02NBMWS6

iTrader: (22)

my trans is always popping out of 4th gear. it doesnt happen on the first couple shifts to 4th when the trans is cold, but as soon as it warms up: i shift to 4th, it goes in smoothly, and go to release the clutch, and as soon as the gear gets any load on it i hear a grinding and it pops right back out of gear. it doesnt happen on full throttle shifts, mainly on just normal cruising shifts.

which internal parts of my tranny are toast?

calhoon

iTrader: (6)

Classic problem / classic fix. Get an iron 3/4 shift fork.

ls1 joe

iTrader: (37)

Sounds like you have broken 3-4 slider keys. That is most likely what is causing the problem with the popping out of gear.

Thanks,
Amber

02NBMWS6

iTrader: (22)

thanks guys. I just spoke with Amber and i guess its time for the rebuild sooner than later.

PunkNPonys

iTrader: (2)

My third gear is doing the exact same thing yours is. I was told it was the 3rd gear sychro. Is this correct? I am going to rebuild it soon. Thanks

ls1 joe

iTrader: (37)

Most likely keys than the synchro. The synchro keeps it from shifting at higher rpms.

Thanks,
Amber

PunkNPonys

iTrader: (2)

Thanks for the info. I will look into replacing the keys. I also had another question, sometimes when i am at low speeds while in gear i hear the gears grinding or even sometimes feel it in the shifter. What can cause this? Thanks for the help in adavance.

pontiac

iTrader: (4)

the poping out of gear is the Slider assembly. but a bent 3-4 fork is most likely the reason the slider assembly being worn out. while you are in there, put the billet keys and steel fork so it will not do this again and get a new 3-4 slider assembly. I put a new 3rd gear too to make sure all the parts that where not rite got fixed, (mine poped out of thrid)

Vintage Iron55

Unless you have broken the fork, you have a bad gear. The usual reason for popping out of gear would be worn engagement teeth on the gear it's-self. Not the most comforting answer, but most likely the correct one. To correct this, do everything Pontiac said he did. All those components take a dump together. If you replace only the slider assembly, the problem will remain and most likely ruin the new slider assembly, as these parts will clash when you shift. They must all be sharp to deflect and pass between each other. The good news is I think the engagement teeth on the input shaft can be replaced separately from the input as they spline onto the input shaft.

fuseone

just pull the trans get it open and look and then you will know what it is for sure

calhoon

iTrader: (6)

Vintage
You really dont know T56s very well. The clutch teethon a T56 gear( all of them) are part of the gear so damaged cluthc teeth require a gear change. Jump out of 3rd&4th is a known problem with the aluminum shift fork wear. It does not need to break . It wears where in fits on the rail. The iron fork solves the wear problem and should be a part of any T56 rebuild.Broken struts( keys, dogs, whatever) will generally cause a trans to stick in gear. Although you could also have broken struts, they are not causing your jump out problem. Once a trans has been jumping out of gear awhile, the gear clutch teeth can be permanantly damaged( at the back taper) and the gear itself should be carefully examined for wear at rebuild.

pontiac

iTrader: (4)

The gear and the engaugement teeth are all one peace. thats why i bought a new 3rd gear, and a new slider so everything is new, and new syncros as well. the fork is whats causes the problem, but the week sheet metal pressed keys are what let you over shift the tranny, putting extra presure on the shift fork, causing the slack where the fork is on the shifter rail. the new rail doesnot get the slack in it, but the new billit keys will not alow you to over shift the tranny in the first place so the exta pressure never gets to the fork, but still put a new one it as well. between the two, the problem will be fixed from doing this again, to fix the current problem, the slider and gear. and syncors are allways a good idea

carado1984

ok how about this.. mine pops out of third at low rpms and if you shift into third it always grinds unless you hold the clutch in for a couple seconds.. say i shift at 5400 hold the clutch in and it drops to 3k then shift.. it doesnt grind.. but if i would shift at 2000 immediately just pushing the clutch in for normal shifting it grinds

i guess what im trying to say is.. rpms dont matter as much as long as i hold the clutch in long enough, which sucks to say the least.. i dont even know what its like to have a 6speed ive been shifting 2-4 for so long..

help?

pontiac

iTrader: (4)

that sounds like a Syncro problem, the best way to explane this, is they are like a brake, as you try to shift into a gear the slider pushes on the syncro and the syncro pushes on the gear, to either slow it down or speed it up to a close enough speed to let the slider lock onto the engagment teeth. if the syncro does not do this then you are waiting on the rpm's to drop to a place where it can go into gear. you can test this by rev matching the rpms and try sliding it into gear.

or, you have a whole nother issue, like the clutch no disengaging all the way. so you are pulling it out of gear and trying to put it into gear with the clutch still in contact with the flywheel. this is what make some LS1 cars all most impossable to power shift from the factory, some will, and some will not. thats what the spacers are for with some aftermarket clutches.

TEX02SS

iTrader: (2)

good info guys...i love this forum....my 5th gear was popping out a while back...it would only stay in when i gave it gas, as soon as i let off, it popped out. I couldnt even shift into 6th gear at all. The dealership told me what the gear was seized to the counter shaft and that they had to replace the whole thing as it was unrepairable. Luckily the car was under warrantee and so everything was covered and I got a brand new tranny. The service advisor said that almost never happens...

GR33N GoblinM6

iTrader: (14)

do it the easy and best way... ship the damn thing to www.t56rebuilds.com and have Joe fix it the right way with better parts.... its cheap, its fast, you wont regret it..

carado1984

easy to do when you dont drive it everyday.

pontiac

iTrader: (4)

http://www.thegearbox.org/page/page/3813499.htm

thats where I got my parts