Dextron III and IIIH - some Canadian content!
 

I moved this from another thread and added today's shopping experience.

Checked further around our town.
- Walmart had only 1L bottles of their no-name brand, 3.78L jugs of Castrol Import Multi-vehicle for C$27.99 (1L bottles C$8.47) and one 5L jug of Valvoline Dex/Merc for $31.97. No 1L bottles :(
- Went to PartsSource. They and Canadian Tire had the Castrol at an even higher price. But they both had Mobil Super ATF D/M which says it is rated for Dextron IIIH. $27.99 for 5L and $6.49/L. They of course also had a cheaper no-name brand.

Wondered whether Dextron IIIH is same as what we call Dextron III. This link explains what it is:

General Motors Oil Specifications - oilspecifications.org

Doesn't of course tell us if it is good for our old Benzes.

This link does provide some insight and is a useful summary of ATFs.
http://www.cartechbooks.com/techtips/autotransfluid

I ordered Filter kit today and will most likely use the Mobil ATF. (This for my 85 300D)

I pretty sure the motomaster ATF sold at Canadian tire specifies DEX III compatibility. I ran it in all my old benzes.

It does, but I don't want to use a no-name product from CT, Walmart or others in my transmission. Was looking for a name brand. The Motomaster might be OK, but just don't know where they get it from.

They also sell Motomaster 'synthetic' engine oil. But I still pay the extra price for Mobil 1 . (although not much more if bought while in USA). But best to stay away from another engine oil debate :)

I also have an aversion to "no-name" lubricant products (and I consider CT and Wally house brands as no-name), though my rational brain does insist that CT probably would not put out junky oil under their name.

Graham, Wally sells some grades of Mobil 1 motor oil here in Canada way under the highway robbery prices CT charges. I say some grades as for some reason over the last year their supply chain seems to be collapsing, either that or some automotive stuff is no longer central to their business plan. Some grades never seem to be available at all, my neighbor had issues finding 5w30 and that is a very common grade for newer cars.

I just switched to Mobi1 ATF in my '85 and I believe my shifts are now a bit cleaner, by which I mean a tad quicker and smoother.

dexron III-H is the last iteration of the DIII friction modified ATF before GM switched to Dexron VI

I used Dexron III-H in my 1995 (brad penn ATF) and the transmission shifts great - no slip, no kick - good solid surge of power at every shift.

But then I also did use other ATFs meeting Dexron III spec and it shifted great too - when the shifts start to get a bit choppy, I change the ATF.

My rationale was that the w123's were speced for dexII, and since the CT brand atf was speced DEX III, even if it was a lower quality lubricant, it is still probably better than what was originally the w123 from the factory....

I haven't heard that our tranny's are particularly fussy about ATF fluid. Much info on the web, so I relate a few tidbits I recall reading. A main difference of Dexron is it foams a bit, which is intended to keep the inner walls of the transmission clean. I have only rebuilt my 1996 & 2002 Chrysler tranny's which use ATF+4 and they were spotless inside, so wonder that such foaming is needed. I understand that "friction modifiers" actually reduce friction, which is good if you like smooth, slippy shifts, but bad if you want your clutch plates to last a long time. Racers have long preferred "Type F" because it has more friction (F = friction or Ford, unsure). The early Chrysler electronic 4 spd trannys, used in V-6 minivans, suffered failures from shops using Dexron III instead of ATF. It caused "lockup torque converter shudder" and hence fast wear, but ours don't have lockup converters. ATF+4 is fully synthetic (thus more expensive). Chrysler suggests it for all their old power steering now and I use in my 300D p.s. I might use it in my M-B tranny, but last time I added a quart of Mercon VI, based on something I read here. I can't imagine anyone here getting any statistically valid data, unless they work in a M-B shop and service many trannys and get to run long-term experiments.

Horsehockey.

The logic involved this statement is pretty disposable and is basically a variation on much of the "dino" arguments in the synthetic vs. not motor oil debate, the sort of offhand opinion that launches flame wars.

I have been on Mercedes lists since 1995 and driven these cars since 1997. So let me give my version of homespun advice: In those 28 years have never heard anyone say that using Mobil 1 ATF made their transmission perform less effectively, nor that it reduced lifespan.

Incidentally, throwing in the implication that Type F performs better generally is a dangerous piece of misinformation as it has nothing to do with our transmissions.

Likewise, homespun observations from the world of Chrysler also add nothing to the knowledge quotient here.

I am doing my best not to be rude but this is the second time you have posted this exact "information" in the last month and it's bull****.

I used to sometimes buy Mobil 1 there, but Walmart in Kingston has very little of anything these days. They had no stock in stores or on-line of Mobil 1 ATF. Price listed was $74.82 for 6x1L pack. ($14.49/L at CT $86.94 - a bit rich for me :) )

Walmart didn't have the Mobil Super D/M either. At CT $34.48 for 6L (5+1) - Actually bought 7.

For engine oil, I usually buy Mobil 1 when in SC during winter. But our low dollar may change that! Might go to Shell Rotella or Delvac non-synthetics for 300D and buy them here. Don't do much mileage on 300D these days and change oil once/yr regardless.

What is "Mobil 1 ATF" in the "Dexron", "ATF+3, 4, ...", "Mercon", "Type F" world?

People here are smart enough to research on their own. Wouldn't take long to find that racers have long used Type F and that quick, firm shifts let the clutch plates last longer. Designers do the opposite because the public thinks noticeable shifts mean "bad tranny". "Shift kits" have long been sold to rework the valve bodies and discard the springs that make the slow, slippy shifts that cause wear. I put some in my cars.

Can you relate anything technical about M-B tranny's to help people here or just rant "must be different"? Don't they use clutch plates (i.e. paper on steel) like all legacy auto trannys (not some of the latest designs). I think the main difference with the Torqueflite design of my Chryslers is how the shift controls work (centrifugal speed sensor vs intake manifold vacuum signal like old Fords). I do have an M.S. in Mechanical Engineering and have rebuilt 2 of my trannys, but doesn't mean anyone should listen to me or that most of what I say is correct. Read, think, and learn.

I doubt I will ever rebuild a M-B trannys since the "banner kits" are $400 vs $50 for my 60's Chryslers. A better question is why bother trying to maintain these cars with such crazy prices.

Doesn't type F have some sort of high friction grit in it? I seem to remember reading somewhere that it was only supposed to be used in very specific Ford transmission and nothing else....

Wikipedia is your friend, https://en.wikipedia.org/wiki/Automatic_transmission_fluid .
It says that Type F isn't more of something, rather less, i.e. contains no "friction modifiers". Interesting that even some GM's had shudder problems from various Dexron's. BTW, these modifiers are more complicated than just a different "friction factor", some have "non-Newtonian" behavior like slipping until they grab suddenly. Interested people can read many engineering papers on that.

More info, some from the hot rodders angle:
I found this info on ATF about Dex Merc Type F Type A. Thought Id share. | The H.A.M.B.
Type F in powerglide? | The H.A.M.B.

or don't read these and listen to Zacharias.

Heck of a thread for me to stumble into while trying to find the correct transmission fluid for my 84 300SD.