🚀 go-pugleaf

On 8 Apr 1997 09:05:50 -0500, faught@convex.hp.com (Danny R. Faught)
wrote:


>
>While I can't vouch for the validity of his offer, I can say that I've
>heard of this idea before.  I don't recall for sure which engine fluid
>it was, but I have been told that changing it after it was left in far
>too long could make some major repairs necessary.  Probably would
>disrupt some internal valves or something that are already on the
>brink of falling apart.  I guess the bottom line was that we could
>have gotten the car to last a little longer very cheaply, but would
>have to junk it when it does break down.  What actually happened?  The
>memory is dim, but I think we opted to leave it alone and take our
>chances, and it limped along for a while.
>-- 
This hypothesis is presented in the case of automatic transmissions.
Basically, some will claim that if you have not made regular fluid and
filter changes at the manufactures recommended intervals then you
shouldn't do it at some arbitrary milage of say 80,000 or 100,000
miles. Their premise is like you have suggested that some valves are
only seating against the grime that has built up and that the fiber
clutches are so worn that the contaminated fluid enhances their
ability to transmit friction. See rec.autos.tech for a better
exploitation and arguments if you are so inclined.

I tend to believe that if a fluid change kills your transmission then
it was already dead and by leaving the dirty fluid in you will only
induce wear to other parts of the transmission making a rebuild more
expensive. Others disagree so like I said a Deja News search of
rec.autos.tech will give you plenty of information to base a decision
on. 

Having said this, a automatic transmission and a motor are entirely
different beasts and motor oil and transmission fluid serve different
roles as well. While the theory that dirty transmission fluid might
let you get a few more miles out of a worn out transmission is
certainly subject to debate, (although IMHO is dubious information)
anyone who would put forth the same argument for an engine is severely
misinformed and in violation of the First, do no harm rule. Dirt and
friction will kill an engine fast and when an engine dies from bearing
failure the results are usually spectacular and expensive.

Rick