Stock spur gear issues

[DealBreaker]

My savage truck is only about 11 tanks into its life, about the 10 tank in I stripped the stock spur... Did some research and concluded a stock gear was the best replacement part, but buy more than 1 as they do tend to strip over time. After much conversation within the forums and reading the liturture that came with the truck I felt confident with installation. (Correct gear mesh with sheet of paper, and tighten spur nut completley and backing off 1/4 turn)... 2/3rds into the 11th tank and stripped the new spur!! WTH????

Do you have to drive these trucks easy? IE: Glorified granny car?? Truck is all stock with the exception on Itegy suspension and I've got it running pretty rich. I have a hard time believing its making TOOOO much power for the drive terrain...

Dose Catapilar make a spur gear?

 

[Extreme RC Mods]

Do you have any pictures of the spur gears? I have a few idea's but the pictures will tell the story.

 

[savage ray]

I've replaced two in my savy x also . After the second I went with a RRP steel racing spur and clutch bell, so far so good ! Good luck ! The second plastic spur was my fault, I forgot to put the brass bushing in it from the original. Lol

 

[DealBreaker]

Do you have any pictures of the spur gears? I have a few idea's but the pictures will tell the story.

Just took the pics, The gear is still on the car so if need be ill take it off but here ya go...

 

[bgbdwlf2500]

its bad mesh from the factory, mine did it too (on the first non break in tank running very rich). I put a 49 on it and have had no problems with mesh since then. I wanted the stock 47 but they didnt have one in stock

 

[Extreme RC Mods]

That looks like heat is causing the issue, the middle and right pics look as though the mesh was only grabbing half the gears. If your idle is too high or your shoes are dragging, they will build heat into the clutch bell. When the truck is not moving, the heat will transfer from the bell to the teeth on the spur gear. Once the teeth on the SG get hot, they get soft and often the next time you hammer the throttle it will hit that hot spot and start shredding gears. If the SG was to fail, then the teeth would be ripped right from it, your pictures don't look like this is the case, rather the heating issue I just mentioned and lack of proper mesh. Try to lower your idle so the shoes stop rubbing and also drive off slow for a few seconds after just sitting there and give the SG a chance to cool off.

 

[bgbdwlf2500]

That looks like heat is causing the issue, the middle and right pics look as though the mesh was only grabbing half the gears. If your idle is too high or your shoes are dragging, they will build heat into the clutch bell. When the truck is not moving, the heat will transfer from the bell to the teeth on the spur gear. Once the teeth on the SG get hot, they get soft and often the next time you hammer the throttle it will hit that hot spot and start shredding gears. If the SG was to fail, then the teeth would be ripped right from it, your pictures don't look like this is the case, rather the heating issue I just mentioned and lack of proper mesh. Try to lower your idle so the shoes stop rubbing and also drive off slow for a few seconds after just sitting there and give the SG a chance to cool off.

I didnt notice that til you mentioned it. It does look like it only took out a few teeth. When mine did it, it took all of the teeth of the spur

 

[olds97_lss]

I think he's talking about the fact that part of the teeth that are ground off still remains. Means you need to shim your flywheel/bell forward a mm or two. Then you get full contact of bell to spur teeth.

How you drive also matters. The slipper is designed to slip under extreme situations, but is not a replacement for good driving habits. Jumping and landing while on the gas will shear a spurs teeth right off. The slipper takes some of that out of it, but repeated "on power" landings will either blow the spur, snap an axle or blow a diff. Out of the 3, the spur is the cheapest. I'm not saying that's what your doing, just saying it as something to be mindful off.

I don't use the paper method, but I've been running RC's and working with things that have gears with adjustable mesh for many years. I just adjust it until the spur/bell spin smoothly and there is a "tick" of play if you hold the bell still with a screw driver and rock the spur back and forth.

Also, having the engine as close to parallel with the chassis matters too. If you have mesh that feels right, looks right but the engine is crooked, it will shear the teeth off very easily.

I've beat the snot out of my savage and I still have my first 52T spur gear. It has 10+ gallons of use on it. The teeth are chipped all to heck on it from rocks and debris hitting it, but it's still usable.

Running a steel spur isn't usually necessary and will sometimes just move a problem on to more expensive parts.

 

[Extreme RC Mods]

Good info right there, I run a locked spur gear due to the engines I run, the slipper doesn't stand a chance if it can spin even just a bit, but I run plastic spurs 100% in my savages. You can see at about 7:00 where there was a hot spot as the teeth ripped off deeper then the rest, but that's all it takes.

A little cheaper then replacing these using a steel spur gear.....