5th gear snap ring (Not popout problem)

[Lawrence Weeks]

Once upon a time (Sun Oct 20), Thomas Reynolds wrote:
> Larry wrote:

>> Looks like the input shaft has wear from the clip
>> being shoved up.

> My father and I are quite amazed that half actually stayed on the
> shaft as it had nothing to keep it there.

It looks like it goes around a bit more than 180 degrees of the shaft,
so I'm not that amazed...

>> I'll wager that it was simply a re-assembly screw-up in the past,
>> no big mystery. No other explanation really for the snap ring
>> being out of the groove.

> After discovering immediately afterwords that others had this
> problem, I really think it is a Nissan engineering issue. If
> my failure was the only ever known, isolated from anything even
> remotely common, then I would still say that it was a fluke weak
> snap ring or an assembly SNAFU.

I think assembly SNAFU. That clip can be a pain to remove and
install. It goes in there really tight, and that groove is about
50% of the width of the clip. I just have a really hard time seeing
that clip being opened up enough by some mysterious force to come
out of the groove and ride up the shaft. It is very clear from the
picture that the clip was on the shaft, and not moving much if at
all, while the shaft moved, hence the obvious scoring damage. That
indicates that it was there for a good length of time.

I bet that when Nissan put it together, they didn't get the clip
seated in the groove completely. Likely one half of the clip was
in the groove, and over time, it was worked out by the rotation of
the shaft v. the rotation of the stopper. Just like when you run a
screwdriver under a clip that has been partially removed and it lifts
the rest of the clip out of the groove. Looks like you got a Friday
transmission.:-(

Regarding what you said about there being a race on the input shaft
that can be replaced, I do not see that on the shaft I have. You may
think that because the shaft end is chamfered, and the shaft surface
is plated/polished.

>> I bet that it broke after being trapped between the stopper and
>> the bearing, though. I still would wager on assembly error.

> Ah so you mean you believe it popped out of the groove long ago
> unbroken and under stress of pressure and friction and heat it tore
> it in two. Hrrmrmrmm....... Interesting.

Indeed. What is the nature of the breakage of the clip? Is it a
smooth break, ragged? Does it look stressed? How does it feel to the
fingertip? Does your skin get caught? What is the condition of the
metal directly behind the break?

Regarding your transmission overall, with the damage to the input
shaft, the damage to the case, perhaps you should just get a used
tranny, open it up and give it a refreshing if necessary, and use that.

Larry
--
Lawrence Weeks      "Audaces fortuna juvat."      dev@anabasis.net