jon@dakota-truck.net wrote:
> Indeed. I don't recall what year the changeover happened
My 01 Ram with a 46RE uses ATF+4 factory fill... I think it was around
2000, 2001 that they changed.
> but if
> your factory fill was ATF+4 then you should definitely be using ATF+4,
Yup, factory states any trans factory filled with ATF+4 must use ATF+4
only and no prior versions of ATF.
> however, as Ray said if its been ATF+3 all along, you can keep using
> ATF+3.
Good luck finding any ATF+3. NAPA and AutoZone no longer stock ATF+3.
Last ATF+3 I was able to buy I found at Advance Auto, about a year and a
half ago. Havn't checked to see if they still have it, or if anyone
else sells it anymore. Even Walmart has ATF+4 - and they even have an
actual Mopar Brand ATF+4 fluid, bottle is identical to the dealer fluid.
Don't know what is actually in it...
>
> Note that although ATF+4 is claimed to be backwards compatible with
> the earlier ATF+3, +2, etc. it is known that it will attack certain
> seals in earlier transmissions. (The trans will still work, but it
> will leak.) Unfortunately I don't know what type of material those
> seals are or what transmissions they might be found in, or how far
> back we are talking, but this is something to be aware of. If you're
> using ATF+3 now, I don't see any real reason to switch to ATF+4 unless
> you're planning to take an around the world trip and/or never change
> your tranny fluid again, especially when you consider the price
> increase. (I believe ATF+4 is fully synthetic so that probably
> accounts for most of the price difference.)
The leaking issue with ATF+4 in older ATF+3 transmissions is more to do
with the age of the seals in the trannys vs. the fluids "attacking"
anything. There was lots of stink about this when ATF+4 hit the
roads... I ran this past the Valvoline product rep. at a product seminar
last year and what I learned was interesting. The various blends of oils
on the market actually do have specifically designed applications in
mind. Without going into a lot of detail... basically all the engine
oils start out with the same base stock material. THey recieve specific
additive packages depending on their intended use. "high milage" oils
are blended with seal "swellers" and conditioners primarily... to help
aid in oil control for older, worn engines. I pegged him on just why
someone who was running conventional oil for say, 60K miles... would not
want to switch to synthetic oil. The way he told it was the synthetics
have much better cleaning properties and will retain (suspension)
contaminants better than conventional oils. The side effect is that
when engine sludge and oil deposits build up around seals and gaskets,
and you dump synthetic in, and it starts cleaning the deposits up...
leaks can start. Seems to make sense to me. When I bought the Ram, it
had 30K miles on it and the first thing I did was change the oil and
dump Mobil 1 synthetic in. Within 5000 miles the front timing cover
seal started leaking. I was lucky and skated in under the end of the
factory warranty and had the seal changed. The reason I typed up all
this? As was pointed out, ATF+4 is synthetic (Bernd says its
semi-synthetic - guess it doesn't matter) - its cleaning properties and
its additive packages to allow longer maintance intervals, will cause
older transmissions with miles on them, to start to leak more.
Seal technology did not just change over night when ATF+4 was blended.
(if someone has info to support that the ATF+4 transmssions use new seal
materials than transmissions that used ATF+3 - I'd love to see it! :D I
don't think the seals are "attacked" by anything. And as someone else
stated that ATF+4 "attacks"the metals in older transmissions - sorry my
friend... thats just pure incorrect information :)
>
> Regarding switching to ATF+4 in order to extend your fluid change
> intervals, this sort of thinking always makes me a bit nervous, like a
> synthetic oil giving you 10,000 mile oil changes. If your engine is
> *designed* for 10,000 mile oil changes, maybe, but every engine is
> different and the oil will pick up contamination from blowby, the
> outside atmosphere, etc. No oil is going to be able to do anything
> about foreign debris floating around in it. I think that's the main
> purpose of a fluid change, not so much to replace a "used up" fluid,
> as to flush out the crud that has been picked up.
>
We're using Royal Purple oils in our Chevy Colorado 4 banger delivery
trucks, and told to go 10,000 miles for an oil change... yeah that kind
of rubs me the wrong way... but hell, they arn't my trucks - and they
are Chevys. What do I care if the engines seize heh. However - I have
switched both the Ram (now at 66,000+ miles) and the Explorer (at
48,000+ miles) over to Royal Purple, from Mobil 1. I plan to run 5000
miles on an oil change, with a filter change at 2500 miles. I'm going
to send in oil to Blackstone on this round of oil changes to see how
this oil change schedule will work out.
Catcha folks later - I have the weekend off after having worked 12
straight days of hell. I'm going to go hide in the woods and chop trees
and fish and piss off the campers down the road with some Rob Zombie at
4 in the morning...
-- ------------------------------------------------------------ The Zen philosopher Smasho once wrote: "A truck with no dents, is not a 4x4... and a 4x4 with no dents wasn't at a DML BBQ" ------------------------------------------------------------ three busted-ass daks, a gas hog, and a rollerskate http://members.aol.com/silvereightynine/ AIM & Yahoo: SilverEightynine ------------------------------------------------------------
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