Hello, I just bought a used t56 for my 87 Iroc and got a few questions. What piece is needed to get my speedo to work It is a mechanical speedo not the digital one. Also does the ECM need to see the speed of the vehicle to make adjustments to the fuel and timing, I don't beleive my vehicle had a speed sensor on the 700R4. How Does the ECm see the signal? thru the cluster? How about the slave cylinder I don't see a bleeder screw on it? what do I do to make sure there is no air in the system? Thanks, it's a work in progress.

 

"JTR (Jag's That Run) has a conversion kit available to change the electrical T56 output to a mechanical cable, but unfortunately, it is around $300. Abbot makes a black box that drives a cable speedometer as well, for a few hundred. Auto Meter has an electronically driven speedometer that accept's the VSS signal. I'm using this, along with a few others very succesfully."

You can also buy something so the transmission will have a gear inside to hook up a speedo cable, but I forgot where I saw that.

Here are all of my T-56 swap articles

4L60E to T56 conversion instructions for 1994-1997 LT-1

F-Body Motorsports 82-02 Camaro Parts, Z28 Parts, Camaro SS Parts, Firebird Parts, Trans AM Parts, GTA Parts, Iroc Parts, Formula Parts and Firehawk Parts - thirdgen5spdconversion

T56 6 Speed Conversion for 82-92 F-bodies


Universal Speedometer Signal Interface

 

Thanks for the info. Bleeding the hydraulic slave cylinder seems like a real PITA. Do you know an easier way? Could it just be filled and it will gravity bleed itself? I don't need the SGI 5 box for the mechanical speedo? I'm hoping only the Cable X box which PACE performance sells.

 

I'm pretty sure you don't need the SGI-5 box for the mechanical speedo, just a converter.

or

Here's the link to a rear tailhousing that will allow you to run a mechanical speedo.
https://shell7.tdl.com/~jags/T56_Order.html

The ECM knows the speed through the VVS(Vehcile Speed sensor). The T-56 may use the same one as in the 700R4, I'm not really sure.

www.ls1tech.com should have more information.

 

thanks for all your help transam12sec.

 

i did the conversion this last spring and i had a hydraulic line that didn't have a bleeder screw also.

what i did was in place of the bleeder screw was:
1)took the slave cylinder at the bottom of the hydraulic line off and pushed the cylinder in so it's compressed.
2)then put the slave cylinder on without putting the little pin back in i let the slave cylinder out which pulled fluid through the line.
3)while doing this make sure fluid is kept up in the hydraulic reservoir up top.
4)then i would take the slave cylinder back off adn push the cylinder back in.
5)i repeatedly did this until only fluid was coming out at the bottom not air.

just make sure you keep putting fluid in.

everyone i talked to had a hydraulic line with a bleeder valve on it but mine didn't so unfortunetly this is the only way i could get it to work.

i couldn't get gravity to work at my house it just didn't pull the fluid through the line.

 

Quick question about the clutch pedal lining up with the clutch master cylinder rod. I noticed that when I mounted my slave and pedals the rod does'nt line up perfectly to the mounting point on the clutch pedal, it is off slightly. Is this going to be a problem or will the hydraulics make up for the proper travel of the clutch fork? I made my holes using the existing template cut out in the carpet. At the time seemed to be pretty accurate. Thanks guys.

 

This pic was taken off the guys whos doing a LS1/T56 swap.



I don't have an answer right now, I'll reply if I find something out.

 

mine was off a little bit too, but by making up for it I drilled the mounting holes a little bigger and used washers to hold the master clylinder mount in place. this was a little bit of a pain in the butt to line up but i eventually got it.