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T56 experts PLEASE step inside

Discussion in 'Driveline' started by turbov6joe, Aug 30, 2015.

  1. turbov6joe

    turbov6joe Defensor Fortis Established Member

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    Ok....I'm going to keep this thread as short and to the point as possible, but I need professional/knowledgeable info immediately.....with that said, please allow me to thank you in advance.
    Right to business: The T56 in mention is in my 2003 Cobra, and to the best of my knowledge has 60,103 miles on it. The previous owner did the anti-venom mod, 26 spline input shaft, MGW shifter, and bolted it back up with a Spec 3+ clutch and a Fidanza aluminum flywheel. It also has a Ford Motorsports adjustable clutch cable and quadrant. About 500 miles ago I began noticing that the shifter was becoming increasingly more and more difficult to get into first gear when sitting stationary after the tranny was hot....I would always have to put it into a few other gears to finally get it into 1st. Once moving the shifting wasn't really anything out of the ordinary for a T56, and as far as speed shifting smoothly (or not so smoothly into 3rd gear). Tonight heading to a car show it got rally bad.....bad enough that I spent a good amount of time mucking with the firewall adjuster, and actually got it set correct enough that it would slide into 1st gear smoothly while at a stop.... as well as the other 5 gears. However, at the end of the evening, while backing out of a parking space that was on a slight grade, I noticed a violent shudder in the tranny....this happened 3x's tonight. Along with the shudder is a loud rattle/clunking noise with bad vibration...it feels like a shaft with reverse on it is terribly out of balance and/or bent. The forward 6 gears seem to be working just fine. As a side note, earlier today I drained the royal purple lube that was inside of it, and replaced it with new clean fresh Dex/Merc III (4.8 quarts). Before something inside takes a real shit and really causes catastrophic (more expensive) damage, I am going to pull the tranny and have it rebuilt. This is where I need the expert opinions as to what MUST be addressed, and what SHOULD be addressed while it's apart. I would like to strengthen it some, smooth the shifting out if possible, and generally make it able to live behind my 643 WHP motor for a while. The car sees limited drag strip duty anymore since our track closed....so all abuse is from the MT drag radials on the street. PLEASE be very specific on what to do or what part you suggest and why it's recommended. I don't have an unlimited budget , but I don't want to cut corners either. Any help will be greatly appreciated. If anyone knows of a top notch tranny builder in Kansas or the surrounding states, send me their contact info.
     
  2. bubblehead93

    bubblehead93 Member Established Member

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    noise in reverse but not other gears is likely in the tail extension as reverse and 5-6th can be found there. The reverse idler gear is on its own shaft and could account for the issue to only occur in reverse (though little pieces might be moving around which may find their way elsewhere. The shaft for the reverse idler gear is held on one end by a bracket with a bolt. I can't remember which side it faces (extension or main housing). I'll see if I have any pictures that show it. I'm not sure the two problems (tough 1st gear and the noise in reverse) are related. The former sounds like tired synchros. The later sounds like a problem in the tail housing.

    r/
    Andy
     
  3. bubblehead93

    bubblehead93 Member Established Member

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    to answer your question while you have it apart, replace all of the synchros, billet keys (I did every synchro, 1-2, 3-4, 5-6, once you see the stamped ones you won't want them anywhere in your transmission, the MUST would be 1-2 and 3-4), bronze shifter fork pads (again all, did reverse too if I remember correctly, again plastic has no place in my t-56, MUST would be 1-2 and 3-4), and a bronze shifter cup. While I had it apart, ground down all of the parting/casting lines in the case (remove stress risers). I would also verify that the input shaft was properly shimmed when installed (by whoever did it before). I'm a 525 hp guy so I can't speak personally for 650 hp but I think this would work for you as well based on what I have read of others and your stated application. I drag race and auto-cross mine, 4k clutch dumps on the 2-step is a fact of life...

    r/
    Andy
     
  4. MG0h3

    MG0h3 Well-Known Member Premium Member Established Member

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    I was going to say that you are having a clutch problem.

    If you had only said you got the noise in reverse, I would focus there. But it seems that you were able to manipulate the problem by adjust the clutch.

    Are you sure the banging wasnt just severe clutch chatter?
     
  5. turbov6joe

    turbov6joe Defensor Fortis Established Member

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    Andy,
    Thanks for the detailed response, your suggestions seem to mirror others as well. What's your opinion on doing the 31 spline output shaft and the compressed carbon blocking rings? Is there any chance of smoothing out the shifting by doing these aforementioned mods? With the suggested mods, what kind of max power do you think it would be capable of holding up to? I see all sorts of ads for the T56 magnum and the "Viper spec" T56. What do these trannys have that makes them so bad ass and 700+ lb-ft capable??? What do think the cost range would be to do what you suggested?
     
  6. turbov6joe

    turbov6joe Defensor Fortis Established Member

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    I'm not so sure it's not chatter after all....it seems very coincidental that all the problems (chatter) happened after I adjusted the clutch quadrant out so it would go into 1st gear easier. Along with making the adjustment I also drained whatever purple fluid the previous owner had in there, and replaced it with Dex/Merc III. The first time I drove this car, I never really loved where the clutch released at....it was really high. I've played and played with adjusting the quadrant to find that "sweet spot" where the clutch would start to release about 3" or so from the bottom. I've been very cautious about not over powering the clutch when adjusting it so to avoid any slipping concerns. It seems like once the Spec 3+'s get slipped real badly they are never the same. When I bought the car the owner told me that the Spec had about 2000 street miles on it, and these were only ever with OE size street radials that didn't have much stick to them. Since I've owned the car I've only launched it from a dig 1 time with the MT drag radials and they hooked real good. Typically I don't beat on it from a dig because I don't want to break half shafts at this time. Since I'm in the middle of a Fox notch restoration, all my extra $$$ has been funneled to it. What's really odd is that the night I made this post, I had just gotten home from the car show after an hour ride and a few 3rd gear punches racing my dad in his Terminator. When I backed out of the lot it chattered real bad, I didn't think I would get the car up the grade. When I got home after a 35 mile highway run and pulled into my shop with a level floor, I tried backing up and it was as smooth as always. Now that I'm thinking it through, both times that it chattered real bad was after the clutch was hot from light to light traffic in the heat. I've never really noticed much chatter from any of the Spec 3+'s that I've owned before...one was in another Cobra (700 WHP) and the other in my stock Z06. In fact, I've always bragged about how little they do act up when hot. I'm going to adjust the knob in 1 click and see what happens (I took it out 3). I'm really perplexed that I'm having any issues at all with the tranny. other than being notchy like most of them are, I haven't had a lick of issues with it other than being somewhat noisy....and I think that's a result of all the hard bushings in the driveline and suspension. That Full Tilt Boogey kit really makes everything nice and stiff, and really cuts deflection and wheel hop by a bunch; however, you hear a lot when going down the road. I hope that all of this is just clutch woes....that's a fairly inexpensive fix when compared to doing an entire tranny....especially if I go through it with all the high end stuff like the $600 output shaft. Thanks for the help.
     
  7. ZR5.0

    ZR5.0 Member Established Member

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    Did you ever get this sorted out? If the trans was pulled down I'd bet you find the same as I did in mine, snap ring that holds 6th gear syncro in place was broken in three pieces, trans jammed when backing up. Previous to it jamming, had a weird off and on chatter in reverse only, at times virtually smooth, other times not.
     

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