http://4x4mecca.com/forum Post any questions related to off roading or off road vehicles here! en Tue, 07 Sep 2010 03:26:27 GMT vBulletin 60 http://4x4mecca.com/forum/images/4x4mecca/misc/rss.jpg http://4x4mecca.com/forum http://4x4mecca.com/forum/4x4-tech-talk/6169-atf-3-a.html Fri, 20 Aug 2010 14:24:24 GMT Found this info while researching my nieces 97 Caravan transmission problem. Good info for the curious.


For the full story behind the development of ATF+4, please see SAE paper #982674. It is simply packed with interesting data about the development of ATF+4?. Here are a few tidbits:

The initial development was done using Shell's XHVI base oil. Only much later were other Group III base oils approved. (Currently, SK in Korea and PetroCanada are the only additional approved base oil suppliers.) The use of Group III base oils is probably the leading cause for ATF+4 being a more expensive fluid than ATF+3 (which according to the paper uses a Group II base oil).

Lubrizol developed a new shear-stable viscosity index (VI) improver
specifically for ATF+4. The initial tests of this VI improver in the
MS9602 test fluids were so remarkable that Chrysler modified the then-current ATF+2 spec (MS7176D) to include it. Thus ATF+3 (MS7176E) fluid was born; it remained the factory fill until ATF+4. [Lubrizol is still used in ATF+4 and is required in fluids licensed for compatibility.]

In testing done during development of ATF+4, Chrysler noted the following viscosity loss from shearing for the following ATFs (20 hour KRL Shear Test):

Dexron III - 40% loss
Mercon V - 19% loss
Type 7176D - 32% loss
Type 7176E - 14% loss
Type 9602 - 10% loss

You can see what a significant impact the new viscosity improver had on ATF+3 when you compare the 7176D and 7176E numbers. From the standpoint of viscosity loss alone you can see why Dexron III should not be used in transmissions that require ATF+3 or ATF+4. In terms of other basic performance parameters, ATF+3 (7176E) comes the closest to ATF+4, with Ford?s Mercon V a close second. [Which doesn?t mean that Mercon is acceptable.]

The goal in developing ATF+4 was to create a fluid that would match the performance characteristics of the current fluid (Type 7176D), but would retain those characteristics for at least 100,000 miles. The paper specifically notes that the anti-shudder properties of ATF+3 are usually degraded enough by 30,000 miles to cause noticeable shudder.

Contrary to popular myth, one of the stated goals of Type 9602/ATF+4 fluids was that it would have the same frictional characteristics as ATF+3. The paper explicitly states that this was because new clutch materials would not be introduced for this fluid and it had to be backwards compatible with ATF+3. Graphs in the paper show that the friction coefficient of fresh ATF+3 and ATF+4 is essentially identical, but as the fluid ages ATF+4 retains the ?as new? coefficient while ATF+3 degrades.

The paper noted that one alternative was to use synthetic Group IV base stock, which are even more expensive than the ATF+4 solution, which provided Group IV style performance from Group III stock. ATF+4 meets strict low-temperature, oxidation, and volatility performance requirements and relatively low cost ? believe it or not.

Manufacturers can make ATF+4 fluids, but to use the trademarked ATF+4 name in their compatibility list, they must have their fluids tested and licensed by Chrysler engineers, and must use Lubrizol in their formulations. Licensed fluids are periodically sampled from stores to assure quality.

ATF+3
ATF+3 is a friction-modified, high-quality transmission fluid similar to the current fluid in most respects; but it wears out more quickly and has less desirable cold viscosity (to simplify: is too thick when cold). ATF+3 can be approximated by Dexron plus an additive but this does not save much money and is not as desirable as using the correct fluid to begin with.

Dexron itself is the General Motors-specified fluid from far back in automotive history. While it was once the standard for all American autos, that time has long passed, with Ford settling on Mercon and Chrysler on ATF+3 (and now ATF+4); other manufacturers also require their own fluids.

Engine oil has been used as an automatic transmission fluid, again in the antiquity of automatic transmissions; it is still used in manual transmissions, but generally a single-grade oil is used.

The Center for Quality Assurance, which Chrysler uses to run its ATF+4 licensing program, wrote: ?The previous MOPAR ATF+3? formulation was discontinued in 2005 and ATF+4? is recommended for all transmissions filled with ATF+3?.?

Several companies now sell "universal" fluids. If they state that they are compatible with ATF+4?, they may work well, especially for those unsure of which fluid to use. The Center for Quality Assurance warned us to check the label for Chrysler?s license number, and to make sure the fluid is on their list of ATF+4? licensed and tested fluids.

Usage
You can use ATF+3 with all older Chrysler transmissions (except some Jeeps as noted below).

Chrysler is not the only company to require a unique transmission fluid. Dexron has long since passed its prime, and modern transmissions require modern fluids, which more refined properties. Toyota, Ford, Nissan, and other major automakers also require unique fluids. ]]> 4x4 Tech Talk Cricket http://4x4mecca.com/forum/4x4-tech-talk/6169-atf-3-a.html http://4x4mecca.com/forum/4x4-tech-talk/6165-engine-test-run-stand.html Tue, 10 Aug 2010 05:05:59 GMT Howdy all, I am looking to find pictures of engine test/run stands so I can get a good idea of what I would like to incorporate into my own. I would also like to hear any idea's or suggestions from those who have either owned, built or used one of these stands. I will be using it for my current 454 build and possibly 2-3 more builds. After that I intend to donate it to a local school that is still permitted to teach auto shop. (It is barely more than a garage space with a lift and a couple tool boxes but none the less, its auto shop).
I don't want it to be a slam bam thank you ma'am job. Something nice worth putting my time into and that can be appreciated by future user's.
I have taken a look around the web and seen several that have powder coated start buttons (joking of course) and not looking to go real high end but safe, functional, and user friendly.
Thanks in advance for your interest and input, it is greatly appreciated.

Muddi1 ]]> 4x4 Tech Talk Muddi1 http://4x4mecca.com/forum/4x4-tech-talk/6165-engine-test-run-stand.html http://4x4mecca.com/forum/4x4-tech-talk/6164-toyota-h55-transmission-specs.html Tue, 10 Aug 2010 04:53:33 GMT I have an opportunity to buy a h55 5 speed for a project i kind of inherited. Does any one know the max power and torque a stock h55 can take?? I have the fj60 running a chevy 383 im gonna guess makes 400ish hp and maybe 450 ft/lbs. I was told they could take 500 ft/lbs? I have an opportunity to buy a h55 5 speed for a project i kind of inherited. Does any one know the max power and torque a stock h55 can take?? I have the fj60 running a chevy 383 im gonna guess makes 400ish hp and maybe 450 ft/lbs. I was told they could take 500 ft/lbs? ]]> 4x4 Tech Talk k20foxx http://4x4mecca.com/forum/4x4-tech-talk/6164-toyota-h55-transmission-specs.html