Is this pinion gear trashed?

[Saladfingerz]

I have an issue with my 6s outcast exb where when I throttle the car it doesn't seem to move very fast. Maybe walking pace. In reverse it moves normally but when I drive it forward it makes kinda of a grinding sound and just very slowly chugs along. I thought maybe it was a diff and it may still be. But when I was taking stuff apart I kinda noticed the pinion was chewed up a bit. It also seems like the set screw has come loose and the pinion moves back and forth. Could my problem be this pinion gear? BTW I have only owned the car for approximately 2 weeks.

 

[Diem Turner]

That's pretty chewed up. I would definitely replace it if it were me. The fact that the set screw has come loose probably hasn't helped in the matter and I'm fairly certain that the pinion is the source of the grinding sound you're describing.

 

[Sandracer_NL]

Yep new pinion. Looks like the wear on the pinion is at an angle. Had that before to a lesser degree and tried to run it again, but due to to the angle there is force on the pinion wanting it to slide either forward or backward. Result was that pinion came loose quickly again. New pinion, locktite, let it cure for 24/48 hours and solved.
Your spur gear looks to be OK, but have a closer look because if its’ teeth also show similar wear. If so it might be worth replacing that as well otherwise your new pinion will have the same problem again within a couple of runs.

 

[Hector_Fisher]

Pinion looks like it's been filed down due to grinding from sand or dirt. Happened to me a few times on other trucks.

Did you grease your pinion and spur? It looks like muddy/dirty grease was flung all over. Grease would attract and accelerate tooth decay (can we call that cavities???).

Spur is likely not as worse off because it rotates like ~1/4th as much as the pinion does, so the teeth have just had less contact time.

 

[Saladfingerz]

That's pretty chewed up. I would definitely replace it if it were me. The fact that the set screw has come loose probably hasn't helped in the matter and I'm fairly certain that the pinion is the source of the grinding sound you're describing.

Well after some tearing apart the pinion gear may have been the grinding sound but the fact the car wasn't moving was because of the pin that holds in the left outdrive to the front diff was sheared.

Pinion looks like it's been filed down due to grinding from sand or dirt. Happened to me a few times on other trucks.

Did you grease your pinion and spur? It looks like muddy/dirty grease was flung all over. Grease would attract and accelerate tooth decay (can we call that cavities???).

Spur is likely not as worse off because it rotates like ~1/4th as much as the pinion does, so the teeth have just had less contact time.

No I'm pretty sure my center diff is leaking fluid. So that's where the oil is coming from. My other issue of the car not moving fast I found is because the pin that holds the left out drive on my front diff is sheared off. Or at least I'm pretty sure that's why it's not working right.

Yep new pinion. Looks like the wear on the pinion is at an angle. Had that before to a lesser degree and tried to run it again, but due to to the angle there is force on the pinion wanting it to slide either forward or backward. Result was that pinion came loose quickly again. New pinion, locktite, let it cure for 24/48 hours and solved.
Your spur gear looks to be OK, but have a closer look because if its’ teeth also show similar wear. If so it might be worth replacing that as well otherwise your new pinion will have the same problem again within a couple of runs.

The spur looks almost brand new still so I think that's ok.

 

[Diem Turner]

Well after some tearing apart the pinion gear may have been the grinding sound but the fact the car wasn't moving was because of the pin that holds in the left outdrive to the front diff was sheared.

Yeah, that makes sense. I've had that happen once or twice and I've broken a planetary gear in half doing drag hits. I wouldn't have thought it possible but I actually repaired the broken planetary gear by affixing a 0.2mm carbon fiber disc to the back of it with JB Weld and it worked just fine. For driving anyways. I didn't try any drag hits with a glued gear, lol.