Reversing Gear Binds When Forward Engaged

[tsaltz]

Last Sunday I was motoring back to my home marina. The forward gear was engaged. I did not believe I was receiving the forward thrust I should. She was not over heating. Soon the engine stopped running. There was a strong rubber or brake burning smell. I checked the engine oil. Level and condition okay. At first the transmission lever did not move into forward easily and would not switch into reverse at all. The shaft moved freely. After she cooled down I was able to move into forward more easily and could force it into reverse. While in the neutral position I restarted the engine. She ran fine in neutral but would eventually get bound up in forward. My impression is that the reversing brake band adjustment changed somehow. My theory is the band became too tight as she was running forward. Is this possible? Maybe the cotter pin came out? Do these conditions fit this theory? I haven't had a chance to inspect the adjustment yet as it was dark when I docked her. Any suggestions?

[Don Moyer]

From your symptoms, I can see why you would conclude that something is binding up in your reversing gear, but we have no historic failure mode that would easily explain how a reversing gear brake band can someow tighten itself.

I think you're on the right track to check your forward and reverse adjustments, and (more importantly) if you can remove the cover over the reversing gear, move the shifting lever back and forth and examine the connecting linkage between the shifting yoke and the brake band itself (and then get back to us). If something really is amiss in the connecting linkage to the forward and/or reverse clutch assemblies, it will usually show up rather easily.

Don

[ArtJ]

is it possible to pull too hard in reverse?

Don
THis may not directly relate to the above issue, but raised the question.
I saw mention in a recent post that it may be possible to damage the
transmission by pulling too hard in reverse. Is this true? Does it
result in a similar problem as with running too long in neutral?

Thanks

Art

[thatch]

Art,
Since I probably made the entry you were referring to I will check in on this problem. In this case I don't think that the roller in the end of the reverse band adjusting bolt is broken but there is another part in the same area that might be bent due to excessive strain being placed on it. The part I am referring to is the brace that holds the upper part of the reverse band in position and could theoretically be bent if too much abrupt strain was placed on it. As has been said many times before, but which bears repeating , there is no reverse "detent" and people often put far to much pressure in the R direction trying to find it.
Another possible cause which fits some of the symptoms nicely would be that the thrust bearing is giving up the ghost. I truly hope not though.
Tom

[thatch]

As I was saying---

tsaltz,
Okay I'm back from the doctor so I can rattle on a little more about your transmission. Since I see that you have a Catalina 30, you should be able to get a pretty good look inside of your tranny. Sometimes it's helpful to reach into areas with a digital camera and take pictures where we otherwise can't get our heads. Several of the parts which may be causing your problem are visible with the top cover removed and can be viewed for reference in the Moyer online catalog section under "overhaul parts-reverse gear/drive train parts". In particular I would view the Brake band adjusting bolt, The reverse gear band, The reverse band brace (which should be flat) and The brake band reversing bar. The reverse gear cross shaft is also pictured in that section, I actually have a bent one in my collection. If it would be possible to send a photo to the forum we may be able to help more.
On a final note, it might be a good idea to have a helper move the shifter through it's range so that you can better see the dynamics of the parts involved.
Tom