JakeBrakeIH

iTrader: (22)

well SBChvy and my friend we're tryin to put in my transmission while i was at work and they got it in but it seems as tho my new m12 has a longer input shaft than my nv3500(about 1/2"-5/8")and it was bottoming out on the crank...has anyone else heard of such a problem? I remember reading that some of the 99 had slightly different crankshafts and didnt know if my truck fit into that...just wanted to check to see what you guys have come across...

EDIT

is the bellhousing different between an f-body or a GTO?

hirdlej

iTrader: (31)

Yes the GTO and F bod bell's are different. The GTO has a much smaller starter

hirdlej

iTrader: (31)

Also you need a new pilot bearing in the crankshaft I'm sure. That's prolly what's hanging you up

hirdlej

iTrader: (31)

And just like the 6L, only the 99 4.8L had a longer crank if the truck was ordered with a 5 speed

JakeBrakeIH

iTrader: (22)

yes i remember that the actually bell housing is different but i was wondering if it was shorter? i mean it is noticeably longer(input shaft) than my nv3500...i installed a new pilot bearing as well

JakeBrakeIH

iTrader: (22)

well i think it is different...found this on thegearbox.org

http://www.thegearbox.org/catalog/it...17/3697124.htm

gonna call em 1st thing in the morning

SBChvy

iTrader: (5)

Yeah it is definately a different input shaft Pete...about half an inch longer on the splines and shaft itself. Took some pics to show you better. We had the trans in and were drawing it through the pins when it just stopped. Initially I thought it was getting hung up on the dowl pins...after pulling the trans back out I peeked up to just make sure I wasn't catching on the new pilot bearing. Luckily it wasn't; however, I did notice the bottom of the hole was shiny clean-unlike it was before...seems as though we are bottoming out:

First pics are the nv 3500:

You can see the end of the input shaft sticks out about .25" from the bellhousing





Here you can see its about 2.00" to the end of the splines and 3.125" to the end of the shaft (measured from the throw out)





Now on the GTO T56 the input shaft sticks out about .875" from the bellhousing





And the splines are a little less than 2.5" away from the throw out and the whole shaft is about 3.625" away

Rafedial

iTrader: (7)

Pete,

I did not have this problem. The truck used to be a charged 5.3L/auto, then 6.0L/auto, now 6.0L/T56. The 6.0L was out of a 03 Cadi. Sounds like your crank snout is longer. Part # for pilot bushing?

Find a suitable starter for it yet? So, wait if the crank snout was longer, the flywheel sits back further? I'm thinkin....

EDIT: bellhousing on F-body T56 IS! different than M12 GTO trans. Smaller starter hole, NEED GTO starter.


Cody

JakeBrakeIH

iTrader: (22)

yeah i found a re-man starter for little over $100...but after looking at thegearbox.org site and seeing that the front input shaft is different for the vettes and GTOs so Im gonna call em and see what they suggest...I dont think that my crank is longer but anything is possible...

SBChvy

iTrader: (5)

Turns out '99 and early '00 Trucks do have the longer crank...which in turn pushes the flywheel back. Pete's GTO T56 is made for vehicles with the shorter crank-stock for late '00 and up trucks. I'm taking the input shaft out and dropping it of to the machinist tommorrow morning. I talked to Jeff@Tremec he said they have done this to handfull of input shafts...mostly on Cobra Kit cars...with no problems or failures. Let you all know how it turns out