Spur question

[Alpinestars199]

Quick question. I have the newest model x 4.6. I keep chewing spur gears. I know my engine hasn't moved cause I've replaced 2 spur gears and the mesh was perfect when I put the new gear on. My question is hpi manual says tighten the spur gear nut "all the way down" then back it off a half turn how much is all the way down? As tight as I can get it by hand or what? If it matters I have hpi aluminum clutch shoes on a stock 17t clutch bell. Thanks for the help!

 

[Alpinestars199]

Btw I have quite a few years experience with savages. So I'm not new to anything here.

 

[rcnut14]

"all the way down" means as tight as you can get it with a wrench/socket( you should NEVER tighten anything by hand. it should always be tight with a screwdriver or drill/driver). the clutch shoes don't matter.

are you 100% positive that your engine mount isn't loose? see if the engine wiggles a bit.

 

[Jam Racing 1]

instead of loosening it 1/2 a turn lock it down tight, tight means the spring fully compressed, when the slipper is loose it generates heat which softens the plastic material and causes it to strip or melt the center out.....
you can also get the RR steel spur and bell combo for about 40 bux and this will help loads to keep the spur intact.....

 

[Alpinestars199]

I was thinking of a steel spur and hardened clutch bell but isn't the plastic spur the weak link in the drive train so nothing else is destroyed? And yes I'm 100% that the engine hasn't moved like I said the mesh is the exact same for the past 2 spurs I replaced meaning a perfect mesh still. Imy thinking I wasn't going tight enough. Because I could definitely loosen the nut pretty easily. I'll try going tighter to what you guys said and get back to ya. Thanks

 

[Jam Racing 1]

http://www.robinsonracing.com/catalog/savage46.html

 

[rcnut14]

the weak link in the driveline should be the slipper, not the gear.

 

[Alpinestars199]

Well I changed out the spur cranked it down and loosened it about a 1/4 turn it's pretty tight but still will slip under a heavy load. Remeshed for the he'll of it and loctite on the engine mount screws that hold it to the engine plate. I'll see if it works all well if not I'll try a steel spur clutch combo. And I also just replaced clutch bell bearings both of them so that's good

 

[francis Labarbara]

Once mine let go it never worked right again. I run it cranked down with steel gearing now withoiut problems. I wonder if slipping makes enough heat to take the tesion out of the slipper spring. It melted the center out of 2 spur gears at 1/4 turn from tight.

 

[Jam Racing 1]

As has been said many many many times, the slipper will still slip when run down tight, but not so much it will melt plastic gears and running it tight has not presented one single problem on my truck ever..... I wish there was a way to omit the slipper altogether anyway, I see no real reason for it to exist.....

 

[olds97_lss]

As has been said many many many times, the slipper will still slip when run down tight, but not so much it will melt plastic gears and running it tight has not presented one single problem on my truck ever..... I wish there was a way to omit the slipper altogether anyway, I see no real reason for it to exist.....

Depends on the engine/gearing/tires/running surface. I had a hell of a time getting mine to not slip.

Started with low low gearing because I used to run pretty weak engines. Then I got an LRP28S3 and after 6-7 tanks, it was clear that I needed taller gearing, so I decreased the spur to 49T and ran with a 15t bell. Still too low, 49/16 was as high as I could go without having it slip with the spring fully compressed... and then 1/4 turn tighter. I tried running 16/47, but it just wouldn't do it so I gave up for a while and ran short gearing. Eventually, I bought a 47T HPI steel spur and ran the spur tighter and it seemed fine. I just recently went up to 17T and it still wheelies on demand with no effort. Going to try 18T in the spring.

As soon as it would slip, I had to take it apart and rough up the slipper pad/slipper plate for it to hold for half a tank, but as soon as I shifted into second gear and went WOT, you could hear it slip. I melted the center out of a couple spurs and that's when I gave up trying to go faster. I eventually got tired of having it top out in RPM's within 30 feet. Sure, second gear wheelies are cool... but tend to cause nasty crashes.