Gen414

iTrader: (38)

Well guys, I got into a tranny for a member here on teh board yesterday. Tells me it got stuck in 3rd gear, got it out, then would not go back into 3rd or 4th. Mind you, this is behind a COMPLETELY stock motor LS1, still stock exhaust even!
I know this is no new revelation (broke shift fork) to most of you guys @ here, I just wanted to show some of the guys that may not be that familiar with our setups and what are the weak links and such. Well, here is one of them:

stock aluminum 3/4 shift fork:

camar0corey

iTrader: (22)

I've never seen the inside of a transmission, I always assumed a shift fork was a tiny part.

85MikeTPI

iTrader: (9)

Very nice pic.. I once argued with a fellow on another forum that the steel 3-4 fork was a waste, since "he" has never seen a stock one fail... LOL...

A picture speaks a thousand words...

I'd still go over that thing with a fine-toothed comb to verify everything is working properly.. To see that much damage to the fork would have to be binding under alot of force...

Gen414

iTrader: (38)

Ohhhh, I got LOTS more pics of the "inners" with nice carnage too boot...


Oh yeah Mike, you can tell that OP that the fork is right up there with the weakest part of the tranny (which I know YOU know). This is not the 1st broke fork I have come across, but IS the first broke fork behind a stock motor though.

Also, I just popped the midplate off real quick to see what was up with 3/4 before I actually get into it (he is going with our Level 2 rebuild).

I actually found a shift fork pad in the bottom of tranny as well (well, part of one) but the 3/4 pads are still there, so probaly 1/2 pads....

Gen414

iTrader: (38)

NOW, you can see why the "steel" 3/4 fork upgrade is so popular.

Torkman15

iTrader: (2)

Ive had an aluminum 3-4 fork in all my T-56s and never had a problem. I guess if I get it stuck in gear and pry hard enough on the shifter I could have a broken shift fork fork also. Sometimes fixing the root of the problem is a better way to fly.

NemeSS

iTrader: (127)

looks bad, i guess mine held up to more than that.
what could have caused this damage, missed hi rpm shift??

billymz28

My stock 3-4 shift fork didnt brake. I just broke the shifting rod in mine. But upgraded to a steel one in the rebuild

BES Stroked Nova

iTrader: (24)

I have a built trans... but sometimes mine gets stuck in 4th. I just shove it back out. and never really seems to cause a problem...

Gen414

iTrader: (38)

yeah, that is one way to break teh fork. Banging gears is also another way. Fact of the matter is, glad you have not broken yours, but IS a weak link in teh tranny...too many broken one's out there to say otherwise (and not from just being stuck in gear)

yeah, a missed shift could break it, sure. Basically, anything that could have put it in a bind, BEFORE the shifter rail stopped moving, could have broke the fork.

If you broke the steel rail, but not teh aluminum fork, is a weird one...

thesource

iTrader: (60)

Its not as common to break the 3-4 fork in the T56 like that but its super common to break the aluminum 3-4 shift for in the TR3650 found in the 01-up Mustang. At least Tremec offered an upgraded fork for the T56. Its a no brainer to upgrade the fork while its a part.

thesource

iTrader: (60)

I have never ever seen the shift rod break. I have seen the selector section that rides on the torxs bolt break. I have seen the steel section that hooks to the fork break and I have seen several stock aluminum forks break like the one in the picture.

97Z28SS

iTrader: (5)

Do they make a steel 1-2 shift fork as well, what other parts are recommended for a stage 2 upgrade/rebuild?

Gen414

iTrader: (38)

Not that I am aware of, no. However, since I have yet to hear of one breaking, then really no need for it.

The most popular upgrades are (like what is in our setup)

Steel 3/4 fork
Billet 3/4 keys
bronze pads on 1/2 and 3/4
Carbon fiber blocking rings...those are teh upgrades, and we also include:

New 1/2 and 3/4 synchros, seals and stock pads on 5-6-R (we do offer bronze pads on those forks as options)

97Z28SS

iTrader: (5)

How much for the stage 2 rebuild kit with bronze 5-6 shift pads, new 5-6 syncro and do the 1-2 and 5-6 shift forks need to be replaced as well? I have an LT1 T56 with 166k and it just started popping out of 3rd gear and does this mean I need to replace 3rd gear as well?

99LS6SS

iTrader: (4)

It's probably just your 3rd and 4th syncro assembly. Only way to tell if the gear needs to be replace is if the teeth that line up with the syncro are all chewed up and rounded off. So you probably only need the 3/4 syncro assembly which comes in their kit.

Gen414

iTrader: (38)

OK, PM coming as well...

No, 1/2 and 5/6 forks do not need to be replaced.

If popping out of 3rd gear, it could be synchro or engagement teeth on 3rd gear itself, or 3/4 shift keys (but would probaly do it in 4th gear as well if so), could be a damaged fork pad, or shift fork itself (but again, would probaly do it in 4th as well.)

That being said, all of teh above (except for 3rd gear itself) are replaced during a Level 2 rebuild.

Also, what year LT tranny?