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Re: Wouldn't a worn layshaft caused balking when selecting Posted by Cmyles [Email]  (#1126) [Profile/Gallery]
(more from Cmyles) on Sun, 21 Aug 2011 13:44:01
In Reply to: Wouldn't a worn layshaft caused balking when selecting, Larry, Sun, 21 Aug 2011 12:15:59 Members do not see ads below this line. - Help Keep This Site Online - Signup |
Larry,
Theoretically yes but you would need a very great deal of wear to create an angle sufficient to cause actual problems and the effect will be mostly at first gear progressively diminishing as you move to second and so on. For your cluster gear to be angled enough to cause gear gnashing in fourth or third the layshaft would have to lose about 1/4" under the rear bearing AND keep in mind that the front end of the main cluster gear is supported in a much larger needle bearing and the splined sleeve that attaches it to the counter gear which is supported by a beefy sleeve and large rollers. It's not like the cluster gear is living solely at the whim of it's rear bearing. Also, angling the cluster gear will have no effect at all on the function of the synchromesh units so difficult gear selection can't be blamed on a worn layshaft. I've seen cluster gears brush against the synchromesh guide rings but not as the result of a worn layshaft and that doesn't seem to affect gear selection anyway (at least not until the guide ring comes all apart). This all adds up to support the fact that the first thing we always notice is pinion bearing noise even though the layshaft has been damaged, just not enough to cause trouble. I must reiterate that if the unit has been poorly rebuilt all bets are off and anything is possible. In that case you may perceive growling from a worn layshaft but like I said, angulation sufficient to cause noticeable gear gnashing or shifting problems would require that the layshaft be extremely ground down which means that the growling would have to be ignored intentionally using earplugs for a long time. I hear that shifting problems and gear noises are often diagnosed as a worn layshaft but it really makes more sense to indict the; upper chainwheel bearing, clutch hydraulics, pilot bearing, pinion bearings, etc. In fact, I'm starting to believe that probably about half of the gear selection problems that C900 drivers are having can be attributed to clutch hydraulic or pilot bearing defects. Everyone says that the transmissions are the weak link in these cars but the clutch master cylinder accounts for just as much anxiety and just as many posts on this board (I'll bet) and how many guys (and shops) fail to replace their pilot bearing while the clutch is out? A jammed up pilot bearing is giving those poor maligned synchromesh units the finger every time you shift.
Good night and good luck.
posted by 198.233....
, Sun, 21 Aug 2011 10:13:05
1, Sun, 21 Aug 2011 13:44:01 <-- Viewing This Message, Wed, 24 Aug 2011 12:28:50, Thu, 25 Aug 2011 07:51:06, Thu, 25 Aug 2011 11:12:10
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