Let's talk thread lock (and shimming)
#1
Let's talk thread lock (and shimming)
I've never used thread lock on my clutch bell to drive shaft setups and have had zero problems....until now.
The short version is I noticed the other day my clutch bell on my Mugen (Werks B6) has more play than I had initally set. Upon inspection, the screw going in to the shaft pin was a ittle loose (enough to move the bell out about 1mm). Initially I thought perhaps it was the shimming, but I've gone through about a gallon with this setup and it just now came loose. I tightened it up (bell spins freely) and after about 1 tank I noticed the additional play is back.
I'm VERY worried about putting thread lock on this. If I have to as a last resort - Iwill. It uses a 3x8 button head, but will switch to cap head in the event I strip it a little easier to get out.
Theortically you'd think there was some binding causing the screw to come loose, but as noted the shim set up is good (as I know them to be).
Has anyone else has this issue? How manyof you thread lock this screw?
Thanks!
EDIT: I just checked it and the screw was TIGHT,but there wasatleast 1mm more play then whenI set it last - earlier this week when I first noticed it. Either that or I'm going mad (always a possibility). Bearings are fine, spins like on ice, etc.I'll clamp itdown again (this time with a locking washer) and see what happens thisweekend.
#2
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RE: Let's talk thread lock (and shimming)
I use blue Loctite when I want thread locker on small parts (i.e. models), however on parts I'm nervous about (concerning eventual disassembly), I use the HPI crap. It works, but doesn't make removal difficult. And I do use it on crankshaft-clutch retaining screws if that's what you're talking about.
http://www3.towerhobbies.com/cgi-bin...?&I=LXDHK5&P=7
http://www3.towerhobbies.com/cgi-bin...?&I=LXDHK5&P=7
#3
RE: Let's talk thread lock (and shimming)
If the clutchbell is shimmed properly and the bearings are good, and the clutchbell retaining screw is tight as has been stated, then the clutchbell shouldn't magically get "loose" enough to have 1mm play. Either it's not shimmed properly, or the bearings are getting loose.
I use blue loctite on my clutchbell retaining screw without issue.
I use blue loctite on my clutchbell retaining screw without issue.
#4
RE: Let's talk thread lock (and shimming)
Thanks. Bearings appear to be in good shape (not new, but not blown). If it happens again I'll replace them and try the weak HPI "crap". I'd like something a little weaker than blue. I'm pretty confident it is shimmed correctly...I'd think if there was a bind this would have happened already but who knows. I'll find out soon enough. ;-)
#5
RE: Let's talk thread lock (and shimming)
There are two ways to have an improperly shimmed clutchbell. Too loose or too tight with the former being more likely with all other variables being right.
When you say the bearings are "good", are you taking them out of the CB and checking for lateral play? If the ball bearings or the races that hold them are worn, the bearing will spin "like its on ice" but will be loose with side play.
I'm not picking on you - but if it is tight at the start and comes back loose, something isn't right.
When you say the bearings are "good", are you taking them out of the CB and checking for lateral play? If the ball bearings or the races that hold them are worn, the bearing will spin "like its on ice" but will be loose with side play.
I'm not picking on you - but if it is tight at the start and comes back loose, something isn't right.
#6
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RE: Let's talk thread lock (and shimming)
I never use any form of thread lock on any RC crank thread...never had a problem.
As you say the screw in the end was tight, then it would point to something other than the screw coming loose.
As you say the screw in the end was tight, then it would point to something other than the screw coming loose.
#7
RE: Let's talk thread lock (and shimming)
ORIGINAL: 1QwkSport2.5r
There are two ways to have an improperly shimmed clutchbell. Too loose or too tight with the former being more likely with all other variables being right.
When you say the bearings are "good", are you taking them out of the CB and checking for lateral play? If the ball bearings or the races that hold them are worn, the bearing will spin "like its on ice" but will be loose with side play.
I'm not picking on you - but if it is tight at the start and comes back loose, something isn't right.
There are two ways to have an improperly shimmed clutchbell. Too loose or too tight with the former being more likely with all other variables being right.
When you say the bearings are "good", are you taking them out of the CB and checking for lateral play? If the ball bearings or the races that hold them are worn, the bearing will spin "like its on ice" but will be loose with side play.
I'm not picking on you - but if it is tight at the start and comes back loose, something isn't right.
#8
RE: Let's talk thread lock (and shimming)
As a follow up, I checked for bearing lateral play on the shaft and there was none, but with the bell installed it there was play. The bell is in like new condition
Below are some pics. the first of my clutch setup (it has a gallon on it, but its held upwell). The shoes are just now starting to show a little wear.
The second pic shows my current hardware to the left (with bearings I willreplace withto the right) withsome of myclutch shims to the right. The bearings have 1/2 gallon onthem.
In all candor, tt is rare I will use the stock shim setup as I run a lot of aftermarkets, and even the stock shim "instructions" can be too tight/loose. You can also seeon the left I used a cap screw instead ofbutton head.I use capheads on a few other vehicles and no problems.
With that,along with replacing the bearings I'll reshim it with some different hardware..,it can't hurt.;-)
Thanks
#9
RE: Let's talk thread lock (and shimming)
I usually have to have shims inside and outside the clutchbell. If there is a washer behind the capscrew in the crank, make sure there is virtually no movement between the outer clutch bearing and that washer/capscrew. Also to note, tolerances expand when those parts get hot. 1mm is a LOT of play and is excessive. Thermal expansion will NOT create that much slop though, unless your clutch parts were made of brass or some other metal with a high thermal expansion property.
#10
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RE: Let's talk thread lock (and shimming)
I always use a dab of blue threadlock. Worst case scenario I cut a slot in the screw with a dremel and a little heat from a micro torch and it come right out with a standard screwdriver...never been a problem for me at all....even at the track.
#11
RE: Let's talk thread lock (and shimming)
ORIGINAL: 1QwkSport2.5r
I usually have to have shims inside and outside the clutchbell..
I usually have to have shims inside and outside the clutchbell..
ORIGINAL: 1QwkSport2.5r
If there is a washer behind the capscrew in the crank, make sure there is virtually no movement between the outer clutch bearing and that washer/capscrew.
If there is a washer behind the capscrew in the crank, make sure there is virtually no movement between the outer clutch bearing and that washer/capscrew.
ORIGINAL: 1QwkSport2.5r
Also to note.....mm is a LOT of play and is excessive.
Also to note.....mm is a LOT of play and is excessive.
ORIGINAL: rccheech
I always use a dab of blue threadlock. Worst case scenario I cut a slot in the screw with a dremel and a little heat from a micro torch and it come right out with a standard screwdriver...never been a problem for me at all....even at the track.
I always use a dab of blue threadlock. Worst case scenario I cut a slot in the screw with a dremel and a little heat from a micro torch and it come right out with a standard screwdriver...never been a problem for me at all....even at the track.
#12
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RE: Let's talk thread lock (and shimming)
Its not as hard to get out as you think if it does strip...one day it will...lol I promise. If you ever have trouble I could walk ya through it.
#13
RE: Let's talk thread lock (and shimming)
Ideally, the clutchbell should be seated so the bell covers the clutch shoes completely and has virtually NO play in/out. It only should have enough play to allow the bell to spin freely. Remember, any amount of play here will increase as the parts heat up.
+1 on what rccheech is talking about. I've had to replace that capscrew before, using a dremel and small cut-off wheel does the trick every time.
+1 on what rccheech is talking about. I've had to replace that capscrew before, using a dremel and small cut-off wheel does the trick every time.
#14
RE: Let's talk thread lock (and shimming)
ORIGINAL: 1QwkSport2.5r
Ideally, the clutchbell should be seated so the bell covers the clutch shoes completely and has virtually NO play in/out.
Ideally, the clutchbell should be seated so the bell covers the clutch shoes completely and has virtually NO play in/out.
ORIGINAL: 1QwkSport2.5r
+1 on what rccheech is talking about. I've had to replace that capscrew before, using a dremel and small cut-off wheel does the trick every time.
+1 on what rccheech is talking about. I've had to replace that capscrew before, using a dremel and small cut-off wheel does the trick every time.
#15
RE: Let's talk thread lock (and shimming)
I don't know why you would want any in/out play on the clutchbell. It seems to me that would beat the bearings up more besides possible uneven wear of the shoes. I set my clutches so there is only enough play to not bind. I keep my clutchbell as close to the flywheel as I can without it touching the flywheel or rubbing on the outside surface of the clutch shoes.
I get several gallons of fuel to a set of aluminum clutch shoes on a .28 engine in a 13lb monster truck running in dirt, grass, and anything else I can find. I replace clutch bearings when they go bad, usually once a year. And these clutch bearings I've been using are $1/each from AvidRC. This regimen wasn't taught to me, it's just what I've found to work the best for my applications. I do the same thing on my 65mph Jato as I do on my slow 45mph 1/8 monster trucks. So take it for what it is, merely my opinion.
I use blue thread lock on any metal screw going into any metal part on the car/truck. Never had one fall out yet, and I've never needed a torch to get a screw out either. Again, that's just my experience.
I get several gallons of fuel to a set of aluminum clutch shoes on a .28 engine in a 13lb monster truck running in dirt, grass, and anything else I can find. I replace clutch bearings when they go bad, usually once a year. And these clutch bearings I've been using are $1/each from AvidRC. This regimen wasn't taught to me, it's just what I've found to work the best for my applications. I do the same thing on my 65mph Jato as I do on my slow 45mph 1/8 monster trucks. So take it for what it is, merely my opinion.
I use blue thread lock on any metal screw going into any metal part on the car/truck. Never had one fall out yet, and I've never needed a torch to get a screw out either. Again, that's just my experience.
#16
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RE: Let's talk thread lock (and shimming)
[quote]ORIGINAL: JohnP2
ORIGINAL: 1QwkSport2.5r
Ideally, the clutchbell should be seated so the bell covers the clutch shoes completely and has virtually NO play in/out.
Ideally, the clutchbell should be seated so the bell covers the clutch shoes completely and has virtually NO play in/out.
#17
RE: Let's talk thread lock (and shimming)
You're right. Metal does not contract when heated. It expands. For this reason you always adjust the valves on a 4-stroke (with solid lifters) with the engine cold as the tolerances tighten when the parts are hot. Differing temperatures will give differing tolerances.
Now, I doubt a hardened clutchbell will expand much, but I surely wouldn't leave any more play than what is necessary. There's always more than one way to skin a cat though.
Now, I doubt a hardened clutchbell will expand much, but I surely wouldn't leave any more play than what is necessary. There's always more than one way to skin a cat though.
#18
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RE: Let's talk thread lock (and shimming)
I am another to shim the clutchbell just enough to feel a snick of play....no more.....on big to small engines and on/off road.
There is definately no need for 1mm in my mind....but do what works for you.
There is definately no need for 1mm in my mind....but do what works for you.
#19
RE: Let's talk thread lock (and shimming)
ORIGINAL: 1QwkSport2.5r
I don't know why you would want any in/out play on the clutchbell. It seems to me that would beat the bearings up more besides possible uneven wear of the shoes. I set my clutches so there is only enough play to not bind.
I don't know why you would want any in/out play on the clutchbell. It seems to me that would beat the bearings up more besides possible uneven wear of the shoes. I set my clutches so there is only enough play to not bind.
Not picking on you now , but I do know a lot of manufacturers (M2C, Buku, Losi, Werks,etc.) advocate some play...which again is different than no play..Regardinguneven shoewear....I've never noticed it. However, will admit I've yetto go a year without having to changeclutch bearings (especially the $1.00).
Anyway, good stuff. I did learn some things so appreciate the information.
#20
RE: Let's talk thread lock (and shimming)
You're over-thinking this. I've said already; shim it so that the shoes are completely covered, the clutchbell doesn't touch/rub the flywheel or clutch shoes, doesn't move in and out, and most importantly doesn't bind. If you have the right thickness shims, you should have no issue shimming the bell to have zero play and not bind. No play does NOT mean it will bind. There is too little, too much, and just right.
#21
RE: Let's talk thread lock (and shimming)
ORIGINAL: 1QwkSport2.5r
You're over-thinking this. I've said already; shim it so that the shoes are completely covered, the clutchbell doesn't touch/rub the flywheel or clutch shoes, doesn't move in and out, and most importantly doesn't bind. If you have the right thickness shims, you should have no issue shimming the bell to have zero play and not bind. No play does NOT mean it will bind. There is too little, too much, and just right.
You're over-thinking this. I've said already; shim it so that the shoes are completely covered, the clutchbell doesn't touch/rub the flywheel or clutch shoes, doesn't move in and out, and most importantly doesn't bind. If you have the right thickness shims, you should have no issue shimming the bell to have zero play and not bind. No play does NOT mean it will bind. There is too little, too much, and just right.
Thefacts are:I advocated .25-.5mm of play. You advocated NOplay. Idisagree withyou. This is not my firstrodeo with shimming andwill continue with the advice of M2C, Werks, Buku, Losi, Hot Bodies, etc. who ALLrecommend.25-.5mm play.Oh, and I have worked with ALLthose clutches, so yeah....I'm not afraid toconsult with TRUE experts and while I gain my own experience. Oh, and I called the guy who taught me a lot about clutch setups (I won't drag his name into this....BUT he is the owner of one of the brands I just noted)....and he re-verified that "some" play required, and that "no" play will bind AND jack up your bearings. He was like "why are you even asking this?" and told him....nevermind. ;-)
So pleasedon't come in here like some "shimming Jedi" and have an "I am right and anyonewhodisagrees with me is wrong" attitude....especially when your stance of NOPLAY is on very shaky ground as it is.Instead of touting how you go one yearwithout changing $1 bearingsandhow you have a 65mph Traxxas Jato, try to open your ****ing mind . Then maybe YOU will learn something. No matter how far I go in this hobby, I will always keep an open-mind and never think I am to good to learn anything- but instead continue to find ways to improve.. Try it. You'll get much wiser that way, I assure you.
It'srare for meto lash out like this...but DAMN!
I'm done with this thread (so everyone put theirpopcorn away)and have no hard feelings toward you.. Once again, just watch who you talk down to.
#22
RE: Let's talk thread lock (and shimming)
Sorry if you felt I was talking down to you. I didn't intend to. I was just posting of my meaningless experience. My clutchbells do not move in an out at all. They seem to work just fine that way. Do you need to do it my way? Of course not. I wouldn't do it if it didn't work. Maybe I'm just lucky that I get as much out of my clutch shoes and bells as I do. It makes no sense to want your clutchbell to be able to move in and out even .5mm, but that's just my opinion. If what you do works for you, great. At the end of the day, that's all that matters, right?
I have an open mind. I never claimed to be an expert, just stating my opinion like 95% of the members of this forum do. I am always open to learning something new... But if I have already tried something and had poor results from it I don't keep doing it. 3 sets of bearings and 1 set of aluminum clutch shoes in 1 gallon of fuel is poor results if you ask me. I got better results by changing the setup.
I have an open mind. I never claimed to be an expert, just stating my opinion like 95% of the members of this forum do. I am always open to learning something new... But if I have already tried something and had poor results from it I don't keep doing it. 3 sets of bearings and 1 set of aluminum clutch shoes in 1 gallon of fuel is poor results if you ask me. I got better results by changing the setup.