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Need help with thrust load, thrust washers, and snap rings

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New to this forum so I apologize if I'm posting this in the wrong place. I recently bought an 07 CRF450R from a TSgt. here at the base my wife and I are stationed to, which helped take a little fear out of buying a used bike from just anyone. The bike was pristine and very well maintained with all service records and log book of oil changes, valve checks, and such. On my second time of riding the bike, a buddy asked to hop on it. Long story short, he brought it back with a huge hole in the crankcase. I could tell by how high he had the RPM's, that something bad was going to happen. Anyway, I tore the engine down and found that the rod split clean in half and destroyed everything. The only thing that was salvageable was the transmission and the head on up (had to replace intake valves, springs, seals). Since I'm new to 450's, 4 strokes, and working on engines, the only logical thing for me to do was to order $2,000 worth of parts and give it a go :)

Like I said, I've never rebuilt an engine before, but in the last 3 weeks I've spent 119.5 hours reading and studying them, and have also done 4 complete mock builds and tear downs using my old parts. The only thing that is throwing me off are the stinking thrust washers, snap rings, and spline washers in the transmission. My shop manual says to put the chamfered edges facing the thrust load side. Can someone tell me what the thrust load side is? Also I noticed on the original disassemble that even though a spline washer and snap ring may be next to each other, they are facing opposite directions. Can a thrust load side be from both directions? I saw where someone had posted that the thrust load side is always from the right side if you were sitting on the bike. If that's the case, why wouldn't the shop manual just say to have the thrust washers facing the right hand side? I tried finding the info online and have come up short, which makes me think it's something simple that I'm just not seeing. Any help would be greatly appreciated.

 

Also, if anyone has any tips or suggestions about doing this rebuild, I would definately welcome them. I've made over 200 pages of notes and diagrams, have cleaned, lubed and injected oil using a syringe (get into tight spaces) into applicable parts, then shrink wrapped, ziplocked, and labeled everything. I'm also going to try and do a 5th mock build before my final 66 parts arrive Tuesday. If you guys know of some problem areas or parts of the build that need particular attention, please let me know.

 

Sorry about the long post, but I do thank you for taking the time to read it.

 

V/R,

Keith Ryan 

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Edited by Keifer

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First of all- damn that sucks. So I take it you bought new cases?

The trans- sooo you took it apart? As in now it's out of order? I have pictures of how the trans is supposed to be but I think your better off looking at a parts catalog diagram like at partzilla.com or something. Advice- heat the cases up and freeze the bearings so everything just slides right it place. And a zip tie on the timing chain makes life easy when installing the cam gear.

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Yes sir, new cases, covers, crank, pretty much everything internal. I did take the transmission apart to clean everything and to make sure there was no metal shavings anywhere. As I took the mainshaft and countershaft apart, I put everything on a rod and kept it all in the same order and direction as it came off. Then I cleaned the shafts and installed the gears, washers, and snap rings in reverse order after cleaning and coating each one. So everything is just as it was when I got the bike. The only thing that has me worried is how the beveled edge of the snap rings and washers (like in the picture) have to face the thrust load, when I have no idea what a thrust load is and where it is coming from :) I've checked the parts catalogs and all diagrams I could find, but I can't find anything that gets as detailed to see the beveled edges on the washers, that I can see anyway. Maybe they are on there correct and I have nothing to worry about, or maybe the previous owner did some transmission work and put the washers facing the wrong direction, either way I can't say for sure. And with this kind of money involved, not to mention my pride, I have to be 100% on everything.

 

That's a great idea about the cases and bearings. That's the thing that worried me the most, installing the bearings. Figured it would be my luck to crack a new case trying to pound the bearings in. Which would have me stringing together unheard of cuss words as I'm slinging the rest of the parts across the garage haha.

I appreciate your help Diggla

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Man you turned that garage into a FBI lab lol. Put the rough edges towards the snap ring washers and keep it moving. Partzilla will show you the order of the parts if you get

To second guessing and here's a

Few more pics that might help. ImageUploadedByThumper Talk1397992021.114716.jpg

ImageUploadedByThumper Talk1397992046.264252.jpg

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Good deal! I appreciate it my man. Haha It's not just the garage that's like that, it's the entire house. My buddies think and say that I have OCD and am just a neat freak. What I'm not going to tell them is that since I turned 40, I can't remember crap anymore. If I don't have a certain place for everything, I end up putting things back where they don't belong and then forgetting where that was. "He's OCD" sounds better than "he's getting older and can't remember who he is,"  so I'll just go along with their OCD jokes :)

Edited by Keifer

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Lol I found the clutch basket holding tool very useful when I rebuilt mine. My vice is on the corner of my work bench so I locked it in to tighten down the flywheel and all the other gears so the motor wouldn't spin

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There's still a few tools I need to pick up before the rest of my parts arrive, the clutch holding tool is one of those. Didn't realize how many "specialty" tools are needs for bikes nowadays, I've ended up making a lot of my own in the last few weeks.

 

Had a moment of clarity today and finally figured out the whole washer and snap ring direction problem, which only confused me even more. Come to find out, these pictures in the shop manual actually mean something. Seems to me that they are exploded views, as if you are looking down on them, of the shaft, gears, snap rings, and washers, and they are there to show the direction the washers and snap rings face. I thought I had it all figured out. But of course, somebody had to throw this monkey a football.

 

At first I thought the diagonal lines were there to show the direction of the washers and snap rings. That would make perfect sense and would have the washers and snap rings all facing what I think the thrust load is. If the lines are going down and to the left, that means the beveled side would face left. If the lines are down to the right, beveled side faces right.

But then I zoomed in on the picture really tight. You can actually see a beveled edge in the diagram, which blows my line theory out of the water. Not to mention that the beveled edge in the diagram doesn't face what I think would be the thrust load on each gear.

 

My wife is an Air Force intelligence analyst. I printed these diagrams out and asked her to "analyze" them. They were wadded up and thrown back at me within 2 minutes, so I'm guessing they didn't make much sense to her either.

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For what it's worth either mine(06) didn't have beveled edges or I paid them no mind and just put them all together in order and it's ran fine since.

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Major undertaking you got there sir

Looks like you have done all the homework! Good luck to you! I hope she turns out great!

 

Way over my head though, i don't think i would attempt a bottom end haha

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The theory I have always followed is, if a gear mates up to a thrust washer the chamfered/beveled edge of thrust washer faces the gear surface. This is so sharp edge of thrust washer doesn't cut into gear. If a thrust washer mates up to a snap ring the chamfered side of thrust washer is oposite the snap ring. Snap ring chamfered side faces thrust washer. This insures the snap ring seats solid on shaft groove and can't slip off and sharp edge of snap ring doesn't cut into thrust washer.

Edited by susco64

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I'm with ya, Diggla. It probably doesn't make a difference and I'm positive I'm over thinking it, I guess the main thing I'm wondering is the "why" part of it. Why would it matter and what's the worst case scenario if they are installed wrong? I think I've come up with an answer and am in the middle of testing it using a thrust meter I built for testing drone motors and their lift capacity. (Can't believe I'm spending so much time worrying about a stinking washer!  :banghead: )

 

Thank you, Automag! I appreciate the luck and will let you know how it turns out. If it were up to me, I wouldn't have attempted to rebuild a bottom end either. I'm just too poor to pay someone to do it, and too stupid to cut my losses. :)

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Susco, I agree with your thinking. Both you and Diggla seem to be dead on from what I've been able to figure out. Excuse my drawing like a 2 year old, but here's what I've been able to figure out. You guys tell me if this sounds plausible or if I should toss this rebuild project out the window before I blow something up lol.

 

Did some testing on a thrust meter that I built using a small shaft and some gears. Set it up like the mainshaft in my '07 transmission and spun it using an electric motor running at about 440KV. As it was spinning I moved, what would be the M3 gear in the picture, back and forth between M4 and M5.  There was a definite split second increase in the load as M3 impacted M4 and M5. Apparently, these washers and snap rings are stamped with the beveled edge to kind of combat that impact, or what they call a thrust load. So in the picture, the spline washer bevel between M4 and M3 would face M4 to absorb that impact and the snap ring would face M3. The snap ring and washer between M3 and M5 would just be a mirror image. 

 

If this is right, why couldn't the shop manual just say that? hahaha

 

Again, Susco and Diggla, thank you very much guys, I really appreciate the help! 

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well there stamped because 99.5% of washers are stamped out of plate. the same with snap rings.

i always put the sharp edge of the washer towards the gear because its the actually flat side. and then i put the sharp side of the snap ring facing away from the gear, if you put the beveled edge away form the gear it will be easier for the thrust to push the snap ring out.

 

but i don't think the direction of the washer is all that critical.

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That's the direction of the snap rings and washers that I came up with too, englertracing. I was going to say that I hate that it took me 3 days to realize why they should be that way, but I'm actually glad for all the info I found and that you guys gave me. I know 10x more about transmissions than when I started and am not just  slappin' a part in because a book says so. Not to mention that if I have a problem after this build, I won't have to wonder if the washers or snap rings could be the cause. I appreciate it buddy.

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I just went through something similar and I'm sorry you need to as well.  Mine was intended to be preventative until all hell broke loose.  

 

It's not all that hard of a job and I had the same amount of experience you now have lol.  All I can do is agree with digla, freeze the bearings and heat the cases.  I did have a bearing drive on hand which did come in handy.

 

http://www.thumpertalk.com/topic/1074780-2009-bottom-end-rebuild/

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I'm gonna solve this for good.. The drawing- you can tell which way it's going by the height and width of the gears in the diagram.. Therefor you can see which beveled edged of in what order. Boom! Sorry but after looking at it again it's quiet clear. When I did mine I must have just went by the pictures and didn't put that much thought into it(I do that a lot, who needs directions anyways?!

Jk) but really just go by the diagram and stop stressing it

Edited by Diggla117

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well there stamped because 99.5% of washers are stamped out of plate. the same with snap rings.

i always put the sharp edge of the washer towards the gear because its the actually flat side. and then i put the sharp side of the snap ring facing away from the gear, if you put the beveled edge away form the gear it will be easier for the thrust to push the snap ring out.

 

but i don't think the direction of the washer is all that critical.

You don't want the sharp side of thrust washer mating the gear. Another issue you guys are overlooking is the lubrication abilities. A flat washer will stick easier to another flat surface, creating more wear and drag on gear.

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1500C.png

 

The flat side goes away from the side that will receive the impact from the gear if the snap ring is being used for a stopper. If the gear slides toward another gear. IE #29 that retains #14(5th gear). Third engages it when its driving, but it needs to stay put.  What its doing is keeping the gear running on the bushing. The flat side would be pointed at #9, so when it pushes on the snap ring, its not trying to spread the snap ring on the shaft by allowing that tiny radius to wedge it open under thrust. Its that with all transmissions. Honda or otherwise. You just have to look at the trans and understand where the load would come from.

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I believe I'm more confused than Keifer now :( Understand your confusion manual is very confusing.

Here's how I would assemble.

Mainshaft left to right as in service manual diagram Keifer posted.

TW1 flat side left, TW2 flat side left, SW1 flat side right, SR1 flat side right, SR2 flat side left, SW2 flat side left

Countershaft

TW1 f side left, TW2 f side right, TW3 f side left, SW1 f side right, SR1 f side right, TW4 f side left, TW5 f side right

Edited by susco64

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After finally looking at the manual is swear it's not that complicated. Forget about the thrust load and all that it SAYS. It clearly shows it in the diagram ImageUploadedByThumper Talk1398121072.678511.jpgImageUploadedByThumper Talk1398121095.277886.jpg.

If you took them all off with a long screw driver, hard wire whatever then it should all still be in order anyways.

Hope you got it Now OP

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