Carbon-kevlar synchro's, steel forks and sliders etc. I blew my stock tranny a month and a half ago.

After a run or two lately, I've gotten stuck in gear

My mechanic says that when my clutch was installed, the installer didn't do the drill out mod on the master cylinder. He mentioned something about in 3rd gear and higher that the hose for the tranny fluid is half the size as the lower gears (he said a lot . . . I might be recalling things differently) . . . he said that this was a restriction made on all F-bodies but not on the Cobra's or Viper's . . . does any of this ring a bell?

Bottom line, supposedly at WOT my tranny is heatin' up and no fluid for the tranny . . . would a custom tranny cooler solve my problem or is there something else goin' on here?
My tranny is fully warrantied including labor . . . but I don't want this happening every 2 months

Any input is appreciated. Thanks!

 

The M6 (T-56) transmission is "splash lubricated". There is not a fluid pump in the 6 speeds like there is in an automatic. If the trans is overheating, it is due to either a low fluid condition or an extended amount of running time at high speeds (140mph plus...). The drill mod is for the hydraulics that actuate the clutch and have to do with clutch operation (engagement and disengagement) but will not affect gears directly. If you are actually overheating the gearboxes, I'd look into Redline or Mobile 1 synthetic transmission fluid to reduce temps. If it is getting stuck in gear due to a mechanical failure (which is more likely), there is not much you can do except use a shifter with overtravel stops (B&M Ripper, Pro 5.0, Hurst Comp plus, Hurst Pro Billet, etc) or quit beating on the gearbox. These boxes will take a pounding, but extreme use will break things. D&D performance has some upgrades that may help keep it working for you such as upgraded shift forks and some other goodies to improve strength. I hope this helps....good luck!

 

Thanks for replying
My tranny was rebuilt with all of D&D's stuff in it a month ago. I don't power-shift or rev-match with clutchless shifts, never have. Either my drill-out mod is causing the engagement/disengagement problem or my shifter is screwed up . . . at times
I'm gonna do the drill-out (if, as I suspect, it wasn't performed already) mod, use the purple stuff in the tranny and gears, get a brand new slave cylinder, and custom fabricate a tranny cooler . . . if this doesn't work . . . say bye-bye Firehawk.

 

To do a tranny cooler, you will need a pump to pump fluid to the cooler. Tilton makes a good one...check www.truechoice.com among others. THe pumps run $199.00 and you'll need braided line and fittings to plumb it up. Good luck!

 

Do you guys think I need to replace the master or should it be fine? It's gonna cost me 160 . . . I do have 43K miles on it . . . it's not that much in order to be safe.
Did the master get over-stressed in any way due to the line restriction? If it didn't get over-stressed than I might not get it . . .

 

Dude, thanks for the info!

 

The restriction that they are speaking of is built there from the factory. I doubt it has damaged anything or is bad.

The cooler info....no sweat, I've been looking at doing that for road racing and such (and one for the rear axle as well).

 

I've been digging into this today. It seems the '01 & '02 cars in particular are having tranny problems. Popping out of 3rd & getting stuck in 4th seems to be the usual manifestation. Some have posted that the casing may be the problem. Do a search for more info.

 

I've heard that....and it may be correct. I can say that my 2002 has been perfect, but I autocross and am not a drag racer...though I have chirped the 3-4 shift on the freeway on occasion...I generally don't beat on mine...

 

All year f-bodies have this problem. The LS6 master with the drill out mod works wonders for pedal pressure. My friends had this problem on two 98's. If the shift fork is bent that could also make it hard to engage. I would just do the drill out mod, and maybe consider putting a piece of metal as a heat shield in between the master and exhaust to keep the clutch fluid cooler. Use the best clutch fluid you can get when doing the master (ie higher temperature range).

 

I have 2391 runs on mine and have NEVER had a tranny related problem,three clutches in 9 years that is all,try finding a 94 T-56 or learn how to drive within the limits of your hardware.

A guy up here has gone through 2 diffs,6 or 7 clutch combos[CF/STAR/McLeod] and 3 trannies on his 99 T/A.He doesn't even have 100 runs on the car in 4 years,he really doesn't know how to drive and doesn't take advice.

 

Sorry to bring this back form the dead, but I wanted to find out what exactly happened. I had my transmission stick in 4th gear, and sent it off to have it rebuilt. Steel synchro keys, carbon fibre blocking rings, steel shift fork, etc. The tranny worked so flawlessly and so smoothly I was in awe for two weeks. It then got stuck in 4th again. So we are facing the same dilemma. I haven't even really got a chance to beat on it yet, as my cam/headers aren't installed and I'm making similar to stock power levels. I'm stumped as to what it could be, but thankfully (Rodney), from transmission specialist said not to worry about it.. that he'd take care of me.. He built the transmission but we didn't really discuss much about warranty due to my intentions of abuse in the future. Hopefully that goes well. If you figure out exactly what it is, let me know. I have done the drill mod, and it still got stuck in gear. I'm using a ram 402/980 with mcleod adjustable master. Pro 5.0 shifter. Chirped the 3/4 shift 2-3 in the 2 weeks after the clutch broke in, but other than that haven't abused it. The tranny got stuck during normal usage when I was going to downshift to enter my neighborhood, it wouldn't come out of 4th. However, the first time it got stuck before I sent to have it built up was racing a motorcycle. So it looks like it could happen at any time. I'm puzzled.. Something apparently came apart, and Rodney at Transmission Specialists in Indiana said he would give me the info. Kudos to him and his business, as he gave me an excellent deal on the build up, and is now standing behind his product.

I do believe if it was a heat issue though, you would have been able to feel it in the transmission. If you were starving it for fluid, or overheating the fluid the transmission would be notchy as hell. Just a thought. Once again, if you ever found it what it was let me know. Thanks!

 

Never heard of a heat issue with our trannies.

IMO the drill-out mod and adjustable master with a good clutch will do ya fine. Of course most of the dependability is based on the machinic that does the work on the trannies.

I had mine completely gone through last year - D&D syncros and 3-4 shift fork - believe it or not I had it done at the dealership. Expensive but noone else will touch my tranny around here. Perfect ever since. I have the drill-out, McCleod cevlar clutch with its adjustable master. Launch at 5800 rpm's on 100 shot nitrous out of the hole off a 2-step. Still going strong.

David

 

those of us that have been through this, are telling you what the problem is. if it were something as simple as a heat soak problem, we'd all have coolers on all our setups. the deal is, that out of all the tranny problems that everyone on this board has encountered, yours is no diffrent. do you have an 01 or newer t/o bearing, or an adjustable master? have you added an A/M shifter? these simple things along w/ the addition of a correct clutch t/o distance cured my problems. and believe me it was nothing short of hell there for a while. at least you learn how to drop the tranny in about an hour ;D

just take the advice of somone who's been there. it's the little things.

 

Just to let ya'll know GM also sells a complete cooling kit for the t-56 (pump,hose,fittings ETC...) Designed for road racing.

 

I have a Mcleod adjustable master, 01/02 slave, pro 5.0 shifter, built up T-56.. ram 402/980 pp/clutch. Drill mod was done. I spared no expense on components. It got stuck in 4th, sent it in, rebuilt with steel shift forks, steel synchro keys, etc. 2 weeks later.. stuck in 4th. clutch is engaging/disengaging fine.. no grinding occured during driving of the car. Stuck in 4th under regular driving conditions the second time, and under semi-abusive driving the first time. No repetitive abuse or overheating of the tranny. I'm not really asking how to cure the problem as much as I was asking what actually broke to make it stick into 4th. During first rebuild, my tranny didn't have a bent shift fork. Now it has a steel shift fork, and 2 weeks later its stuck in 4th again. This is what most commonly say the problem is. I haven't mailed it off yet, nor will have time for a few days. My warranty mainly covers covers my tranny if its not my fault. I'd like to know a little more about what it could actually be wrong INTERNALLY with the transmission. That way I can go into the situation knowing what I'm talking about, and not get jerked around.

Everybody has said it could be overheating, it could be this that and yadda and so forth. But what is actually causing it not to shift out of fourth? It has to be something inside the transmission if it is doing it while its out of the car, or in neutral. It is completely jammed and won't come out no matter what. This happened to the guy who made this post, and I thought it would be beneficial to bring it back for technical information pertinent to my situation, and possibly others. However, apparently he has not had time to respond. I've replaced my transmission 3 times now, and the car only has 25k miles on it. Of this 25k miles, I've only owned it 7k. The car had has not had the pilot bearing replaced, but unless it was defective from the factory.. it shouldn't have caused the failure in such a short time to begin with.

And just a quick question for Vents.. If its not heat, what is it? What is causing this breakage, or whatever it is that is occuring to make it get stuck in 4th. Have you had thi exact problem? I've bought everything I could buy.

Oh.. and yes It is quite a nice practice. Time to install transmission is nearly instant!!

 

well, i didnt intend to sound like a jerk, but my personal experience is that the synchro keys falling out have repeatedly caused my transmission to get stuck in gear. also, do you trust the shop you took it to? my reason for asking is that, when you drive it, experience the problem, and then service the thing yourself, you learn by experience, which is invaluable. do you shift the tranny really hard? and i mean like slam the gears? the fork pads in these things are designed to be the weak points, but when they break, they take out all kinds of expensive parts. like synchro's, knocking the keys loose, and can even cause them to break blocker rings. also the selector mechanisim gets worn out much quicker when you shift them hard, easily overlooked by a "pro" tranny guy. luckily i cought this in mine the first time. problem solved. i've broken so many transmission parts, it's kind of a routine deal now ;D running one of these is kinda a process of breaking and rebuilding them. but you'll never learn what caused it unless you do it yourself.

the reason i dont feel that it is excess heat is that, this is a mechanical problem. and i have experienced it myself, and know i the solution. just because you had it rebuilt by a "professional" dosent make it right the first time. if it were heat, you would think more people would be experiencing it also as well as cooling kits being more widely used.

*edit* i'll put money one it being a worn selector mechanisim. w/ all 6 possible positions and the moovement, friction, and caused wear on one part, gives this piece a priority when doing a rebuild. it's a 20 dollar part from d&d *edit*

http://photos.yahoo.com/bc/vince0718...=ph&.view=

see pic#4

 

There is a shim that goes inside the input shaft before the main shaft goes on top when the trans is being put together. It is very easy to loose this shim during the cleaning a rebuild procedure.
If there is a lot of lateral play at the end of the input shaft that's the problem.

 

Also I have heard that the LS1 cars have tremec parts which are weaker in their trans while the LT1s have the straight up Borg warner which is why most of these posts with breakage are LS1 cars.

 

I can't believe no tranny shop or builder has caught this yet! I know EXACTLY what it is, as it took me 4 times of rebuilding my own to find out what was going on. I really think that Tremic needs to release a technical bulletin on this. Anyhow, here is the problem....

PROBLEM
If you use a shifter with no shifter stops, then you are relying on the guide plate inside the transmission to limit your throw into each gear. Normally, this would not be a problem. You can take each slider and put it in every gear as far as possible (until it rests against the gear), and the keys stay in, and everything is hunky dory. HOWEVER, if you take the slider and try to put it into 4th gear as far as possible, you will notice that the keys will try and pop out. When they pop out, they pop out twords 3rd gear, and actually get locked on the 3rd gear blocking ring, and cause it to semi "engage" 3rd at the same time. Once this happens, and you have two gears engaged at the same time, the weakest part goes, being the syncro keys in this case. They shred in half. When this happens, it makes it almost impossible to get it out of 4th gear, as the half sheared keys left act like a wall and catch on the slider.
NOW, the reason this doesn't happen to everyone, and usually takes a while to happen is simple. The ball on the guide for the gears actually stops on the tranny case for 2nd, 4th, and 6th. It is the case that stops you from going "too far" into 4th. What happens is simple, after many hard shifts into 4th, you begin to dent the aluminum case, which allows it to go into 4th "too far". Like I said before, you can't go "too far" into ANY gear and cause a problem EXCEPT for 4th. The reason 4th is this way is because of the design of the gear and the distance between the input shaft and output shaft.

SOLUTION
The solution is VERY simple, use a shifter with stops, and adjust them correctly!! I know, sounds simple, but often the hardest problems require the most simple solutions! After 4 rebuilds of getting 50 miles each rebuild before getting stuck in 4th, I discovered this, and adjusted my shifter stops correctly. Guess what?!? 10K miles now!!

I have rebuilt over 50 T56's here locally. I have run into two other T56's so far with this exact same problem. Each time using a shifter with stops has solved it.