baja clutchbell screw??
 

i melted my clutch bell mount thingy where the bearings are housed..... there're plastic!!!

anyways the bolt that holds the pinion onto the bell also broke off
i remember seeing a post (i think) on the easiest way to get the remainder of the bolt out.... can anyone direct me to it, i cant find it anywhere....

and how different would it be to drilling a small hole down the bolt and using "easy out" to screw it out?? or drill a larger hole and re-tap a larger thread?

cheers
Ryan

RE: baja clutchbell screw??
 

The clutch bell holder you can replace with a allot one pretty cheap.
You can drill into the center of the bolt if it's flush and you can't get ahold of it with vice grips to spin it out, mine when it broke came right out really easy. I'd call HPI if it's a new baja they'll warranty everything damaged.

RE: baja clutchbell screw??
 

thanx badz
yes im already eyeing up an alloy one... have to get clutchbell bearings too. parts of the outter bearing are melted into the plastic bracket lol

ive already emailed hpi about my dogbones with which they sent me out new ones..... if i email bout this they probably send out another plastic one...... alloy one is cheap enough

the broken bolt is flush with the shaft so i cant get grips on it....will have to drill hole and work it out

cheers
Ryan

RE: baja clutchbell screw??
 

Ask HPI to toss you a set of bearings too, they should, when my clutch bell screw broke they sent me the clutch bell,screw and new spur and pinion gears

RE: baja clutchbell screw??
 

can you make two claims? ive already claimed on dogbones (3 months ago)

RE: baja clutchbell screw??
 

Don't know but it is worth a shot

RE: baja clutchbell screw??
 

If you have a dremmel put a small cut in the broken screw and use a small flat blade screw driver to screw it through like your tighting it. replace with a longer screw next time so you can get ahold of it from the inside of the clutchbell to twist it out. Also if you used threadlock heat the area up first to release the loctight

RE: baja clutchbell screw??
 

Try to drill it out from the backside, the end of the screw is usually "cupped" from the thread-rolling process, and the drill bit will center better. As it's not a blind hole, you can expect that the drill bit will catch on the screw and actually screw itself out. The heat from the drilling also helps soften the loctite. (A drill-press and a vice are highly recommended.)

Mine recently broke, but it was my own fault. I had it apart and forgot to loctite it when I put it back in. Once it loosened, it fatigued and broke. There have been some repairs on this already in the forums. One is to drill and tap for a 5mm bolt, another is to use a 4mm grade 12.9 bolt. I like the one that suggests you install a bolt from the backside of the clutchbell and use a loc-nut on the pinion side. If it ever breaks, you can easily unscrew the broken part as the head is still attached in the clutch-bell.

RE: baja clutchbell screw??
 

What clutch bell you using thats drilled right through so you can drill from the backside?

RE: baja clutchbell screw??
 

oh-oh....did I goof? I have an Integy steel CB sitting waiting to be put in and the hole goes right through. I thought the stock CB was the same. Guess I should remember...."never assume" anything. Sorry about that..........

RE: baja clutchbell screw??
 

on other forums they are tapping it out to m5 and using a bigger bolt....OR... use less torque when tightening the bolt and red lock tight

RE: baja clutchbell screw??
 

Get one of these puppies and kiss those issues gooobye!

http://img.photobucket.com/albums/v4...ierfitted1.jpg

Failing that stop riding the clutch.

RE: baja clutchbell screw??
 

Drilled and tapped mine for an M5 bolt... it loves it and it cost... nothing! I guess my engine just made too much power for the 4mm bolt along with the RR speed gears (very heavy) as I had been through EVERYTHING - and yes I even tried another bell carrier so I doubt putting that one on would have helped me.

RE: baja clutchbell screw??
 

Engine power won't hurt the stock bolt if the carrier is in good condition - breaking bolts have been happening since the release of the Baja with a stock CY23 and stock tin can exhaust. The engines torque load does not torque or strain the bolt under normal circumstances. And people have been running hot engines with alloy carriers and stock bolts with no issues as well so the bolt really does not get put under strain from the engine.

The problem happens when the bolt gets strained due to the stock carrier not doing its job properly - like when it gets deformed from heat, which is the problem the thread starter has, using a M5 bolt won't prevent the the stock carrier from deforming or bring his already damaged one back from the grave.

Heat also causes the carrier bearings to get cooked. Excess heat melts the bearings grease and causes it to run out like oil, the bearing then heats up even more since its running without lubrication. The extra heat may also push the bearings internal tolerances out of spec, thermal expansion causes the parts to enlarge which in a lubricant deficient bearing will wear the races and balls down - the slop/play from warn bearings will cause the bell and pinion not to run true causing excessive wear on clutch shoes, the spurgear and other things like the axle shaft of the clutch bell to break.

Unfortunatly the plastic material of the stock carrier acts like an insulator, heat from the clutchbell caused by the friction between the clutch shoes interfacing with the clutchbell travel into the bearings and from there has no where else to go, having it surrounded in heat conductive aluminium and cooling fins is an excellent cure for the cause of the problem - HEAT - and a better approach then just tyring to treat the symptoms.

Another good idea is shimming the pinion/clutchbell to remove excessive side to side slop, this will reduce lash effect which can fatigue the bolt and cause it to break. Steel weakens when under heat and the lash from when the clutch engages if the CB is able to move in and out will stress the bolt even more. You may get away with this if the bolt is relitivly cool but as heat rises the bolts strength decreases, reducing side to side play will not make the steel any stronger but it will put less stress on it. Fasteddy has a nice shim kit, maybe look into getting it, but don't over do the shimming and cause side loading on the bearings, this will wear them out quicker then if you just left them alone.

RE: baja clutchbell screw??
 

Well unfortunately I wasn't running the stock carrier, i was running the vertigo one :eek: with brand new bearings, shimmed up with minimal play and didn't even get time to heat up in most cases (I am talking literally 3-5 mins runtime in some instances). I tried a different carrier and it still happened, tried stock gearing, different bells, overhauled drivetrain with new bearings and checked for drag or binding - all to no avail. Basically the drivetrain (which includes that pesky little 4mm bolt) was designed to take the stock engine's 2 odd HP and low torque, now we run 4-5 HP engines with truckloads more torque without even blinking an eye. For me, with my setup the 5mm bolt fixed the issue, and it will for all those in a similar situaton to me.

RE: baja clutchbell screw??
 

well obviosuly the issue wasn't with the Vertigo carrier [sm=rolleyes.gif] if you tried another brand alloy one and it still happened. You were probably over torquing the bolt like alot of guys end up doing to keep it on since the star lock washers that go underneath are junk. Problem is if you torque it down too much you strain the bolt and when the gears warm up they expand a little which along with vibration can be enough to break it.

You're not understanding how your engines torque load is transmitted through the drive train, you could run an engine twice the power of the one your using and it won't strain that bolt any more then stock because the engines load isn't transmitted laterally on the bolt, its just a retaining screw to keep the pinion on the clutchbell shaft nothing more. The slot on the end of the CB's shaft and the corresponding groove on the pinion gear take the torque load, which at that point in the drive line really isn't all that compaired to the other end.

RE: baja clutchbell screw??
 

Who makes that part Lunar Wolf? Where can ya pick one up in the States?



Thanks
Chris

RE: baja clutchbell screw??
 

I'll PM you, don't want to de-rail this thread or turn it into an advert.

RE: baja clutchbell screw??
 

So why was I snapping pinion bolts then LW when they weren't overtightened? They were just snug with locktite to keep them from backing out - as you mentioned that star washer is pretty poor, and to boot i wasn't even getting a chance to warm up gears. You seem to have all the answers so i am interested to know.... And as I mentioned, your fave mfg's part wasn't to blame, all I did to fix the situation was increase the bolt's diameter as many others have done. We can't all be wrong, or can we...:eek:

RE: baja clutchbell screw??
 

Thanks Lunar, for keeping that on the PMs, appreciated.

Monaroman, I have a theory, but I don't know if it's right. The first time I heard of these bolts snapping, it immediately came to me. I understand what Lunar is saying though, so I'm now not so sure about my own theory, but I'll put it out there anyway...

Remember on your nitros, when you were assembling the clutch you do not need to torque the clutch nut, cos the rotation of the engine will torque it for you. I think the same thing happens with these. The stop/start and the sheer torque continues to tighten the bolt, until one day it snaps. Just an idea.

RE: baja clutchbell screw??
 

I know what you mean foxy, maybe lunar wolf will have the answer for us all

But until then a 5mm bolt is working and letting me do some bashing.

http://au.youtube.com/watch?v=e3YDa4IWTGU

RE: baja clutchbell screw??
 

NP foxy, i know theres a time and place and know to respect others threads.


Sorry mate, miss interpreted your use of 'rolleyes' to mean something else. Maybe lay off that smiley for a while eh?

Anyway there could be any number of reasons your engine not being one of them. If your clutch is slipping alot and or you have a habit of throttleing in the range where your clutch is barely starting to engage you'll heat the bell up alot, heat from that will also weaken the bolt. As foxy said the rotation of the pinion gear is anti-clockwise meaning the bolt will have a tendency to tighten itself, i don't think the point where it would shear off its own head but along with other factors can be enough to break it.

The fact that it is breaking is a clue to something else being wrong with your setup that you'll have to go through with a fine toothed combe, like a slightly twisted chassis or your gearplate might be warped, sometimes happens after an impact with the alloy one making the SG & pinion mesh at a slight angle - that will put uneven pressure on the pinion and might break the bolt - thats where those alloy rear engine mounts that are out there come in useful.

By replacing the bolt with a stronger 5mm one you've only masked the issue and it probably still needs to be addressed, when you've found the exact cause you can then decide whether its worth fixing or not. I'm not saying you or anyone else is wrong, but the approach is just attacking the symptom not going after the cause, the danger of which is you end up ignoring the signs that somethings wrong only to have the cause bite you later and it normally costs alot more to fix at that point. The most you would ever have to do is switch the stock bolt for a 12.9 grade alloy steel one (cheap as chips) but retapping the CB for 5mm is excessive.

edit: I'm sorry that you feel that i'm someone who seems to have all the answers. I'm not trying to post like i'm some sort of know it all but i do have some experience from maintaining alot of the local guys Baja's along with experience with other R/C's that have very similar setups, again as foxy said issues like this arn't exclusive to the Baja.

RE: baja clutchbell screw??
 

New CF gear plate and old alloy one, perfectly straight chassis, new gears and old ones, new bell (got heaps of these), new carrier and old carrier and stock carrier, new clutch shoes and old clutch shoes, engine tightened down and aligned, new bearings in bell holder and diff - tried it all mate, I'm not stupid - I may be an aussie but we can pick these things up eventually :D

Like I said there are plenty of people that have snapped the 4mm bolts, and I'm not talking the stock one - a good 12.9 bolt whether it be snugged up, done up tight, overtight, loose or whatever. There will always be excuses and people to second guess everything... I know a whole forum full of second guessers, all 5 of them.

But ultimately I was saying to the OP that if you want to bulletproof the setup, go 5mm. As you say if I have another problem and am just masking it with the 5mm bolt fix... its masking it well as i can now bash with confidence again - this IS NOT speculation from a bloke with a spanking clean baja who likes to talk about them a lot, this is advice from a bloke who bashes his baja and FG EVERY weekend without fail (and I don't mean putt around the backyard - I mean go hard or go home stuff).

RE: baja clutchbell screw??
 

increasing the bolts diameter would help , but id prefer to have two bolts on the pinion instead of one in the middle , they should make a pinion and bell so you can put two bolts in the pinion to the bell , so instead of one bolt in the middle it would be two bolts on both ends , this would stop the pinion bolts getting loose and hopefully stop pinion bolts snapping

RE: baja clutchbell screw??
 

You keep bringing this up so let me address this for you, do you have any idea how much you would weaken the 'key' on the bell by doing this? Well, you would render the key completely useless and actually reverse the affect you are looking for. Screws are not structurally strong in a rotational/shear situation, that is why there is a key, now you take and drill 2 holes in that key (keep in mind that the holes would be the 4mm and the key is 4mm), outbound enough to fit 2 screws, you might as well remove the key completely. That one key has far more strength than 2 screws could ever have, so without the key, you would be breaking screws all the time. Sorry to tell you, 2 screws is not the answer for more than just this reason. Let's take a look at all the pinions available for the Baja, they are all designed for single center screw, so, you want every manufacturer to change over to a 2 screw, weaker design, this would include HPI changing their whole design too?