Rob WS6

iTrader: (16)

I just finished the T56 swap in my 98 Trans Am... I did tons of searching, reading, cutting and pasting so that I would have the knowledge to do it right without any guessing.

I wanted to post up some observations I made that I think may help others looking to do this! Most of this info isn't new, but its nice to have some of it all in one place.

-Reverse light connector PN 12126452. Get it from ebay for like $7. Don't have a PN for the reverse lockout connector yet, though it was the same connector as used on a 3rd gen TPI smog pump, so I just cut it off my 92 lol.

-Torque #s:
Flywheel bolts = 74 lb ft in 3 stages, 15-37-74.
Pressure plate bolts = 52 lb ft
Slave Cylinder bolts = 71 in lb

-LT1 and LS1 clutch pedal assemblies are the same aside from the return spring that is on the LS1s. If you go with a Tick master like I ended up with, youll want to remove that spring anyway.

-The torque arm bracket and y pipe hanger that attaches to the T56 is different than the 4L60E version, and is NOT interchangeable. Make sure to get the correct brackets with your T56 or order them before hand.

-The VSS wires needs to be extended approx. 6". The connector remains the same and is reused.

-When you remove the automatic shifter, you lose the center mounting point of your console. You can either order the correct bracket that also holds the air bag module on, or you can cut the back 1" or so portion of the shifter plate off, and continue using that. I cut the piece off of my old shifter plate and it worked great!

-Don't guess when cutting the shifter hole. Turn over the 6 speed lower shift boot that you got with your swap, and make a cardboard template from the inner lip. With the shifter gone and bracketry cut out of the way, youll see that you can only place the shift boot in one way. Youll see what I mean. Mark its position and the mounting holes, then using the template you made, mark that and cut. I used holesaws for perfect corners and a cut off wheel for the straights, and it looks factory. Don't forget to mark and drill for the 7 fasteners. I went with 1/4" holes and then fastened the lower boot with oem style speed clips installed on the tunnel and the oem 7mm screws. The metal is thin, if you just put the screws right into it they'll probably strip out after one or two removals.

***DONT FORGET TO FILE AND PAINT THE CUT EDGES OF METAL, WE DONT WANT TO CUT OUR HANDS AND HAVE THE METAL RUST OUT!***

-The firewall is thin and flexible, you WILL NEED a reinforcement plate. I found a picture of an oem plate someone had removed from a car and made mine off of that, Ill try to post up some pictures and dimensions.

-Cutting the master cylinder hole wasn't too bad either. Instead of using a large 1-3/4" hole saw most suggest, I decided to go for a more factory looking using a 1-1/2" hole saw and make the opening oval on a vertical axis, like an "0" not an "O". Less material removal=stronger firewall. Alignment was fairly straight forward, just cut out the pre-punched piece of plastic under your carpet, mount your pedal assembly temporarily in position, mark where the holes end up, and using a template, mark where the oval center hole will go. Center of the master hole should be around 4-1/4" from center of steering shaft. Again, file and paint the metal edges so there's no rust.

Ill add more to this as I think of it... For some reason my reverse lockout wiring isn't working yet. Im trying to get it to work like factory off of the PCM. I haven't had a chance to troubleshoot it yet, Ill post up more when I get it squared away.

Badazz 97 TA

iTrader: (18)

good tips. i just finished my swap as well this weekend. You hit every little problem right on the head. That's a lot of the stuff I ran into also. Definitely post up the dimensions of the plate when you get it. I still have to make one for mine.


Did you have to connect the 12gauge brown and yellow wires on the shift pack connecter together to start the car? Do you know what those wires actually do?

Rob WS6

iTrader: (16)

Yeah, they get extended and connected to the clutch switch, the black one that gets depressed when you push the clutch pedal in. That way the car will only start when the clutch pedal is pressed. If you don't have the connector pigtail for the black clutch pedal switch, blade connectors fit perfectly as a temp fix. Always try to solder wires to crimp terminals for reliability, never crimp!

Badazz 97 TA

iTrader: (18)

ok got it. Yeah I have the pigtail. Do you just leave the 2 remaining cut ends alone once you extend it for the clutch switch? Obviously your going to have 2 unused wires once you cut it. Right?

Rob WS6

iTrader: (16)

Well the green and brown wires go to the reverse light switch on the pass side of the transmission. Orange and black wires go together for the hatch release. The other two go to the clutch pedal which we already discussed... that should pretty much cover the basics of the wiring. Depending on what year car you have, youll need to wire in the cruise control switch that's on the top of the clutch pedal. From what I understand, on a 98 car, you can just wire in in series with the one on the brake pedal, on 99 up cars, the PCM looks for that switch so youll need to run a wire to the PCM for your cruise to work.

Badazz 97 TA

iTrader: (18)

ok that makes sense. I have a 97 LT1. I didn't have to do anything to my hatch wiring, it works normal, unless that wiring is to prevent it from opening while driving? Havant tried it yet. I'm gonna knock it out once I get back in a week. Definitely still post about that plate dimensions when you do it.


Do you have any idea if a auto pcm reflashed to a m6 will work with a m6 engine harness?

redbird555

iTrader: (14)

nice tips man. also not if you use a tick mc the stud on the firewall by the m/c will have to be taken out. also the reason the reverse lockout may not work is that the op has not flashed in an m6 tune. without this the pcm will not send the ground signal to the trans.

for everyone's questions including the op's about reverse lockout and cruise control refer to my write up. the cruise control portion is towards the bottom. on the 97 lt1 it should be just like the 98 mentioned in the thread. if the op's car is a 99-up cruise control will not work once he flashes in the m6 tune without wiring a pcm signal from the pedal.


https://ls1tech.com/forums/manual-tr...e-writeup.html

Rob WS6

iTrader: (16)

I already flashed an M6 tune, which is why Im curious as to why it doesn't work. I am a 98 BTW.

I used a Tick MC and didn't have to remove the stud, doesn't interfere with anything that I can see.

redbird555

iTrader: (14)

if you are a 98 then it simply just needs to be extended to the clutch pedal for cruise. what pin do you have it wired to in the pcm? do you have it like i do in my writeup?

also the stud will not interfere with it being mounted but due to the head on the stud on the outside of the firewall the large billet bracket on the m/c will not sit flush as its supposed to on the firewall.

Rob WS6

iTrader: (16)

For the reverse lockout, its pin 42 Red at the pcm which will connect ground when the pcm wants reverse lockout off. I have a diode wired in as well. I have to make sure Im actually getting 12v, I pulled it off of the pink wire from the rear o2's which I don't use.

Ill have to check out if that stud is interfering, the master seems to be sitting flush and my holes might be slightly different so that it doesn't interfere. Ill report back on that.

redbird555

iTrader: (14)

hmm where and why do you have a diode wired in? i'm not sure what voltage the o2 sensors operate on however. I have mine wired into charging port on the console. i would think o2 sensor voltage would fluctuate as the sensor works and the heater signal would turn off after the sensor is warmed up so perhaps try switching it to something else?

Rob WS6

iTrader: (16)

https://ls1tech.com/forums/4808088-post239.html

This post. And thinking back, theres a good chance I may have wired in the diode backwards, effectively eliminating the solenoid as now the diode is acting as the solenoid. Oops! Ill fix it and report back.

redefined

Good post, bookmarked for future reference.

Rob WS6

iTrader: (16)

Of course it snowed 8" here last night, and have been sick for the past week. Ugh... all the hard work and Ive only been able to put less that 40 miles on the swap. I wanna drive the damn thing!

Spartan7

iTrader: (7)

That's the wrong way to wire your hatch release. With it wired that way, if you accidentally hit the hatch release while driving, it will pop open. The right way to wire it, which is how GM wires the M6 cars, is to splice the orange wire to the e-brake signal wire, so the hatch release only works when the e-brake is pulled.

Rob WS6

iTrader: (16)

You're right about that, I know it will work when ever. Didn't think to wire it into the ebrake, that's a simple fix. If the snow ever melts off my car, Ill get to it!

oldmano2z

on my swap I disabled cags,reverse lockout, and clutch pedal. plugged the solenoid holes with caps, pulled reverse syncros so it only goes in reverse at a dead stop. clutch wires I spliced together you push the clutch in before you start anyway. I have a 1SC so no cruise control,hatch button. handy to start, don't have to be in vehicle to start car just make sure out of gear and emergency break on . you'll learn to use the break more with a 6spd. i'm old school didn't have clutch switch old days . just have to be aware of surroundings. I think you need clutch switch for drag strip though. I also use a monster#2 tick master,speed bleed ,and mgw. tranny guts that's another story in it's self. by the way gm syncromesh transfluid and don't look back... the oldman...

Badazz 97 TA

iTrader: (18)

Did you ever get a chance to make that plate for the firewall and pedals?

Rob WS6

iTrader: (16)

Ill try to find the template I used tonight...

*edit* As I suspected, I had wired the diode backwards in the reverse lockout circuit. Switched it around and it works perfectly now, just as it should from the factory.

I also spliced the orange wire into the light blue wire going to the ebrake so the hatch release only works when the ebrake is pulled up. Works great too!

Badazz 97 TA

iTrader: (18)

OK thanks. Whenever you get a chance, no rush.