9115be48224b23efdb1.jpg

/monthly_2011_11/2.jpg.86a41a7fcd6a6d17785527515143e61e.jpg

 

[ChuenouXiao]

I'm assuming you're talking about the larger gear. If it's wobbly, check the screws. There are four screws that hold the gear onto the shaft, make sure they're not loose.Here's a link to the manual. The center gear assembly is on page 6 at the bottom.

Rampage XB & XT Parts Manual

WOW!!!!!!!!!!!!!!! Thank you so much buddy!..... This manual is better then the one that came with my XB! How do I add you as friend in here?

 

[ChuenouXiao]

Since you said the "big flywheel" is wobbling I'm assumining you mean the big crown gear that is connected to the small pinion gear that is getting torn up. I've had this happen twice and here are the 2 reasons for it happening:1) The 4 bolts holding the big crown gear to the center shaft came loose and the gear wobbled just like yours.

2) I had a bearing fall apart and the gear mesh went bad causing me to destroy both the crown gear and the pinion gear.

Check the drawings I've attached for locations of these bearings and bolts.

THANK YOU SO MUCH FOR RESPONDING! ARE YOU THE FAMOUSE DEMON? THE ONE WHO IS MAKING THE PULLEY AND 2 SPEED FOR THE XB? About my wobbly gear.... will check on my bearings and the big fly wheel screws.

 

[ChuenouXiao]

Since you said the "big flywheel" is wobbling I'm assumining you mean the big crown gear that is connected to the small pinion gear that is getting torn up. I've had this happen twice and here are the 2 reasons for it happening:1) The 4 bolts holding the big crown gear to the center shaft came loose and the gear wobbled just like yours.

2) I had a bearing fall apart and the gear mesh went bad causing me to destroy both the crown gear and the pinion gear.

Check the drawings I've attached for locations of these bearings and bolts.

So Demon in this situation do you recommend me replace both gear? The small one for sure, but the bigger one have very small shaving. I'm afraid keeping the big one will cause future problem. What are your thoughts? What should I order too along with my gears? Some extra bearings? Screws for the gears that I order? Should I loctite the screws to my big fly wheel?

 

[ChuenouXiao]

I'm assuming you're talking about the larger gear. If it's wobbly, check the screws. There are four screws that hold the gear onto the shaft, make sure they're not loose.Here's a link to the manual. The center gear assembly is on page 6 at the bottom.

Rampage XB & XT Parts Manual

So in this situation do you recommend me replace both gear? The small one for sure, but the bigger one have very small shaving. I'm afraid keeping the big one will cause future problem. What are your thoughts? What should I order too along with my gears? Some extra bearings? Screws for the gears that I order? Should I loctite the screws to my big fly wheel?

 

[Deluge]

I'd replace both. If the screws were the issue, just replace the gears. You can reuse the screws. And yes, you need to loctite them. Use blue loctite.

Pinion Gear

Diff. Gear

 

[ChuenouXiao]

i'd replace both. If the screws were the issue, just replace the gears. You can reuse the screws. And yes, you need to loctite them. Use blue loctite.pinion gear

diff. Gear

thank you so much!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! I know i sound kinda wierd but i want to say i love all you people who are helping me out!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

[ChuenouXiao]

I'd replace both. If the screws were the issue, just replace the gears. You can reuse the screws. And yes, you need to loctite them. Use blue loctite.Pinion Gear

Diff. Gear

Is there any way to make sure the bearing does not fall apart, pop out or damage?

 

[ChuenouXiao]

Since you said the "big flywheel" is wobbling I'm assumining you mean the big crown gear that is connected to the small pinion gear that is getting torn up. I've had this happen twice and here are the 2 reasons for it happening:1) The 4 bolts holding the big crown gear to the center shaft came loose and the gear wobbled just like yours.

2) I had a bearing fall apart and the gear mesh went bad causing me to destroy both the crown gear and the pinion gear.

Check the drawings I've attached for locations of these bearings and bolts.

Is there any way to make sure the bearing does not fall apart, pop out or damage?

 

[DemonRC]

So in this situation do you recommend me replace both gear? The small one for sure, but the bigger one have very small shaving. I'm afraid keeping the big one will cause future problem. What are your thoughts? What should I order too along with my gears? Some extra bearings? Screws for the gears that I order? Should I loctite the screws to my big fly wheel?

Take a closeer picture of the big crown gear and the small pinion gear for us to see. We could then give you a better guess on whether you should replace them or not. Also, I've used longer bolts in the big crown gear and put nuts on the other side so that it will never come loose again.

Also, you asked if I was the one making the 2 speed. Yes I am. I'll take more credit for it once I actually get it into a customer's hands

 

[Guest]

+1

Awesome explanation and diagram! Very resourceful!

 

[ChuenouXiao]

Take a closeer picture of the big crown gear and the small pinion gear for us to see. We could then give you a better guess on whether you should replace them or not. Also, I've used longer bolts in the big crown gear and put nuts on the other side so that it will never come loose again.Also, you asked if I was the one making the 2 speed. Yes I am. I'll take more credit for it once I actually get it into a customer's hands

Demon I think I'm going to replace both gears to save future head ache. The crown gear seems to have a little shaving only but its one of those thing where I want to do it once and do it right the first time. I know for sure the pinion gear needs to be replace cause the teeth are not very sharp anymore.