Swing Arm Maintenance

Hello - New to the forum. Have a question on swing arm adjustment after bearing replacement.
Bike's a 1980 XJ650 Maxim. No indication they need changing except they are 36 years old. Probably as dry as the wheel bearings were when I replaced them.
The Hanes manual describes torqueing the right hand stub bolt to achieve the correct bearing tension. Question is what do you do with the left hand one? Just bottom it out, or eyeball center on the swing arm, lock the left one down, and torque the right hand one? Any help appreciated.

 

Bottom the left one, adjust with the right one.

 

..and then tighten the locknut on the right adjuster. Also be sure to bend the locking tabs over one face of each nut (be sure to check that the tab is in good-enough condition to be reused, or just get new ones).

 

Hello gracious forum experts. New thread topic on my 1980 XJ650 Maxim-
Up to 13.5K on the clock - more than 8K ridden since acquisition August 2015, and enjoying every minute of it! Yesterday however, I noticed while riding the shifter felt sloppy, not returning to center with "spring like" action. The gears still shift, but returning to 1st when stopping almost requires me to pull the shifter back up before downshifting again. Before I open her up, just wanted to check with the experts - I'm thinking its the shifter tension spring not torsion springs.

Many thanks in advance. Want to get the needed repair parts ordered one time ASAP!

 

INTERNAL SHIFTER MECHANISM PARTS:

Inside your shifter case side cover are a variety of levers and linkages that translate the motion of the your shifter foot pedal into movements that operate the SHIFTER DRUM, which in turn operates the SHIFTER FORKS which then engage or disengage the various TRANSMISSION DRIVE GEARS. Worn or damaged RETURN SPRINGS can prevent the shifter from operating properly, and are the first thing to check if your bike will not go into gear, is "stuck" in a particular gear, or if you cannot "find neutral".

Of course, there may other issues which could cause the same problems, particularly the dreaded "disintegrating primary chain guide" issue, but it's always best to determine whether a simple problem exists first..........

Pictures of the inside of the shifter assembly can be seen at:

http://xjbikes.com/forums/index.php?threads/20246

and

http://xjbikes.com/forums/index.php?threads/28233


A good write-up on the typical problems and issues involved with these parts can be accessed at:

http://xjbikes.com/forums/threads/xj550-transmission-problem.12233/

http://xjbikes.com/forums/index.php?threads/19227

http://xjbikes.com/forums/index.php?threads/48591

However, please note that the exploded diagram attachment on the 19227 page is "typical" for most XJ-series bikes, the actual mechanisms will differ slightly between different models (the diagram shown in the 3rd post is correct for the XJ650 - XJ900 models; most other models use a variation on the same theme).

NOTE: if this describes your situation:

Couldn't get her out of (whichever gear you were in when the problem occurred).

This situation can be caused wither by a broken TENSION SPRING (the small linear-acting spring) or by the TORSION SPRING (the one with one straight arm and one "hooked" arm). Both of these springs are designed to keep the pawl arm properly engaged with the shifter drum "star wheel" segment. Note there is also a long SCREW which retains this star wheel to the shifter drum; if that screw is loose, it will allow the star wheel to rock back and forth or not even engage with the drum, also resulting in the same type of issue.

On early XJ650 engines and XJ750 Seca engines, the original torsion spring used was somewhat weak, and was replaced by an upgraded spring on later model engines, which also required a slightly different spring collar (sleeve) to be fitted.


NOTE: if this describes your situation:

"Today, after a downshift, the shift pedal would not pop back up automatically."

This problem tends to be caused by a broken TORSION SPRING (the one with straight arms on both ends of the spring) which is supposed to center the selector shaft segment. The earlier 1980-81 XJ650 and XJ750 Seca models were especially susceptible to this problem, and an upgraded, thicker spring (which required a thinner spacer collar underneath) was introduced to the 1982-later models.


Of course, some of these issues may be due to something as simple as broken shifter mechanism but it also could be dues to worn gears (see the TRANSMISSION:section further below for details) or the dreaded "disintegrating primary chain guide" issue, but it's always best to determine whether a simple problem exists first..........

 

Thank you! This quote describes my shifter situation exactly. Broken centering shaft torsion spring the most likely suspect. Since it's the first time this engine compartment will be opened, probably should replace all wear items, since they are 36+ years old. Looks like 3 gaskets ( engine cover and 2 for PCV manifolds which could be left alone but ..while I'm in there) along with 3 springs, one of which I can't locate at this time - the shifter shaft spring (has one hook end). Source for this item, anyone? Any other wear replacements aside from these recommended? Would like to make this a one and done trip. Need to ride, ride, ride! But got to fix, fix, fix first!

Many thanks all in advance.

 

The only things you'll need to get (asid from the broken springs) is a shift cover gasket and a shift-shaft oil seal. Leave the rest of the gaskets where they are. No leaks = no need to replace.

Chacal has parts. Start a conversation with him.

 

Many thanks all for the spot on information, and correct replacement parts. Shifter repairs complete, and like new operation restored. Root cause was indeed a fractured (not broken in half) centering shaft spring. This minor shifter malfunction symptom could easily be ignored, because you can still shift the transmission. The part failure came on very gradually and almost unnoticed, up until the shifter lever suddenly stopped returning to center when downshifting. I wanted to mention since now that I have opened up the engine case enough to see internal lubrication passages, had that spring broken completely in half, a piece could easily have found its way into the oil pan, then up in the inner motor workings, causing catastrophic internal engine damage. Gears chew on oil but metal fragments chew up gears. 50 bucks vs. a post mortem, shall we say.
Riding, riding, riding again! 15K total on the clock now, 10.3K in 14 months of ownership . Loving my little XJ!
Nuff said.