Rethreading rear axle, replacing nut

[hypophthalmus]

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.

[mrbios]

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.

[hypophthalmus]

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.

[mrbios]

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. 

[Ernestt]

i'm currently changing a tire on the back this helps thanx guys

[hypophthalmus]

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.

[hypophthalmus]

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.

[hypophthalmus]

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.

[Redk]

Seems to me the nut is the easiest thing to replace, and the least expensive...
redk

[rocketmannn]

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 ! 

[mrbios]

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

[hypophthalmus]

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]

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.

[hypophthalmus]

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?).

[mrbios]

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.