shifting problem still exists - $2000 later

[Bharris]

I am sorry for the bad attitude, but I'm betting ready to sell a $15000 quad because I cannot get it to shift correctly.  I've been on every forum that I could think of and I cannot get any responses at all.

Way too difficult to shift into each gear - shifter hangs up just before engaging into the next gear, then it takes too much force click the shifter up into gear - and this goes for all of the gears.

Engine apart.  All shifter parts are well within specification according to the service manual (forks, fork shaft, shifting drum, all other components).  Is there anything else to look for?

I have spent way too much money - probably $2000 in this engine build alone (including having the top end ported) - what a shame after all of this that it still will not shift.  

Please - someone give some input.  It would be very appreciated.

[JesseA420]

start looking in obscure places. is there a burr behind a bearing seat preventing it from sitting perfectly straight?

when u are assembling the bottom end, put all the case bolts in but not torqued. does the tension on the action change when the cases are tightened down tight compared to just having the bolts in it untightened?

[dem3500]

Don't sell the quad. It's always fixable. Even if you have to buy another trans to put in it. You don't need to just give up on it.
Start simple.

Are you sure your clutch isn't hanging up? I know this sounds like I'm treating you like an idiot but you haven't given much detail so I'm going to start from the beginning. Does it free roll in gear with the clutch pulled in?

After this tank it out and do what Jessie said then move on from there.

Have you replaced ALL the lower end bearings? Most people only replace some because it's hard to get some of them out. I would start by replacing all of them.

You checked spec on all the components. We're they all on the low end of the spec? Sloppy tolerances can add up when you have a bunch of components working together

[Jerry Hall]

Is this your first time working on a transmission like this?

You are probably missing something simple.  Transmissions are not rocket science.  You may need someone else to look at it and retrace all of your steps.

The problem may not be caused by something out of spec. but possibly an assembly error in the shifting mechanism.  


Remove the shift shaft and the mechanism with the little springs, plungers and paws.  Leave the shift drum detent roller and spring installed that engages into shift drum star.  Now take a 12mm deep socket and rotate the shift drum while rotating the input and output shafts of the transmission and determine if excessive force is required to shift the transmission. The detent roller should finish rotating the shift drum into the next gear once you rotate the drum far enough that the detent roller is over the hump of each gear.  If excessive force is required, remove the detent roller and spring.  Shift it through the gears by rotating the shift drum with the socket. the shift drum shout rotate very easily with the detent roller and spring removed.  If excessive force is still required to rotate the shift drum, the problem is not in the shifting mechanism but between the cases.

Did you install the 2 dowels that align the two case halves?

[Tbone07]

Verify what year transmission you have. I usually count the teeth on the countershaft to determine. Then take the entire trans apart and reassemble like it says in the microfiche. Make sure you're not missing any necessary washers that might put something out of alignment.

[Langbolt]

Is your Shift shaft hanging up in your cases ? Pull off your Clutch cover.....tap the shift shaft from the shifter side so it disengages from the shift drum mechanism....about 1/2".....then try rotate the shift shaft with the shifter. If it's stiff or grabbing....there's your problem. Could be a bent shift shaft.....or a burr in the cases rubbing on the shaft. Give it a try and let us know. Try the easy things first.

[Bharris]

Thanks for the responses.  

The shifting problem started suddenly after about 2 years of flawless operation.  I can think of nothing that would have caused this - I was putting around trying to adjust a new carburetor, then realized that it wouldn't shift up without some serious force.  Based on this, I know that the problem wasn't due to something being installed improperly - so I know that that is out of the way.

Yes, this is my first time opening a 250R case (it's an '88 by the way).  I have built car engines, etc, but never opened a 250R case.  All of the testing instructions sound a bit confusing, but as I reassemble, I will keep these instructions in mind and hopefully be able to give it a test as Jerry indicated.

Clutch:  the clutch seems to be about halfway through it's life (it's a Henson Billet Proof).  There are very minimal notches in the basket from the plates - I have heard many people mention to file them a bit - I will do this before re-installing it.  Beyond that, it would roll forward with the clutch was engaged, but only after it warmed a bit - while cold, it would actually stall by engaging 1st gear which the clutch pulled in and at idle.  While warm however, it was fine.  I assumed that this was a typical 250R characteristic and it had never caused my any issue before - it is worth mentioning however.  

So I will go ahead and start reassembly soon.  Lets say I have about $500 more in the budget to spend on the engine - which transmission components should I go ahead and replace in hopes that I find the "bad" item?  Has anyone heard any feedback on the billet steel forks on eBay? I'm afraid to buy OEM, used ones, because they may be more worn than mine.

Thanks guys.

[fearlessfred]

The COC  will have you fixed up in no time at all .