KymcoForum.com
Scooters - 125 to 300 => People 250 => Topic started by: hypophthalmus on May 22, 2017, 10:13:19 PM
-
My rear fork is stuck to the rear axle shaft. I tried lightly hammering the shaft to loosen it, but I think I just bent the end of the threads. And messed up the threads of the axle nut while I was at it.
Does anybody know what size die I'd need to fix the threads on the axle? And if I can use a non-oem nut?
And possibly how to loosen the fork, which is still stuck.
-
I'll answer some of my own questions. It appears to be 16mm. Using a caliper, it looks like a 1.25mm pitch. But it's hard to be sure, since that's so close to 1.0 and 1.5.
I've tried letting spray lubricant sit, but I'm not sure it's doing much good. I have a map torch, but that would burn up the bearing dust seal.
-
Still not sure if just a regular m16 flange nut would work though.
-
I ordered this, http://www.ebay.com/itm/252512932201 (http://www.ebay.com/itm/252512932201) , honda part 90305-ME5-003 . It starts with the same five digits as the kymco part, and looks identical I think.
There's the possibility that the pitch and length are different I suppose. I'm hoping not.
-
Aaaand, to reply to myself for the last time today, there isn't a dust seal after all. Somehow I didn't realize I was looking at the bearing, which needs to be replaced anyways. So I'll try torching it.
-
My rear fork is stuck to the rear axle shaft. ...
Don't feel bad. I ran into the same problem with my 2005 Grandvista 250 around 8K miles or so and it was my first time removing the rear wheel on a scooter vs all the motorcycles I had owned that had a removable shaft. From the factory the spline is not packed with grease probably just machine oil. Overtime it rusts slightly. The secret is to lean the scoot on the left side - you could lean it against a wall and put a rug or blanket in between to prevent scratching. Then shoot WD-40 or any light penetrating spray. After letting it soak for a few minutes put the nut back on and tap it very lightly then attempt to work the wheel off. You could also reassemble and drive it for a day or two. Then the wheel should come right off. After getting it off and discovering I bent the threads slightly I lubed the spline with loctite brand antiseize and grease and also greased the nut and threads and was able to get the new tire /wheel back on. I came close to stripping the threads. After that I removed the wheel 4x - two flats, and two new tires each time with no problems.
TIP: Any time you use a die to re-cut the threads the size will be smaller and the next closest size will be SAE or English threads. If SAE then metric so you can use an SAE die instead and purchase a nut to match that thread pitch. If the threads just need reshaping then you could try the same metric size and thread pitch. Using the nut you could go to a machine shop or Grainger to get help determining the thread pitch and exact size of the nut.
-
I guess it's probably a good idea to put a light coat of lithium grease like you would with the front axle?
I'm not sure I understand what you're saying with recutting the threads, which makes me nervous. I think the only part that needs cutting/reshaping is the very end where it got bent by hitting it with the hammer. It doesn't look like anything else got damaged by trying to thread the nut back on, although the nut threads are messed up. So I was hoping that using the same size/pitch die would straighten out or cut the end and then just follow the rest of the threads.
-
Success getting it off.
Yesterday I used liquid wrench lubricating oil to no effect. This morning I took a torch to it, stopping when the part of the fork around the rubber bushing became too hot to touch (didn't want to risk damaging the bushing). Still stuck. Tried WD-40, still stuck.
I was reluctant to try the hammering with the nut on trick, but decided that it was my only option. It took a good deal of pounding with a 5lb sledge hammer, but I got it off. It didn't actually loosen and and come free, but rather was hammered off tiny bit by tiny bit. Thankfully the threads don't seem any worse for it.
It looks surprisingly not corroded. I wonder if the inner race of the bearing deformed a bit because the bearing was going. Although it's not at all obvious that the bearing is bad now (besides being burnt), there seemed to be a good deal of play when it was installed.
-
Success getting it off.
Yesterday I used liquid wrench lubricating oil to no effect. This morning I took a torch to it, stopping when the part of the fork around the rubber bushing became too hot to touch (didn't want to risk damaging the bushing). Still stuck. Tried WD-40, still stuck.
...It took a good deal of pounding with a 5lb sledge hammer, but I got it off. ...
Congratulations - what a great feeling to have that wheel off!
When I read 5lb hammer - I said OMG out loud lol. I have a 4 pound hammer so I know how hard that hits.
Great info thanks for sharing. If you have an angle grinder with a flat wire brush you might want to wipe an polish up the splines. I'm really surprised at the effort it took. The torch is another tool that can be very helpful if used with care. Btw, home depot sells a small black "Flame cloth" for $15 in plumbing dept that can withstand being hit with the torch flame it will actually turn red without burning.
When installing the new bearing you can put the new bearing in the freezer lightly head the wheel and grease the outside of the bearing and then drive it in with a block of wood.
Can you post some pictures - I would be great to see.
I found that the spline shaft & wheel is a very close fit. I would also use a small wire brush inside the wheel as an debris can jam the spline threads.
-
It is a great feeling, especially without having damaged anything further... I hope. Well, actually the wheel's still on since I still need to take the shock off, and the plastic. Since I need to wait for parts anyways, I guess it's a good time to do general maintenance anyways though.
Actually it was a four pound hammer. But yes, I was also surprised that it was so difficult. Even more so after seeing how the surfaces were so smooth.
Here's the rear fork with the bearing:
http://earthwoodjoinery.com/random/photo/scooter/rearwheelstuck/bearing.jpg (http://earthwoodjoinery.com/random/photo/scooter/rearwheelstuck/bearing.jpg)
I think the dark stuff on the inside of the bearing is burnt spray oil from torching it.
And here's the rear axle:
http://earthwoodjoinery.com/random/photo/scooter/rearwheelstuck/axle.jpg (http://earthwoodjoinery.com/random/photo/scooter/rearwheelstuck/axle.jpg)
Past the obvious corrosion on the shaft is where the bearing was sitting, on the clean looking spot. You can see on the end of the threads where I hit it.
And here's the axle nut with the damaged threads:
http://earthwoodjoinery.com/random/photo/scooter/rearwheelstuck/nut.jpg (http://earthwoodjoinery.com/random/photo/scooter/rearwheelstuck/nut.jpg)
It was cleaner than that when I tried to install it.
-
Cool pics. Threads look good.
-
WoW !
That reminded me of the olde days when my 2400 baud modem stepped down to 1200 baud because line quality was so bad.
Definitely could use some lubricant in there.
The threads on the axle do look coarse. I would use the silver kind of anti-seize on it to prevent it getting worse.
That nut can be re-purposed as a fishing weight, if you are a thrifty kinda person.
If you have somehow re-used it, purchase a replacement axle and nut in advance.
redk
-
What sort of lubricant should I use for the axle? Lithium grease? Should I use anything on the splines?
I'm definitely not planning on reusing the nut. Why are you suggesting replacing the axle though? I was planning on repairing the dinged threads and keep using it. It's pretty expensive I think (possibly around $60), and complicated to replace.
I might try using a dry teflon spray to protect the threads, since I have it on hand and it claims to be good for corrosion resistance.
-
I'm noticing now that with the wheel pushed in all the way, there's play in every direction. That's probably not normal, right? I'm wondering now if maybe the fork bearing didn't get messed up because the wheel was tightened at a slight angle.
-
I'm noticing now that with the wheel pushed in all the way, there's play in every direction. That's probably not normal, right? I'm wondering now if maybe the fork bearing didn't get messed up because the wheel was tightened at a slight angle.
It is ok to reuse the nut as long as you lube the threads. I reused mine with no problem. I would replace the bearing on the bracket (the part you call the rear fork). Wipe it off and write down the numbers - any place that sells bearings can get you one based on those numbers. Use antiseize on the spline shaft (silver looking oil & graphite paste) available at any auto store. You can also apply any silicone based grease which repels water on the spline. The wheel needs to be tight once the nut is on with no side to side play. Once you tighten everything up the play will go away.
-
I've reused the nut in the past. I'm just not about to reuse this particular one with the threads so messed up.
I'm sure the play in the wheel will be gone when it's tightened up. So I guess I don't have to worry about it.
Definitely replacing the bracket bearing (the Kymco manual calls it a fork, which is why I've taken to calling it). It had play in it in the first place, even before I torched it.
-
My bad - crazy the names they come up with. The OEM nut should cost more than ~$8? If the bracket was already messed up maybe a PO tried to remove the wheel. Also, I almost forgot - the proper way to remove the wheel is with a two or three jaw puller. The center of the axle has a small tapered hole to center the puller. That way no damage even if the spline is dry.
-
Not sure how much the OEM nut costs, but I ordered the honda nut because it looks the same and should get here much sooner. I ordered a different oem part ~3 weeks ago, still hasn't shipped yet.
What's a PO? I just pulled the wheel off, came off easily. I wouldn't have thought a special tool were necessary.
-
Not sure how much the OEM nut costs, but I ordered the honda nut because it looks the same and should get here much sooner. I ordered a different oem part ~3 weeks ago, still hasn't shipped yet.
What's a PO? I just pulled the wheel off, came off easily. I wouldn't have thought a special tool were necessary.
Sorry for the jargon - PO = Previous Owner.
OEM Kymco parts can take a LONG TIME which is why when the time comes I will probably buy a Piaggio BV350 for local dealer & parts support. Good idea on ordering the Honda part (hopefully it does the job).
Puller - Optional. Many times you will see the tapered hole in the center of a bolt in this or a similar situation. The idea usually is take it off witout a puller but if it is rusted on then the puller is used instead of a hammer to avoid damage. Also a ~1/2" fine thread bolt on a puller can apply ~ 2000 lbs of force AND even pressure so the wheel, etc is pulled straight and not at an angle. A common source for pullers is Harbor Freight or rent / loan from a local auto store. And you must choose a two jaw when that is required or a three jaw which ever is needed. I rarely use pullers so I gave all mine away. Then a few months later I need it but managed with a hammer.
-
i'm currently changing a tire on the back this helps thanx guys
-
Installing a new bearing seems problematic. It's deeply recessed, and too large for any sockets I have. I tried using the old bearing to hammer it in, alternating where I tap it on the outside edge. But I think I accidentally hit the seals. I tried putting it on the axle anyways, and the new one has lots of play.
-
Worst case, someone nearby says they can press it for $10.
I have the idea of using the old bearing again, but with a bottle jack instead of a hammer. But it might not be worth the risk.
-
I seem to remember someone recommending using a thread checker to check the pitch. I can't find it now though. But it was very good advice that I ignored, deciding instead to trust my caliper and my eyes.
The pitch is 1.5, NOT 1.25. Thankfully I caught it pretty soon. Some of the threads on the end are a bit damaged now. But after using the correct size die, the Honda nut (which is in fact the right size and looks basically identical) threads on perfectly. And I think the threads it actually tightens on are all good still.
-
Seems to me the nut is the easiest thing to replace, and the least expensive...
redk
-
With more than 90,000 miles on Kymco 250's and now GTi 300, I have been through this entire process a number of times, with mine and friends Kymco scooters. Removing the "swing arm" from the drive shaft, this is not an axle, can be done with a 3 point puller. Drill the swing arm, install the proper length bolts with fender washers and nuts on the back side, spray a penetrating lube on the bearing ( let it sit for several hours) and tighten the center puller bolt. Off it will come. The danger in pounding on the drive shaft with a 5# sledge is that this drive shaft, not axle, is attached to a gear and rides on a bearing in the transmission !!! These hidden parts can be badly damaged and are not fun to replace. use a high pressure grease, as we do on BMW splined shafts, on the splines and a good quality anti-seize at the bearing interface. Future rear tire changes will be a breeze !
-
With more than 90,000 miles on Kymco 250's and now GTi 300, I have been through this entire process a number of times, with mine and friends Kymco scooters....
Rocketmannn that is some impressive miles. I have two issues with my 2005 GV250 which I bought used in 2011 with 2600 mi. A couple of thousand miles ago the scooter was not fully disengauging the rear wheel. When I put it on the center stand there was a lot of drag when spinning it with the motor off. I dissembled the rear variator and greased it and replaced the large o-ring seals which solved the problem and the squeak that occurs when driving from a stop up a big hill. Now that problem has returned. Have you encountered this issue?
Also, last week out of no where I got off the highway and my scoot had 4 bars displayed on the temp gauge instead of the usual 2 bars. Only time I had that issue was when I changed the radiator fluid and got air in the system about 8K miles and 4 years ago. I removed the thermostat which seemed fine and added fluid. The system was not low and the coolant in the reservoir was still cool enough to put my finger in. Was this really and overheat or a glitch in the sensor? After I removed the thermostat I ran the scoot for 7 minutes at idle and again got 4 bars? But in the week since no problems.
Thanks
-
Rocketmann,
Those are good points about hammering the final shaft being a bad idea. To clarify, are you saying you need to drill into the rear bracket in order to use a three jaw puller on it though?
I used dry teflon spray on the splines and some red high temperature lithium grease where the bearing sits. Any thoughts on that?
mrbios,
Sorry if this all seems obvious:
Have you tried spinning the wheel without the brakes? Is the clutch sticking?
You can test the thermosensor with a multimeter. Although maybe if it's an intermittent problem, the sensor will only intermittently test badly?
Is the radiator getting hot?
How many bars is the maximum?
-
mrbios,
Sorry if this all seems obvious:
Have you tried spinning the wheel without the brakes? Is the clutch sticking?
You can test the thermosensor with a multimeter. Although maybe if it's an intermittent problem, the sensor will only intermittently test badly?
Is the radiator getting hot?
How many bars is the maximum?
I unbolted the rear caliper and spun the wheel it is definitely the rear clutch / variator. There are 5 bars on the temp sensor so 4/5. Normal operating temp is 2/5 and 3/5 if the temp is above 85 degrees on the highway. The radiator never got very hot, no steam, no overflow, etc.
-
Turning the wheel by hand, the movement should stop at the clutch bell, since the clutch is supposed to be disengaged. So the variator (and most of the clutch) shouldn't be involved.
Maybe bad circulation with a clogged radiator or failing water pump? It's a good sign that the system was full (checking from the radiator cap not the reservoir, right?).
-
Turning the wheel by hand, the movement should stop at the clutch bell, since the clutch is supposed to be disengaged. So the variator (and most of the clutch) shouldn't be involved.
Maybe bad circulation with a clogged radiator or failing water pump? It's a good sign that the system was full (checking from the radiator cap not the reservoir, right?).
Yes the reservoir was full. Water pump looked new and the thermostat was clean too. The clutch is not fully disengaged like it is stuck.
-
But is the radiator full up to the neck? If the system isn't properly pressurized, the reservoir can be full, but the system can still be low.
Somebody who understands these clutches can probably be more help. But I expect there's trouble with one of the springs. Once you get it resolved, you should also check the condition of the clutch pads and the bell.