GMT400 4L60e to T56 swap write up *dialup warning*

[90'rado]

Thanks. Yeah, used a buddy's lathe. Thankfully I have some machine shop experience from the past so it wasn't too hard.

 

[Aloicious]

great work! that would be the way to go for a pre-OBD2 truck.

 

[KennyB01]

we'll i'm back, took a little longer than i wanted but i figured i'd do the swap over the laborday weekend. i will say it is harder getting the 4L60 out than putting the T56 in. Aloicious i am having trouble getting the master and slave cyl. to bleed out. is their a trick our is it just hard. thanks

 

[Aloicious]

what slave are you using? I found it easiest to bleed the T56 slave (the one without the bleeder screw), to have the lid off the master cylinder, fill it about 3/4 full with fluid, get under the truck, and with the slave NOT attached, tip it so the pushrod is facing down, and with your hands, manually push the pushrod in all the way, and hold it there for a couple seconds, and let it come back out. do that again, then get back up and refill the master to about 3/4 or so, to that sequence several times. then when you think it may be bled well, get someone to simply watch the master cylinder fluid while you push in the slave pushrod, if they see any air bubbles escaping, then you need to continue the sequence more until there is no air bubbles in the system.

it took me a few trys the first time to bleed it correctly. once you get the hang of it, its pretty easy. even with my '92 camaro 305 5 speed slave (which works just fine on the T56 and is made of aluminum instead of plastic) that has a bleeder screw on the slave, I still do most of the bleeding like mentioned above as I find its a bit more efficient, then after I do that, I use the bleeder screw just like you would bleed the brakes, as a simple double check to watch for small air bubbles.

hope that makes sense, let me know if you get it bled.

 

[KennyB01]

i did get the 305 T5 one but i also got the last of the aluminum ones, the are giving out the T56 ones now for the T5. i guess they found out that they both will work and save money and inventory buy just making one, or they have been reading your Thread. but when sun comes up i will give it a shot. thanks

 

[KennyB01]

we'll that was the ticket. thanks Aloicious. will do a write up on the performance after i get a shower and take it out for a run. i did notice the abs light is on now but i have not had the ecm reprogramed.

 

[KennyB01]

just got back from playing around with the manual, i have not did no wiring yet and i unscrewed the reverse lock out so that i would not have no issues with reverse, that will be the first thing i fix. if you deside to go the route Aloicious went with the ’03-’04 Cobra T56 Pro 5.0 shifter do what he did and enlongat the two holes he did, i took another avenue and had a guy in our tooling enlongat the holes to where they were centered (routered out all four holes to center it instead of just doing the two) and the shifter try's to jump out of gear in all the uper gears (1st, 3rd, 5th and reverse). so i will be getting another one to do like he did. the only other thing i have to do is get the computer programed and finish the wiring. i left the nuetral saft swith in taked for next weekend. the two things that is a must is the clutch safty (every time i jump in the truck i go to crank it before i press the clutch in) and the reverse lock out (i have hit reverse gears twice now, just enough to tell me i do not need to go their). and the torque management that GM imposed on our truck is playing hell on take offs. but that will me cured when i have the computer do (sure would like Aloicious 411 and 24X that would solve my problems).

 

[Aloicious]

if you don't want to wire up the reverse lockout, don't take the solenoid out, just don't wire it up. if you leave it in, it will still prevent you from going into reverse, you'll just have to muscle it a little bit when you DO want to get into R. you'll have a good amount of problems if you don't get your PCM tuned, not just an SES light, the takeoff problem you're getting isn't torque management, its probably the PCM trying to prevent you from driving since it thinks you don't have a transmission. there are alot of PCM tables linking the trans and engine calibrations.

 

[KennyB01]

ya, i sent one to nelson performance but it will not be back untill next week, the reason i did not want to force the trans in to reverse is because i had the shifter relocator installed and the way it looked i was worried that that section that was cut and spliced back togeater with that special casting would be a week point. but after work tomorrow i will go ahead and put it back togeather and hoo it up. thanks

 

[Aloicious]

ah gotcha, I'd get a better shifter/setup for that, it sounds kinda iffy, mine has been rock solid. if anyone is going to alter a shifter for the relocator kit, I'd for sure use a cobra shifter so that you only have to alter the 2 holes, and the other 2 are right where the should be.

another reason you might be popping out of gear is if you elongated all 4 holes, the shaft on the shifter might not be mating with the shift rail adapter in the trans. with my cobra pro 5.0 I could line up one side of the shifter mounting holes, and it would mate with the trans perfectly and straight down, but if I ligned up the opposite set of holes, the shifter would not mate correctly (it would be angled). and since you altered all 4, it might be slightly out of alignment enough push it out of the upper position gears. that would be my theory at least.