one thing about the mazda tranny it is not a good dailly driven tranny[ on free way ] when in 5th gear it draws all the fluid to the back of the tranny and burns up the front gears. it is stronger then the mitsu. the mitsu doesent have that problem but its not as strong.
I'll just Say "Huh?"
How the hell did you come up with that?
The gears all spin the same way regardless of what gear you are in.
because the gears are "constant mesh" the only thing that changes is which gear is locked to the output shaft (though technically 5th and reverse lock onto the counter gear the gears they drive are SPLINED to the output shaft already)
The only difference between the Mazda that the OP has in his truck and any later one are the incremental improvements, the better 5th-rev synchro setup, and of course the "wide ratio" gearset the 2.9 version of the trans shares with 4cyl and 3.0 installations.
I'm currently running a "wide ratio" trans behind my 4.0.
That transmission has made TWO round trips to Wyoming since
September of 2007
Oil starvation parts failure issues in the mazda trans are related to either
overboard oil loss (common and NOT specifically related to the famous "rubber plugs" though they usually get the blame)
OR pices of the plastic shifter bushigs that fall into the trans,
get ground up and eventually plug the small oil feed passages
to the "pocket" bearing.
when the pocket bearing burns up the heat generated destroys
the heat treating of the input gear and the gear basically melts
like a Hershey bar left in the sun
There are two distinct areas where 4.0 transmissions could be considered "Stronger" than the 2.9 trans.
One is that except for a very few VERY early 4.0 transmissions
(the first half of 1991) got the weaker "fine spline" 5th Reverse synchro setup, but the likelihood of finding one of those transmissions still in a vehicle is small, most got overhauled and "upgraded" long ago. it's an "upgrade" shared by
ALL 1992-up mazda's regardless of what engine they were for.
the other upgrade is the way the reverse idler shaft is mounted
to the case, the later case (all 4.0 cases) the shaft is better supported by a heavier reinforcement boss that "cups" the part of the shaft where it is bolted to the main case.
But again, that change was also applied to all 4cyl and 3.0 transmissions as well.
I've seen ONE trans broken that way.
as for the strength of the actual gears? No.
I'm almost convinced that the 3rd gear for the 4.0 transmission is slightly weaker than the one for the other applications because the smaller diameter of the gear required ford to use a smaller diameter inner sleeve (located the synchro dog) that is TIG welded to the gear itself in the manufacturing process
the actual perimiter of the weld is smaller and the parts thinner so they tend to use less current in the welding (to avoid heat dammage) and in the process they get less weld penetration
I've seen several 4.0 3rd gears where that weld split.
I have yet to see a similar "wide ratio" gear split even if those gears are assembled into a transmission case that will bolt
to a 4.0
As for the proper oil? Dex3 is the correct fluid UNLESS you have a trans late enough to have the "plastic" coated (inner friction surface) synchro rings that are DESIGNED to be used with Mercon5.
My trans does have the "plastic" synchro rings and I still run Merc3 in it.
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