Transmission Fluid Question (long)

[Lawrence Weeks]

Once upon a time (Sat Feb 16), Jason Davis wrote:

> Then he says that I don't even need to change my fluid, even
> though he never looked at my car. He claimed that if you change the
> fluid after about 40k miles, it can screw up your bearing pretty
> bad. The "harsh detergents" in the new oil will "over-clean"
> my transmission. Does this make any sense? I'm too much of a
> neophyte to tell. Could there be some kind of correlation between
> new transmission oil and the 5th gear pop-out?

Others have answered the GL-4 v. 5 point. I'll talk about this. First,
it sounds like he doesn't know the difference between an automatic
and a manual gearbox. You can try educating him, but probably
not worth it. What he said about changing fluid may be true in an
automatic. In those, changing the fluid at higher mileage can damage
the transmission, as the worn clutch material can be dislodged by the
detergents, clog up the works, and mess up the tranny. I experienced
this firsthand once, and spoke with numerous auto transmission guys
afterward about it.

Next, there is no correlation with 5th gear pop-out. That is caused
by a physical issue. Nissan modified the 5th gear synchro to wear
better, and that change appears to have solved the problem. Speaking
of which, I took apart my 1992 tranny with 160k miles, and it has no
wear whatsoever on fifth gear.

Larry
--
Lawrence Weeks      "Audaces fortuna juvat."      dev@deskmedia.com