I need to replace the flexplate on my sig truck with a C6 trans. When dropping the trans, do I remove the pan and put a block of wood between the jack and the trans or do I leave the pan on? And what kind of ATF should I put in it? I have never removed a trans before so go easy on me. I wouldn't tear down this trans if it needed repair but I'm only removing it, replacing the flex plate, and re installing it which I hope isn't very complex.. Is there anything specific I should know about replacing a flex plate? Does it have to be torqued to a certain spec or should I just crank it down without getting too aggressive with it?

Here are the steps I see necessary for removal

Remove driveshafts
Remove transfer case
Remove the 4 nuts from the flex plate holding it to the torque converter
Remove dipstick tube
Disconnect speedometer cable
Disconnect shift linkages
Remove starter
Place jack underneath trans and secure with chains/straps
Remove bellhousing bolts
Remove crossmember
Lower slowly and pull out from under truck

And vice versa for installation

And no, I can't take it to a professional shop. Cash flow is tight right now and I need my truck fixed

 

-Disconnect battery so you don't shock yourself. Trust me, you don't want to...
-I wouldn't remove the transfer case.
-I wouldn't drain the trans either...
-Disconnect cooler lines if equipped and plug the ports.
-Make sure the linkage for the transfer case is disconnected as well....
-I HIGHLY suggest a trans jack and a friend or two...
-Make sure your on flat, smooth ground. Preferably paved. Will make moving the trans much easier...
-I would just move the trans out of the way enough to get at the flex plate...
-Yes there is a torque spec for the bolts. I don't know what it is...
-Inspect the rear main seal while your in there for leaks. That's the best time to change it...
-Leave the pan on and use wood to get a level hold on the trans. Use plenty of straps.
-Take your time moving it. It is very heavy so be careful... This is where a friend helps... Pay them with pizza or soda... Or whatever people under 21 bribe their friends with to get them to help pull a trans...

I'm sure I am missing some thing's, but that's what I got for now...

 

Okay I did some more research and finally found the right charts. Stock spec for a flexplate on a 460 is 75-85 ft lbs

 

drop the transfer case before trying to drop the trans.
trying to remove them as one piece will be very difficult, the transfer case will make the trans want to fall off the jack because the weight will not be centered.
and you do not need to remove the oil pan, just use a bottle jack with a 2X6 on the bottom of the oil pan to support the engine.

and make sure you chock the wheels on the truck, both front and rear of at least one wheel. once the driveshafts are removed, there is nothing to stop it from rolling

 

Depending what kind of jack you use, you can leave the t-case in place and just strap the entire trans/t-case assembly to the jack to keep it from rolling off.

If you do want to remove it, it's only six bolts (I think, might be +/- a few) but you'll need a new gasket for where the two mate up together.

 

Go to hb and get a motorcycle jack. They are fairly cheap and will be/can be used for all kinds of stuff. Best and easiest way I have found to remove bug motors.