So ever since i've bought my T56 (i got screwed obviously) theres been an immense vibration in the 6th gear in the uper RPM 25k and up give or take, so i've pretty much ruled out using that gear

here's my assumption
i have a bad 6th gear shaft and i'll probably need to change the main shaft as well due to collateral damage

So i've been wondering how hard it is to actually rebuild a tranny yourself. what do i need to look out for?
and how much would i expect to pay a good shop to rebuild it for me?

any insight would be great

Here ya go

http://ls1tech.com/forums/manual-transm ... te-up.html

Not hard really. Done both an Fbody and Vette 6speeds in the past. There's a place in Detroit that has kits for them with CF blocker rings and so forth.

On the FBody one the gears slipped of the shaft pretty easy. On the Vette one I had to extend a gear puller with steel strap and use an impact gun to get the 6th gear off the shaft. Putting it back on was easy as I heated it in the toaster oven and then just drove it on with a piece of ABS pipe.

Good place for parts

http://www.thegearbox.org/T56.html

Its not that overly hard its just a matter of having all the right pullers and possibly making your own to work right. I helped do mine with Dean (warp10) and it took us half a day to pull it apart and inspect it to see what it needed. I think i ended up using sixspeedsinc for parts when they were still around. Brutal experience with them and will never do it again and they are now out of business, i wonder why Took us about another half a day cleaning everything up ready to install and put it back together. I bought mine used and wanted to inspect it before i put it in the car and it checked out pretty damn good it looked to have been rebuilt at some time (300,000+ when i got it). Reverse wasnt so nice but luckily its reversable and got away without having to replace it. I did the usual bronze fork pads, steel 3-4 shift fork, and two seals to complete it.

Here's some pics:

I had mine shipped down to Texas. $1800 with shipping both ways, the rebuild, and extra parts that needed to be replaced. A lot cheaper than getting it done here by someone who has never seen an LT1 T56. That $1800 includes taxes at the border.

Yep, that's the place we got parts from. They used to do full rebuilds but I think when we had problems getting the Vette 6th gear off they said they only do parts now.