The clutch master could be bad, or a leak in the system. Some clutch systems are a bitch to bleed, I'm not familiar with GTO, but sometimes they require a vacuum bleed kit.

As for the trans it's unlikely but possible, that the trans is shimmed to tight. But in theory if it is to tight the synchros may not spin on the gears and therefore "stick" cause rough shifts.

Does it shift better ounce warm? Then the case expands, and allows the synchros to spin "slip" again.

If there is two many shims and the trans is really loose, the synchro will spin to much, and not have enough force to spin the gear up to speed causing them to clash or grind. This will get worse ounce the trans heats up.

Also not to be an Asshat, but did you use ATF 3 or 4? You didn't use gear oil or synchromesh fluid did you?

No problem on the help, I hope you can get this straightened out.

The best way that I know off to separate clutch and tranny issues is to jack the rear up and start it put it in first release clutch then depress. see how long it takes to stop. if you didn't use the gas pedal, and it's just in-first it should stop within about 5-10 seconds. If it doesn't definitely seems clutch related.

You can also do the 1st to reverse test. drive forward on the ground in 1st come to a complete stop and go for reverse if it grinds the clutch isn't releasing, or there is a internal transmission problem!

 

Hi guys, I noticed that the manual does not have part numbers. Check out this document I got from my local chevy dealer. He said the pic is specific to a 2000 z28 t56.

links:
http://i1269.photobucket.com/albums/...nford/t561.jpg
http://i1269.photobucket.com/albums/...nford/t562.jpg
http://i1269.photobucket.com/albums/...nford/t563.jpg
http://i1269.photobucket.com/albums/...nford/t564.jpg
http://i1269.photobucket.com/albums/...nford/t565.jpg
http://i1269.photobucket.com/albums/...nford/t566.jpg
http://i1269.photobucket.com/albums/...nford/t567.jpg
http://i1269.photobucket.com/albums/...nford/t568.jpg
http://i1269.photobucket.com/albums/...nford/t569.jpg
http://i1269.photobucket.com/albums/...ford/t5610.jpg
http://i1269.photobucket.com/albums/...tanford/me.jpg


[edit: removed ridiculously large images]

 

Heres another link to the manual just in case

T56 Service Manual

 

Cam:
good point, I did not see that manual (damn, that thing is detailed. I've got some reading to do )

Although... I didn't see part numbers in either link so I will leave links only in case someone needs them and is too lazy to do a web search.



BTW- this is a great thread and I might not have done the rebuild myself without it! thanks LS1tech!!!

 

http://www.thegearbox.org/catalog/it...74/4455302.htm

I plan to rebuild my tranny next week and this manual may help... No idea how good it is yet but I'll post afterwards. I'll definitely refer to this write up as well, great job

 

I know this threads been dead for some months now, but wanted to extend a huge thanks to the OP and also to the shower curtain rod guy. Great write up and great idea! Huge help

 

I had to remove the front adapter plate to make some measurements on with the quicktime scatter shield i have. it came off with little to no problem.

is there any special procedure for reattaching the adapter plate to the rest of the transmission? I tried putting it back on but after i tightened it back down the shifter didnt feel like it was engaging in all the gears.

any advice or ideas?

 

Broke open my t56 with 156,000 miles on it. Heard the horror stories about the 5/6 cluster. Crossed my fingers and said prayers but sure as **** that thing was ON there! Tried twice with heat and pullers. I applied an unimaginable amount of force, but it held it's ground. so, I connected two 6" two jaw pullers and cranked it down with the impact. I left it over night and all day at work. Come home, go straight over to it and hit it with the acetelyne torch and POW! A few more turns with the impact and a lil more heat and it came right off!

 

You could have dropped the 5-6 and R shift rails out of place. To fix:
remove the reverse light switch
Lift the 5-6 shift rail so it's claws hook over the shift interlock ring properly and the groove at the top of the claws lines up with the guide bolt that's threaded into the case.
Stick a long thin screwdriver in the reverse light opening. That will hold things up.
Then reinstall the front plate.

 

Does anyone have the part number on the small taper bearing on the stubby end of the main shaft? Could not figure out how to remove the gears without destroying it and now I need a new one. All of the other bearings are perfect.

 

I have a complete bearing set that came with my rebuild parts. I'm not replacing the bearings and need to sell the new ones. Make me a decent offer and I'll send it to you.

 

https://ls1tech.com/forums/14259776-post16.html
there is the set # as well as the individual numbers.

 

This trans build has been a nightmare. I have an MN12 and it seems as though there are a lot of different parts. Is there a PDF for an MN12?

 

It's an interesting learning curve the first time through. Next one goes easier.

 

This is true. However I have a few left over pieces. An aluminum ring, a flat graphite washer and a rubber o Ring. The retainer is now in its correct place.



One part of concern is #108 thrust washer in this picture. I know for a fact that I did not misplace a single part and the only washer I have right there is a very thin washer (one on each side of the bearing) but its not thick like this. Any ideas? Maybe it's different on the mn12? It would be metal to metal contact but there are oil grooves on each part of the shaft.

 

108 is a countersunk washer on the double/single cone boxes.
It isn't present on the triple/double cone boxes. They instead have a thin bearing washer on each side of the 6th countershaft gear bearing and the gear has an extended tube section IIRC.

Flat washer goes on the hub of the reverse synchro under the wave spring, which is under the brass blocker ring.

There's a 40mm? rubber o-ring on top of the tapered bearing right behind 1st gear.

The ring looks like a bearing spacer; it should be obvious during assembly that a gear has roller bearing underneath it with extra room for a spacer.

 

The rubber O ring on top of the tapered bearing is a very thin o ring. Much thinner than this one. And that aluminum spacer didn't seem to fit anywhere that I could see.

 

A picture is worth a thousand words. Measurements are priceless.

GTO box, yes?

 

Yes GTO box. It's an alumining ring with no taper. And the rubber gasket also seems too big to fit on any part of the shaft.

 

These are the only two piece left that don't seem to go anywhere.

Aluminum ring


Rubber gasket