The Ultimate Transmission Thread... Brainstorm Ideas Here!

[95PGTTech]

Take a look at MTX-75 internals and then to our G25M tranny internals and you will notice they are completely different.

we've pretty much established that our M5 transmission is basically a re-worked MTX-75 with a different case. gears 1-5, R are interchangeable because they are equal dimensions and cut (helical), but the final drive (differential) won't fit into the case without severe grinding.

in order to change that differential we have to go aftermarket or find a way of fitting the entire MTX-75 (the case) in our cars.

[Gro Harlem]

and I find it funny that ford recommends you use ATF instead of the proper 75w80 in their mazda-sourced transmissions.

its almost like they want them to fail so they can azz-rape people at the dealership for tranny failures.

[Fastest95PGT]

and I find it funny that ford recommends you use ATF instead of the proper 75w80 in their mazda-sourced transmissions.

Maybe it's to give the MTX the same life expectancy as the ATX.

[95PGTTech]

its almost like they want them to fail so they can azz-rape people at the dealership for tranny failures.

I doubt that. Ford, the dealerships, and the technicians all make very little money on swapping in and out a new transmission. There's usually a specific technician at a Ford dealership that works solely on transmission, differential, and drivetrain issues (you can usually tell who it is because they're usually the grumpiest with the shortest temper). They usually make more in M time than in actually working time.

It's like saying the dealership gives you bad oil so you have to come back for more frequent oil changes. The dealership, and the technician, lose money on an oil change.

The only reason you're probably thinking you're getting azz-raped on the transmission is because the bottom $ line for the customer is a big one. Transmissions cost a lot, who would have guessed.

[jonboy192]

we're getting off topic, but it's commonplace to use ATF in a manual tranny, it's no big deal...really.
jonathon

[95PGTTech]

Hey, just as another $.02 of mine:

Rather than do the Mazdaspeed LSD rebuild, there is an LSD for our M5 transmission (other than the extremely expensive Quaife unit). CZT is offering an LSD kit, appears to come with 4 spider gears, 2 axle drive gears, better than stock input shaft, LSD, 4.6 final drive ratio.

The only problem I find is the 4.6 final drive ratio (versus 4.388 stock). I would rather have the stock final drive. They apparently didn't account for the guys rebuilding their transmissions themselves because they just use a shorter final drive to tighten up the shifts.

I would personally have a final drive around 4.1 or 4.15 so that I can choose my own gearing and have 1, 2, 3, 4 be REALLY short. The short 1-4 combined with the long final drive should keep the gearing decent for the power level I plan on (at ~300WHP, it will seem really short...good for the track). Then I can chose a huge 5th and that, combined with the final drive, would be great on the highway. Add to that my 18's and I want 35mpg.

I am going to contact CZT and see if they offer any other final drive options. I doubt it.

[rurockn]

Rumor was that the reason the CZT kit requires all of those parts to work is that they are all OEM parts from another vehicle... but which one was the question? Another rumor was that some Honda transmission used the same final drive pinion and spur gear dimentions as well as all diff. dimensions just different spline outputs for the cv's. No one ever tried anything, but it was noted that on the CRX uses the same "spider" kit as the Probe and Escort. Kinda interesting.

I agree though, I would never want the 4.6 final drive. Its bad enough as it is running out of 4th gear at the end of the 1/4 mile, and cruising on the highway sucks running 4krpm@80mph. Ideally I would just want a first and second gear combination that actually MATCHED. I could stay with 3,4, and 5 and not complain.

[95PGTTech]

Rumor was that the reason the CZT kit requires all of those parts to work is that they are all OEM parts from another vehicle... but which one was the question? Another rumor was that some Honda transmission used the same final drive pinion and spur gear dimentions as well as all diff. dimensions just different spline outputs for the cv's. No one ever tried anything, but it was noted that on the CRX uses the same "spider" kit as the Probe and Escort. Kinda interesting.

I agree though, I would never want the 4.6 final drive. Its bad enough as it is running out of 4th gear at the end of the 1/4 mile, and cruising on the highway sucks running 4krpm@80mph. Ideally I would just want a first and second gear combination that actually MATCHED. I could stay with 3,4, and 5 and not complain.

yeah I heard those rumors too, but never saw any external links. Nothing credible to back it up, just PT member opinions, which, as we know, are usually 85% wrong and 90% not reliable.

I figure even if they did rip OEM parts from other cars, they still had to do a lot of machining and fabricating I bet, plus with the cryotreatment and everything, I figure let them make the very few bucks they make on it. I mean, even if it is OEM parts from other cars, the machining and cryotreatment really make the sale. We could track down the OEM parts, but we have no one who could do the machining and fabricating who wouldn't charge for it, and the cryotreatment is probably 85% of the reason the transmission is stronger. I mean, these are the guys who are doing the CZT IM that supposedly put 5-6 WHP over stock without the VRIS on an N/A application. I doubt many people on here have the knowledge, tools, or balls to stand toe-to-toe with CZT and build that trans.

[rurockn]

I doubt many people on here have the knowledge, tools, or balls to stand toe-to-toe with CZT and build that trans.

I'd put my reebok soft tips up against theirs. Especially if I wasn't so busy remodeling.

[Smuffy]

and I find it funny that ford recommends you use ATF instead of the proper 75w80 in their mazda-sourced transmissions.

its almost like they want them to fail so they can azz-rape people at the dealership for tranny failures.

Would you really be so surprised? You wouldn't imagine the horror stories I've heard belonging to other forums. Like new Explorers coming out of the factory with under a qt. of fluid in the rear end. Then getting sold that way. Then dealers saying things like "just hope they last through the warranty period". I haven't had much experience with Ford(I've only been buying cars for about 6 years) but between the things I've seen and what I've heard from friends who have worked for them or been screwed by them. I will NEVER trust a Ford dealer farther than I can throw his greesey ass.

[duffbuster243]

That's entirely possible. But we're not talking about huge amounts of weld or anything. As a safety precaution (primarily due to your old threads ), I had my diff pin cryo'd so I'm not very worried. I welded both ends so it's not sliding out without a fight and I'm confident with it's strength to hold together while in place. Look forward to my upcoming "my diff broke" thread in the spring.

Why would you remove the pin before the diff was destroyed? If I wanted to sell the PG I'd probably sell it inside a working diff for more as the spider gears are already ground.. then pick up a spare diff out of a tranny with bad synchros.

Everyone else I have spoken to says that the sheer pin broke and the diff pin began to slide out one end.. once one end is inside the diff the gears tear it apart. Are you saying that the pieces of your diff showed that one end of the pin was still in place with the sheer pin holding it?.. if not, I'd suspect my description is likely what happened.

i can back this up i took my old tranny apart that i stripped the differential gears on. upon inspecting the differential i noticed a slight crack in the diff right where the shear pin is. my belief is that under a lot of pressure it cracks right there and the shear pin either breaks or works it way out due to less pressure holding it in from the crack around it. i can show pictures of the diff and the crack if anyone is interested. i believe slightly welding the pin in is the easiest fix and i think the diff would prolly be pretty rigid with this done. but maybe somebody can come up with some better alternatives.

[rurockn]

Would you really be so surprised?

** *** **** * ***** ** *** its because many cheaper gear oils have very strong solvents in them that can eat away at seals and/or bronze/brass parts inside the transmission. Ever noticed that Honda recommends 10w-30 petroleum engine oil for their transmissions? Some Nissan's recommend 5w-20 or ATX. This is the same reason that when sulfur's were first introduced into gear oils in the 70/80's people had so many seal problems on their older model cars with 100% rubber seals. Sulfur ate away the grime at the surface that had built up over the years and made it to the old seals surface which had worn, and leaked. Ask any old Muncie or Rock-Crusher guy and hell tell you about leaks.

I wouldn't weld the pin in because it would cause even more stress localization in that area... unless you had someone heat treat/stress releive the whole diff afterwards.

edit: no reason to be so harsh

[95PGTTech]

I'd put my reebok soft tips up against theirs. Especially if I wasn't so busy remodeling.

I know what you mean, but even I, with Ford behind me and an awesome machine/performance coating shop, wouldn't even dare.

Simply because they lose so much in R&D. If I could compete with them, you'd see Chris Reiser Motorsports.

But yeah, showing respect for CZT.

especially since they have the larger g-Force Auto as their parents.

[turbo_KL]

M5 transmission is basically a re-worked MTX-75 with a different case. gears 1-5, R are interchangeable because they are equal dimensions and cut (helical), but the final drive (differential) won't fit into the case without severe grinding

Need to put an end to this MTX75=G25M crazyness :-)

Did you had both gear sets in your hand, disassembled them and changed gears between them. I suspect no.

http://www.sportcompactcarweb.com/pr...0205scc_focus/

Notice how the 5th gear placement is inside the case. Where on F,G,H Mazda trannys it is on the otside under a separated cover.

The input and output shaft are completely different from G series.

It is like claiming Mustang and RX-7 trannys are the same just because both are RWD and Mazda and Ford work together.

[Fastest95PGT]

Need to put an end to this MTX75=G25M crazyness :-)

Did you had both gear sets in your hand, disassembled them and changed gears between them. I suspect no.

http://www.sportcompactcarweb.com/pr...0205scc_focus/

Notice how the 5th gear placement is inside the case. Where on F,G,H Mazda trannys it is on the otside under a separated cover.

The input and output shaft are completely different from G series.

It is like claiming Mustang and RX-7 trannys are the same just because both are RWD and Mazda and Ford work together.

It's been confirmed! I'm so excited!

Time to go inform my RX-7 and Mustang buddies too.