fried my spur gear today,why?

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dirtbasher

dirtbasher

Active Member
Messages
114
hi guys,
i recently installed hpi 3 speed gearbox, hpi polished tuned pipe n change to a new fuel 25% nitro - rapicon. did the installation myself.
played on a hardcore buggy track,not racing jus bashin around. a few things happen:-

1. after playin a few tanks the stock spur gear was damage(see pics)
2. engine temp up to 270 f(mind u my country is very hot)

wer did i go wrong?

thx
 
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Those teeth are melted from heat by the looks of it.
How old are your clutch shoes and springs?
Was your idle too high?
How was your gear mesh set? (tight or loose)
Any loose or broken screws?
 
clutch shoes n springs r only 2 months old. idle was normal. gear mesh was tight. i think my mistake was not checking the gear mesh by running a pcs of paper between the spur n clutch bell. wat do u think?
 
the one thing iwould def check is if the mill plate is bent or cracked as this would cause you to eat up spur gears. and also check the braces thats under the mill plate.
 
since i damage the spur gear shld i get the steel spur gear 47T wit the racing clutch bell 17T?
 
Do NOT get an alloy spur gear until you can find out what the problem is. It will cost you much more to fix next time then $3 -$4.
If you can get a plastic gear to last more than 2 gallons and get really good at setting your mesh, then I might suggest an alloy spur gear.
But I still run plastic in both my trucks and as long as your truck is maintained properly and the mesh is right the plastic ones will last forever.
 
i agree with Oregon that it is not such a good idea to get a metal one until you figure out the problem is or you figure out how to set the mesh right. since i have had my savy which is a couple years i have only stripped one plastic spur. these things last forever if the mesh is set right.
 
The only times I strip a spur gear are:
1)When a screw loosens or falls out.
2)When I crash and my engine moves from something bending or breaking.
I have ran the same plastic spur gear for 3 years on my race Savage and I'm on about a year (and 6 gallons) on my basher.
I do recommend a vented clutch bell though. So if you were going to buy a new one vented is the way to go. The clutch running cooler doesn't have any down sides. The HPI one works great.
 
u guys r right but ive made a mistake n hav bought the hpi steel spur gear.
my bad. wil set it slightly loose mesh by using a pcs of paper folded 3 times in between the gears then lock tight the mount. wil make sure the screws for engine r mount tight n wit thread lock liquid. anymore advise on how to set the mesh?
thx
 
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dirtbasher said:
u guys r right but ive made a mistake n hav bought the hpi steel spur gear.
my bad. wil set it slightly loose mesh by using a pcs of paper folded 3 times in between the gears then lock tight the mount. wil make sure the screws for engine r mount tight n wit thread lock liquid. anymore advise on how to set the mesh?
thx
Click to expand...

dirt, just make sure you use a washer on your engine mount screws so you can crank 'em down good & tight. put 1 finger on the clutchbell & 1 finger on the spur & rock them in opposite directions; you want to feel a very small amount of play between them, like maybe .5 mm.

ive never cooked a plastic spur gear either; but a very experience bud uses only metal & says its more forgiving than plastic & has never had a problem. think i might upgrade when funds allow.
 
frddyj said:
dirt, just make sure you use a washer on your engine mount screws so you can crank 'em down good & tight. put 1 finger on the clutchbell & 1 finger on the spur & rock them in opposite directions; you want to feel a very small amount of play between them, like maybe .5 mm.

ive never cooked a plastic spur gear either; but a very experience bud uses only metal & says its more forgiving than plastic & has never had a problem. think i might upgrade when funds allow.
Click to expand...

wil do as u told.
thx frddyj
 
dirtbasher said:
wil do as u told.
thx frddyj
Click to expand...

my work is done, put washers on the screw engine mount n lock tight, the spur n the clutch bell hav a bit of freeplay. hav to test it tmrw though, is late night ere. hope it work,wish me luck.
some pics of the new steel spur installed. thx guys!
 
dirt that doesnt look like a vented bell? if it isnt don't expect it to last long like maybe 2 or 3 tanks they are too soft to hold up to the steel spur. as for all this hooplah about the spur gear being cheap to replace as it is the give point. WHAT THE HECK IS THE SLIPPER CLUTCH FOR??????????

I have had bent/ cracked engine plates, broken mounts, and have never broke anything or hurt my gear setup. in either truck .
 
mickey said:
dirt that doesnt look like a vented bell? if it isnt don't expect it to last long like maybe 2 or 3 tanks they are too soft to hold up to the steel spur. as for all this hooplah about the spur gear being cheap to replace as it is the give point. WHAT THE HECK IS THE SLIPPER CLUTCH FOR??????????

I have had bent/ cracked engine plates, broken mounts, and have never broke anything or hurt my gear setup. in either truck .
Click to expand...

mick, i could not open the 1st screw on the stock clutch bell. tried every way n failed. the screw is lock permanently. don't know why. getting a new mill in a few days n wil put the vented bell on new mill.
it wil last 2 to 3 tanks? ru sure? then i best not play till new mill comes 🙁
 
mickey said:
dirt that doesnt look like a vented bell? if it isnt don't expect it to last long like maybe 2 or 3 tanks they are too soft to hold up to the steel spur. as for all this hooplah about the spur gear being cheap to replace as it is the give point. WHAT THE HECK IS THE SLIPPER CLUTCH FOR??????????

I have had bent/ cracked engine plates, broken mounts, and have never broke anything or hurt my gear setup. in either truck .
Click to expand...



""WHAT THE HECK IS THE SLIPPER CLUTCH FOR?????????? """
:lmao: this is for the 5th and 6th weak link Mickey.... I gave up on this long ago. :duh:
 
The screw is thread locked on there. If you heat the screw with a lighter the thread lock will break down and you can remove the screw.
dirtbasher - Its a fact that a steel spur gear can get wasted from a bad mesh. The slipper has nothing to do with the mesh of the gears and how long they will last as its located after the power source in the drivetrane.
The slipper is to protect the diffs and transmission from too much engine torque or if the wheels become locked somehow.
Hoopla? rotfl
 
your are right it can get destroyed but it really makes a nasty noise when its wrong so it lets you know. you are right but the slipper is the weak link that is supposed to slip when you have a bad landing or beat it up you shouldnt have to replace a spur when you land wrong. but enough about this we all have our own opinions .
 
I am plastic spur man myself. I do what backwoods does, but only fold it over twice.

*
 
oregonmud said:
The screw is thread locked on there. If you heat the screw with a lighter the thread lock will break down and you can remove the screw.
dirtbasher - Its a fact that a steel spur gear can get wasted from a bad mesh. The slipper has nothing to do with the mesh of the gears and how long they will last as its located after the power source in the drivetrane.
The slipper is to protect the diffs and transmission from too much engine torque or if the wheels become locked somehow.
Hoopla? rotfl
Click to expand...

wil try n heat up the screw.wen i heat the screw would it damage any other parts?
i wont play wit the stock clutch bell as u guys said is to soft.
u all hav been a great help,thx guys!
 
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