No longer going to support the 3 speed...

[1988GTU]

As some of you may know, I was a believer in the durability and reliability of the 3T40 slushbox . With almost every attempt in making it into something that it just is not cut out to be I am cutting my losses with that piece of scrap . It's a fine DD trans for the stock application vehicles it came in and can handle a lot of abuse as long as the abuse isn't more torque/horsepower being thrown at it, but really hows that any fun!?

In the past I've went through more 3 speeds than I care to remember and I can tell you all of them were supposedly built by someone that "knew" how to make it "bulletproof". After a lot of disappointment, I soon started building my own and used nothing but best of the best that I could get my hands on . With a lot of research and one off parts I realized that this bulletproof trans was just unobtainable keeping me from greater achievements . With my quest of a "bulletproof" trans I often was prompted with the 4t60/65 suggestion, but that suggestion just was not something I was looking to hear/read for many reasons that I will not explain since most that know, know the reasoning's .

The first sign to this misleading theory that the 125C/3T40 was not a performance capable trans was when I started approaching 350hp/tq numbers and started ripping through these transmissions like a fat kid in cake . When the power output increased more, it failed a lot quicker and would just fail right on the rollers . Over time, I've used a few coolers, in which some were suggested by local FWD specialist and it just didn't cut it. My temps were ideal, normally. However there's a point in which power over comes heat and friction surface was not proper for what it should be . The only item to live through this was EP's LSD... But it really cannot fail when the part behind it stop moving before the plates and springs can do there job.
Of all I went through with these transmissions, I can say that I would rather pull the engine and trans together than try to drop the trans out the bottom.

After doing a clean up of the parts I managed to snap a few pics of some parts prior to pitching...

Enjoy the carnage and random parts that survived (This trans was only in for a couple days and run time was less than 10 hours... most was of the time was idling or cruising ) :








I have one trans in mind that I am going to give a try...AND NO IT'S NOT A MANUAL TRANS!
Starting early May I hope to have the trans I need and all the parts to put in it to be ready by June . After some research with reality on mind, I feel confident in my next choice.

I know I am leaving a lot of other info out that I am just forgetting to post up, but really its nothing positive.
One thing I hope to save someone later on in their projects is the grief that I went through trying to make something into something it just cannot be.

[weba]

I have one trans in mind that I am going to give a try...AND NO IT'S NOT A MANUAL TRANS!

My 0.02€: Blah, Even if you get it working with your new setup, it's almost none of the fun what proper transmission offers, such a shame

[Wanako]

I have one trans in mind that I am going to give a try...AND NO IT'S NOT A MANUAL TRANS!

My 0.02€:

I found this amusing for some reason.

so what are you planning then? 6T70?

[1988GTU]

I have one trans in mind that I am going to give a try...AND NO IT'S NOT A MANUAL TRANS!

My 0.02€: Blah, Even if you get it working with your new setup, it's almost none of the fun what proper transmission offers, such a shame

LoL..... oh and isn't your countries currency higher?

[1988GTU]

so what are you planning then? 6T70?

You'll just have to wait and see.

[3X00-Modified]

What clutches were you using? Did you play with the valve body or up the line pressure? Without proper pressure readings and or bump in pressure then yes the clutches will slip all the time.

I still have to take mine apart to see if I had any issues with my last 12.67 run, but the only time I had clutches end up looking like that was when I put a C-clip in the wrong spot which prevented a clutch pack from disengaging when it went into OD which then yes burt the input pack to crap.

Honestly the only problem I see here is apply pressure and clutch material... I think that could be solved.

[MY91GT(Z)]

what do you have done to your car that your blowing these trannies?? is your car turdbo or something? to bad asylum is no longer on here as he has had the best 3t40 built thus far

[3X00-Modified]

He's turbo'd and Asylum has an OK 3t40 that is built to support possibly 220-250 n/a hp... 1988GTU is beyond that point.

[1988GTU]

The failure was from most likely shock impact. Which resulted in the "cupping" of the clutches and waves. This last trans was my last try at using a 3speed. For that last build, I had Eric aka Asylum trans guy build it. With Eric not responding to this issue I am forced to give up on this trans and am out my money invested. So to know what he exactly did to it and what was supposed to be done... it should have had proper pressure and correct parts installation with other "tricks" done.

The clutches I'd hope to be reds or better.

[3X00-Modified]

I had the same cupping issue as you and there is also at least one wavy disc per pack IIRC.. And mine was a straight up slip issue which then caused all that damage by slipping as much as it did... I think I did 5 miles and I did a good job on them. So it could have just been slip. I'll have to find a close up pic of my red's so you can possibly check yours to see if thats what they were.

here's mine.





Those are hanging on my garage wall as a reminder to double check my work before closing things up... The first kit I bought to get the red clutches was close to $400 bux, I'm so glad I found the same clutches on WITTRANS.com for $155... Never buy from Level10... RIP OFF!

[1988GTU]

One thing that was really toast was the housing and drum assembly ... it would not separate.

[1988GTU]

I'll have to view it when I am at home later. Thanks for the pics.

[3X00-Modified]

btw.... What fluid were you running? I had Dexron VI in mine and Jeff is saying thats why I'm having so many issues with my EP LSD... He's telling me to use Type F or Dex III I don't mind using Dex III but I had a bad time with type F once and like 4 parts died in my trans so I don't want to touch the stuff anymore... Granted it could have been a possibly lubrication issue or due to it being my first trans built but I'm just leery of it... Just like getting sick on alcohol, you tend to stay away from what triggered you to vomit... LOL

[1988GTU]

I used Royal Purple full syn. 8.99. MY cost per quart.

[3X00-Modified]

See now I was told that the full Synthetic was my problem... WTF... I think I just overpowered the LSD which caused it to start slipping and it just got worse, and aparently I'm the ONLY one who has ever had a problem with his LSD's...

I'm going to go back to Dex III to see how that works out.