Gearbox issue 400 LC

[WayneL]

Hi All

I have a gearbox that sometimes plays up....

When down changing from 3rd to 2nd, I sometimes end up in neutral ( press down on the lever and you end up with a terrible crunching sound in first gear or lift up the lever to get to 2nd)

I run motul transoil. I tried a vmx80 grade oil as run by some other folk on a different forum and all that does is drag the clutch.

I haven't pulled the engine down yet, but any ideas on what I would be looking for? (I've never split an engine before)

thanks

 

[oldbikedude]

First check the shift linkage & pawls on the shift drum inside the case behind the shifter. All should be free & smooth moving. Not sure how to tell what it could be without splitting the cases. I just had to do my trans but due to different issues. I have a thread with some pics. should be the same gearbox.

 

[dukkman]

Do not remove the kickstart or gearshift levers from the clutch cover.
If you do you'll wonder why you did.

 

[WayneL]

Thanks

Nice thread oldbikedude and good photos.

Dukkman - I learnt that one back in the 80's

 

[2premo]

Hi All

I have a gearbox that sometimes plays up....

When down changing from 3rd to 2nd, I sometimes end up in neutral ( press down on the lever and you end up with a terrible crunching sound in first gear or lift up the lever to get to 2nd)

I run motul transoil. I tried a vmx80 grade oil as run by some other folk on a different forum and all that does is drag the clutch.

I haven't pulled the engine down yet, but any ideas on what I would be looking for? (I've never split an engine before)

thanks

help me follow your thinking, 3rd to 2nd finds a false gear? in (crunch) is that when you get the false gear, so does it crunch and give a false neutral on the same shift, do you get a crunch on upshift from first to second
maybe if I try to follow this differently you end up with a false neutral and if you try to downshift it crunches into 1st or if you upshift you actually get to the target 2nd gear, if that is correct you shifting drum has an issue, there is a roller with a spring that holds the gear, look at 2nd gear where the roller sits and see if something looks odd, typically the early Husky shift forks were pretty hard to bend but not impossible so if the detent is not the issue most likely you will need to go deep

 

[oldbikedude]

I had to replace the pins in the end of my shift drum because some of them wore a flat spot in them. It wasn't my main problem but they do wear out. I would imagine that could cause the lever that push/pulls the shift drum back & forth to wear prematurely as well. I think I read somewhere that the 10mm bolt on the end of the shift drum can back out a little causing binding problems. Just somethings to check before full teardown.

 

[fran...k.]

Drain the oil and examine. I can make some comments as to what to look for should the oil be full of chips and you dis-assemble.

I believe no 400 lc had cr transmissions so this is for the wr xc six speed.

Second is on the end of the shafts near the clutch half round thing and the sprocket. The bearing next to the sprocket is generally the first to go and might damage the bearing pocket. Dirt can get past the seal at the clutch half round and get into that one, never seen the pocket damaged there. The pocket for the bearing near the clutch is generally not a tight fit anymore. It isn't really a pocket more a free standing loop with a ring around the bearing for axial location. That bearing is close to first gear, I havn't seen a bad one there yet or put a sleeve in the bearing pocket like it probably should get. Put the shift rods on a flat surface and see if they are straight perhaps crashing bends one it isn't uncommon to find the one with two shift forks on it not straight. If you do take it apart it is pretty easy to assemble the cases without the crankshaft to test out various things until you are pretty sure you have it figured out.

 

[suprize]

Hi Wayne, I had a similar drama after Harrow but it turned out to be the shift lever rubbing on the external case!

its easy to rip the clutch cover and clutch out to inspect the shifter mechanism for springs and worn shift linkage. if that's ok, then you will need to look at the forks and drum

im using ATF in the 400 and it seems ok so far. its the ford oil for early Borg Warners ATF - F. its still a monoshock as the stuck one has gone MIA at Mr Mc Hanics. I will have to sort something for nxt year. Cheers, have a good xmas and New Year.

im planning on some rides up north in 2014 so may catch up

 

[WayneL]

Thanks too all.

2premo

down changing 3rd to 2nd - it seems to go past 2nd and into neutral (between first and second I believe, ie. when I press the lever down I end up in 1st, the crunch sound I imagine is associated with the engine rpm, if I lift the lever up I end up in 2nd and it just pops right into gear)

Fran...K

No unusual metal pieces in the oil (yet). the bike is a WR400.
I'll pull the side cover off and have a poke around.

All
I will review the manuals and the check the bike, hopefully its something simple.

Another remedy would be ride faster up hills, use the clutch and pick better lines

Surprize - I'll miss Harrow next year as I'm riding the A4DE (4 day) which is in mid August, not sure if I'll ride the WR400 or splurge on a modern bike.....I'll ride in 'masters' so it doesn't matter what I ride...... except for creature comforts

 

[suprize]

after riding a husaberg 500 on the week end id go with the husky... the hberg near beat me to death....nice brakes though. where is the a4de?

 

[fran...k.]

Since you are not sheeding metal particles perhaps I can mention some things.
The spring that returns the shifter can be deformed in the process of putting the cover on. I think it took ten years before I bent one.
As mentioned prior the six little pegs that the claw grabs onto can wear, the claw itself as well. I couldn't figure out how to take that thing apart and just swapped in a whole better drum assembly on the last one I had apart. Perhaps you are grabbing more than a one sixth turn somehow. Going fron third to first would be beyond the ability to engage the dogs smoothly while moving would be a pretty safe assumption.
The spring and ball that make the drum stop at an exact location is not accessible through the side cover at least without some bizzare equipment. In some of these bikes, even a bit earlier model it seems that say if you want to go from second to third fast once in second just a little down touch that is less than gear change force makes the shift when ready quite more reliable.