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2005 RM 250.. Having Problems with 3rd Gear..?

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I’ve bought a used 2005 RM 250 very cheap because it has an issue with the trans. I’m having a very strange problem shifting into 3rd gear. Every gear shifts perfect other than 3rd. Example: While riding once you come out of 2nd gear and shift into 3rd it acts as a (false) neutral than will shift into 4th and 5th with no problems. Even when down shifting, it just seems 3rd gear doesn’t exists at all.

 

I drained the trans oil and the oil looked normal with no shavings or chunks. The magnetic drain bolt had very little shaving on it though. I replaced the oil with Amsoil 10w-40 MC oil. I haven’t taken the bike back out due to the rain.

 

Now while cleaning the bike I noticed the stock shift lever was bent then poorly bent back into shape and had 2 gouges on where maybe the bike was laid down and the shift lever hit the chain. The gouges match the width of the chain. The case saver was not installed when I got the bike. The shifter shaft appears to be straight and is not leaking at the shifter shaft oil seal.

 

I've done tons of homework searching here and other forums for this same issue and found some like it but not the same. Do you think maybe the bike was laid down while the rider was in 3rd gear and maybe jarred the gearshift cam stopper in that one spot..?

 

I Didn't buy this bike to flip, I bought it to fix up and go riding with my kid on his 2006 RM 125.. Thx 

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I have had a bottom end apart 2 twice in the 39 years I have been on this planet.  I can't help you.  I can, however, offer half assed advice.... :D

 

You need to tear down the engine and insect the gears closely.  You know where you are having the issue, so with it inspect where 3rd gear engages and look for worn out broken gears. 

 

Nothing from your outside observations leads me to think the shifting problem is related, but then again, see my first sentence. ;)

 

Good luck.  I think if you tear it down and inspect the gears, your find something amiss.  Then take a picture and post it up here for guys with tranny know how (not me) to help with. 

 

Rhino

Edited by RhinofromWA

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My guess is a shift fork, shift cam, or worn dogs in third gear. I'd tear it apart and get a list ready.

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Thx Rhino and Polishhammer.. I kinda figured I was going to have to split it. I just ordered a service manual and I should have all the specialty tools for the job. I'll report back once I get the engine broke down.

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I ran into a couple problems before splitting the case.. First I noticed the power valve mechanism shows excessive wear on the top and bottom were that gear slips in onto that shaft. I know I'll have to replace it but what causes this part to wear like this..?

 

My other problem is that the crank bolt is stripped.. The bolt was partially rounded off before I started turning on it. After it stripped, I tried using a little heat with the clutch hub holding tool and some vice grips to loosen the bolt with no luck. I don't want to chew the bolt head up so what do you recommend I do to get this bolt loosened up..?  (Maybe more heat..?)

 

 

Power Valve Mechanism.. It's badly wore/goudge Why..?

20140906_163853.jpg

20140906_163912.jpg

 

Stripped Crank Bolt.. Whats the best way to remove it..?

20140906_162253.jpg

 

Clutch Holder Tool I used to hold the gear..

$_12.JPG

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If it were mine I'd find a standard socket that's close to the nut size but a little too small and tap it on with a hammer. Have a friend hold the hub with the tool while you zap that nut off with an impact gun. If its too far gone cut a line throught the nut with a Drexel. Tap the cut with a chisel and the nut should split.

I know it all sounds rough but sometimes that's what it takes!

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20140913_133545.jpg

20140913_133716.jpg

 

I bought this Irwin attractor (turbo) socket set and the bolt came right out using a 1/2 electric impact gun and the clutch holder tool..

 

20140913_143013.jpg

20140913_144507.jpg

 

These shift forks definitely show some signs of wear.. But is it enough to cause a shifting problem only in 3rd gear..? I believe there's a service limit stated in the service manual but I check later.. 

 

20140913_142855.jpg

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The only other problem I see is with the gears. Look at the 1st pic.. then look at the 2nd gear from the left.. There a good size nick in the tooth.. The 3rd gear from the left has minor nicks too (not pictured)..Other than that all the rest of the gears look good with No missing or chipped teeth.

 

What should I do or what do you guys think I should look at next..? Thx

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Watch the detent arm- the small spring loaded part that moves the gears when you move the shifter. If this develops play and the amount of throw increases-it will cause missed shifts. You can weld up the gap so the tolerance is tighter. Other than that,the washers that space everything usually need replacing. I personally wouldn't worry about the small nicks in the gears. Is replace the shift forks. They are cheap and new ones will make it shift more predictable.

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Thx ac717.. I'll look into that tomorrow.. I'd like to focus on these shift forks and get some opinions..

 

20140916_172650.jpg

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The Gearshift Fork (Thickness) specs are 4.60 - 4.70 mm 

 

The Gearshift Fork (Width) specs are 4.80 - 4.90 mm

 

Those measurements printed in the 1st pic. is the (Width) which you'll see there under the service limit only on the one side of the forks. The Thickness of the forks are perfect on both sides..

 

Questions:

1. Is this a common issue with having worn shift forks..?

2. Should I replace all of these shift forks..?

3. Also looking at the middle fork, what causes it to wear like that..? 

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I am having a similar problem with a 1998 RM125.  Same fork damage.  My original problem was identical to yours.  No 3rd gear.  Like it was in neutral.  Upon tear down, found the long shaft for the forks broken.  Ours was a hollow tube.  Replacement was solid like yours.  After reassembly, now have a grinding and rear wheel lock up when I shift to 4th.  Desperate for info on this and my son is supposed to race in 2 weeks.  Upon tearing down again, noticed the wear on the shift fork like yours.  Maybe we are having the same issue.  I will post anything I find on here and will be watching this thread for assistance.

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The wear on the gear is from missed shifts. Basically bike half snag the gear and the force of the gear spinning against fork causes rub. Forks are cheap so I would replace the forks. Sounds like you guys have the rebuild manual. I Dont think they list the washer thickness that goes in the cases and takes slack out. If it does I would be checking that measurement. The more new parts you put in a the tighter the trans will be. Small marks on gear Dont bother me bit if you see nicks or pieces broke out then I certainly would not use them because it could break further.

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ac717.. Yes I have a factory service manual. I've done many top end rebuilds, crank seals and bearings and more but strongly believe in having the proper tools and a good service manual to be sure I don't miss anything..

 

TeamGotOil.. I hope this thread is a good help for you.. 2 weeks is right around the corner.. Good Luck...!!! 

 

Polishhammer..  " I'd tear it apart and get a list ready"  Man it's time consuming getting a parts list for a trans but it's worth it.. I'm learning a lot so far..  

 

Here's my parts list so far.. Plz tell me if you guys think I'm missing something.. These prices are from Rocky Mountain ATV and more than half are on backorder.. If you know of a cheaper place, plz let me know..? Thx

 

These are all OEM Suzuki Parts..

 

For all the Washers, Drive Bushings plus the Sprocket Spacer & 2 O-rings = $76.82 (basically every part to the trans besides the gears, circlips, all the shafts and bearings)

 

For all 3 Gearshift Forks------------------------------------------------------------------------- = $146.28 (Wow..!!!)

 

Primary Drive Gear Bolt (The bolt mentioned above that was striped)-------- = $7.20

 

Total............................................................................................................... = $230.30  (Free Shipping on orders over $100.00)

 

What do you Think..? 

 

 

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Just make sure the dogs on the gears aren't rounded or beat up. Also check where they engage Into the opposing gear. Sometimes it gets scratched up real bad there. If there is damage in these areas it will cause the bike to pop out of gear.

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Just make sure the dogs on the gears aren't rounded or beat up. Also check where they engage Into the opposing gear. Sometimes it gets scratched up real bad there. If there is damage in these areas it will cause the bike to pop out of gear.

Ok I'm not sure what the shaft on the top is called with all the gears assemble but I can say there's no signs of wear on the teeth, dogs or the opposing gears.. Although looking at the bottom set of gears that's disassembled show wear but I'm not sure whats passable or not. The bike shifted perfect other then skipping 3 gear.   

20140919_164821.jpg

 

Starting from the left you can see the wear on the dogs and the opposing gears.. The 3rd gear from the left shows greater wear.. Is that my 3rd gear..? Also the 2 gears on the right (not pictured) shows no signs of wear. I'm assuming that 1st. N. 2nd. 3rd. 4th. and 5th. starts from the left of that shaft.. Can some plz confirm this..? 

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Is that 1st. 2nd. and 3rd gear starting from the left..? Cause those look worn out especially the inner of that 3rd gear. The dogs that the shift fork goes into looks great other than minor rounding on one side of the dogs wear it contacts that 3rd. gear from the left. The 4th and 5th. gears from the left look like new.. I hope this makes sense

20140919_173814.jpg

 

Should I order the parts listed above along with those 3 gears that have wear or should I buy a good used trans and use the 3 gears from it along with the new parts..? 

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I really hope that one of you professionals out there or anybody that knows what I'm going threw could help me better understand. Your Opinion counts and I'm very interested to here what you have to say. I'd like to order parts now but don't want to until I get more info.. Plz help me.. Thx

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If it were my bike I'd buy the gears pictured that look rough (I think it's 3 of them), new shift forks, and any bearings that are rough or worn. Check the shift deterrent spring and the mechanism too that sits under the clutch basket. I'd put new main bearings, seals and check the crank.

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If it were my bike I'd buy the gears pictured that look rough (I think it's 3 of them), new shift forks, and any bearings that are rough or worn. Check the shift deterrent spring and the mechanism too that sits under the clutch basket. I'd put new main bearings, seals and check the crank.

That's what I was thinking, just change out what looks wore. Good thing I got a good deal on this bike..!!! All the bearings spin true and smooth but for cheap insurance I might as well at least change the crank bearings and seals while it's split open. I also have to rebuild the top end and figure out what causes the ware on that actuator arm on that power valve system.. Anybody..? It's pictured in the my 4th. post..  

 

My main focus is the (trans) internals for now.. I checked the deterrent spring and everything seems to be fine.. Once I get the case back together, I'll focus more on the out side.

 

I can't thank you guys enough for your help. Your input so far got me this far and hope to hear more replies., Thx again in advance..! 

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OK.. I finally gotten everything back together including the new top end and rebuilt the exhaust valve assembly.. Any bolt that was stripped or part(s) was replaced with a new oem one. I preformed a leak down test on the bench and No Leaks.. (Awesome)

 

I replaced everything in the trans mentioned above other then the gears, bushings and washers.. I was hoping it was just shift forks.. Every bolt that required loctite was located and every bolt was torqued to spec. I tripled (x10) check every part of the trans to make sure every part was in it's place before putting that case together.   

 

Bad News.. I started the bike and let it idle a bit then took it out and everything shifted PERFECT including 3rd gear.. But after a few slow passes 3rd gear locked up and gotten stuck in gear. I have to get off the bike and with force push the rear tire to get it to unlock the trans. After it did it the second time, I just parked the bike so I don't damage nothing. I'm telling ya, it freakin locked up the rear tire in 3rd gear and it won't come out of gear even using at the gear shifter.. Only if I push on the rear tire..

 

What do you guys think the problem is..? 

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I really wish someone could help me here.

I took the right side cover off and pulled the clutch and couldn't find anything wrong. So I'm going to pull the engine and spit the case again and replace those gears that appeared wore.

I just don't get it. The original problem is it'll shift 1st - 2nd then false natural 4th and 5th..

Now after installing all 3 new shift forks, 1st and 2nd are perfect and 3rd locks up the rear tire and can't free it up unless I push back on the rear tire. Once whatever unlocks, i can shift to natural. I can't even tell if 4th or 5th are working at all. Although it seems to go threw all the gears when the motor is on the bench.

Any tips would be Awesome. I cant wait to right it..!

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