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Help- can't get my gearbox back on

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Danforth DeSena
(@danforth-desena)
Posts: 18
Eminent Member
Topic starter
 

'82 R65LS.  Just replaced rear seal and lubed splines.  When I attempted to reinstall the gearbox, the right side does not push up flush against the bell.  There is about a 3mm gap.  I pulled it back out, inspected all the tabs along the edge thinking maybe one had some burrs.  They are clean and smooth.  Gearbox splines go into the clutch plate nicely, but push as I might, the right side will not mate up to the bell housing.  Do you suppose that, even though I used the clutch alignment tool, the clutch was tightened up with the clutch plate just a bit off to the right? 

Thanks for any help!

 
Posted : 12/27/2020 16:56
john stirling
(@arni)
Posts: 81
Trusted Member
 
Posted by: @danforth-desena

'82 R65LS.  Just replaced rear seal and lubed splines.  When I attempted to reinstall the gearbox, the right side does not push up flush against the bell.  There is about a 3mm gap.  I pulled it back out, inspected all the tabs along the edge thinking maybe one had some burrs.  They are clean and smooth.  Gearbox splines go into the clutch plate nicely, but push as I might, the right side will not mate up to the bell housing.  Do you suppose that, even though I used the clutch alignment tool, the clutch was tightened up with the clutch plate just a bit off to the right? 

Thanks for any help!

is the entire gearbox shifted to the right? if so your theory about the clutch plate is sound.

 

 
Posted : 12/28/2020 00:55
David Elkow
(@4949)
Posts: 284
Reputable Member
 

Just to throw in a thought - could an over abundance of spline grease prevent the splined shaft from inserting fully?  I AM NOT very familiar with this assembly, so a total shot in the dark. 

 
Posted : 12/28/2020 10:41
Richard W
(@wobbly)
Posts: 2520
Member
 

My money is on 1) mis-alignment of the friction plate, or 2) friction plate installed backwards.

NOTE: "Mis-alignment" is not a beauty contest winner.

Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.

 
Posted : 12/29/2020 07:13
David Elkow
(@4949)
Posts: 284
Reputable Member
 

Hmmmm, ... friction disc backwards ... interesting.

 
Posted : 12/29/2020 12:20
David Elkow
(@4949)
Posts: 284
Reputable Member
 

Well, you must tell us if you got your transmission back on, and what the problem was. 

 
Posted : 12/29/2020 19:08
Joe Hall reacted
Danforth DeSena
(@danforth-desena)
Posts: 18
Eminent Member
Topic starter
 

OK Guys, thanks for your thoughts.  I must be missing something really obvious.  Disc is in the right way- good idea though. I measured the distance from the OD of the spline hub to the ID of the pressure ring in four locations and it is off but only by about 0.5mm.  Figuring the rusty old ring might not be a reliable surface to measure off of, I tried inserting various drill bits into the space between the clutch plate and the front and back rings.  A 7/64" drill slides into one side and only 3/32" the other and these numbers and locations match the caliper measurements.  I can't imagine this amount (~0.4mm) would prevent me from sliding the gearbox back up tight against the bell.  Even if I remove the clutch and reinstall, I probably won't get closer than 0.4mm.  I have tried reinstalling the gearbox with the flywheel/clutch rotated to 6 different positions with no luck. The gearbox always refuses to mate on one side or the other.  Key point: On my last attempt I noticed it is possible to get in to mate on the right OR the left (but not both) without rotating the flywheel so this kinda rules out the whole "Miss Alignment" theory....

Oh yea, everything is clean, the input shaft goes into the plate splines slick as can be every time and there are no wires or cables in the way.  Should I just get beastly and start banging on it with a mallet????

 

 
Posted : 01/01/2021 08:47
Danforth DeSena
(@danforth-desena)
Posts: 18
Eminent Member
Topic starter
 

view of outside....

 
Posted : 01/01/2021 08:49
Stephen Hyde
(@sebascodegan)
Posts: 18
Active Member
 

I’m just blueskyin’ here, but could the issue be on the gearbox side?  Perhaps something shifted slightly?

 
Posted : 01/01/2021 10:50
James Strickland
(@8053)
Posts: 415
Reputable Member
 

Please DO NOT bang on it with a mallet. 

 

It's not entirely clear of your fit up trouble is an alignment issue, or a "close the gap" issue.

 

It appears that the stud on the upper right side of the "bell housing" has been inserted in the transmission mounting hole. If you can get the bolt started in the lower left hole, you might try the following.

Hand tighten those 2 fasteners, which are 180 degrees opposed to each other. Then use a wrench to effect 1/8 of a turn on each, one then the other,  to gently close the gap. DO NOT force anything.

Another thing you might try would be to assemble the clutch release/throw out assembly and then use the handlebar clutch lever to defeat the spring tension in the clutch assembly. If that worked, the clutch driven plate would be free floating inside the assembly. In that case, it would center itself.  

I have to wonder if the clutch push rod or release mechanism is creating an interference.

 

 

  

former Airmarshal, IL.

 
Posted : 01/01/2021 10:57
David Elkow
(@4949)
Posts: 284
Reputable Member
 

Need someone smarter than me here, but could something have gone wrong when re-mounting the flywheel?  Or, when installing the new rear main seal?

 
Posted : 01/01/2021 19:17
David Elkow
(@4949)
Posts: 284
Reputable Member
 

Seems like if the gap moves from right to left as you rotate the flywheel, then the flywheel may be wobbling. Like it isn’t seated correctly on the crankshaft?  I’m totally not familiar with this assembly, so again, need someone smarter here. 

(I have done this work ... just been far too long ago for me to recall the details.)

 
Posted : 01/01/2021 19:26
James Dahl
(@12506)
Posts: 1
New Member
 

I agree with the method that Jim Strickland has suggested.  The Friction plate needs to align so that the fitting flanges on the tranny and engine base match. Join the two with bolts just snug and aligned as close as possible then assemble the clutch lever gear and flex the pressure plate and then wiggle the tranny home.  Have done this several times my self to make it a snug fit.   The tranny and engine have snug mating surfaces with small flanges to proper fit.   Keep at it.  Jim in Alaska.

 
Posted : 01/01/2021 20:10
Danforth DeSena
(@danforth-desena)
Posts: 18
Eminent Member
Topic starter
 
Posted by: @12506

tranny and engine have snug mating surfaces

You're not kidding!  I should have seen this coming when I had to do the same "handlebar clutch lever maneuver" to get the gearbox off the bell at the beginning of this job.  Man, that IS a snug fit.  Anyway, your tip worked just as you guys said it would.  THANKS A TON GUYS!  ? 

 
Posted : 01/02/2021 14:12
David Elkow
(@4949)
Posts: 284
Reputable Member
 

Yeah!  I’m gonna remember this!  Glad it’s back together. 

 
Posted : 01/02/2021 19:53

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