Transmissions and DrivetrainNeed help with your trans? Problems with your axle?
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first off.. im new here. Im not new to mechanics but new to new mechanics such as electrical and what not.
I have a 89 5.7 tpi auto that im going to be doing a t56 swap too. A few questions to see if any of you can assist me in the right direction. Im really not understanding the VSS situtation, can someone explain this to me? i have read the skulte write up and it confuses me. What do i need and where to get the parts would help alot. Also About my ecu... do i need to change this? run a chip? im totally lost on this section aswell. Any input would be greatly apprieciated. Thanks.
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I'm not sure if your car has an electronic speedo or not. If it does then you need a Dakota Digital SGI 5 (about $150) to convert the 4th gen VSS signal to a 3rd gen signal to get the speedo to read right. However, even if you don't have an electronic speedo you still have a VSS. On mechanical speedos the VSS is built into the speedometer. The VSS sends a signal to the cruise control module and the ECM, so if you want your factory cruise to work and to have proper ECM function you need a Dakota Digital SGI 5 to convert the 4th gen VSS signal to one a 3rd gen cruise module and ECM will understand. If you don't have cruise, or don't care if it works you can have the table in the PROM reprogrammed to directly interpret a 4th gen VSS.
If you have a mechanical speed I'd suggest using an electronic one like one from Autometer (that's what I did). You could also use a stock 3rd gen electronic one and use the Dakota Digital SGI 5 as noted above. Or you can buy a conversion box from Abbot or a modified tailshaft housing from JTR (Jaguars That Run - don't let the name confuse you). This will allow you to keep your mechanical speedo and run it off the T56, and will also allow you to keep the stock VSS and there's nothing to wire. The downside is cost; about $350 last I checked.
As for the PROM (chip) you may need to have one burned to compensate for the change, and you may not. I've read posts from several people that kept getting trans related SES light, and needed a new chip to solve the problem. Others have not chnaged the chip and experienced no issues.
If I were you, I would ditch SGI5 or any other similar junk. since you have cable speedo, I would recommend to do conversion to the tail housing to accept mechanical speedo.
If I were you, I would ditch SGI5 or any other similar junk. since you have cable speedo, I would recommend to do conversion to the tail housing to accept mechanical speedo.
So if you convert the tail housing you don't need anything? No sgi5? What about the vss signal to the ECM does that convert too? I don't care about cruise so I'm not worried about that
The VSS signal from the speedo goes to the ECM, so if the speedo is still driven mechanically it all works like a factory setup. Nothing to do except connect the speedo cable to the modified T56.
I just called the guy, and he told me $550 for everything . I guess his prices went up. But he told me he can work with the customer/ group for a better price. His phone number is 903 527 3335
He did the conversion on my tranny back in 05 or 06 (I do not remember). I only paid for the sleeve and installation, and I think I got it for cheap because I already had the T5 speedo stuff.
first the 550 is with your core i checked about a year ago also theres the abbot cable x box that fixes the problem i cant find the price but i think its $320 im still stuck on doing it mechanical i just like it too look stock i think iv figured it out but i need to find a housing i can build while im driving my car if anybody knows where theres one cheap please let me know
I'm in the same boat, I completed my T56 swap but I'm still stuck with the VSS issue (mechanical speedometer) I have the SGI box and my idea was to wire the T56 VSS wire to the SGI-box then run the output from the SGI box directly to the ECM. I read the VSS wire is either yellow or purple depending on model year and I've tried both and still keep throwing a VSS code. I don't really care about a working speedometer at the moment, I just want the ECM to get the correct codes. Any ideas?
Guys, I had my t56 tail converted to cable drive by a third gen member, user name "alloy". I had the work done around last Christmas. Been working flawless. Cost then was $300 + $20 shipping. Worth every cent. Dean
Ok, Sorry to bump this thread but the cheapest way to have a working speedo with a T56 if you had a factory mechanical speedo is to put in an Autometer Guage if you don't mind changing the stock apperance? Or? The tail shaft to remain stock appearing?
$200 for the autometer, $300 for the tailhousing mod.. Really comes down to your ECM if you're running one. The tailhousing mod will still run on the stock ECM, whereas the T56 VSS will need reprogramming/wiring to work with the older ECMs.
The '85-'89 ECMs used a 2000ppm Square-wave VSS signal, the T56 VSS puts out a 17 pulse per driveshaft revolution Sine-wave. (20,000->50,000 ppm depending on gearing/tire size/etc.) A DRAC will convert the signal for you..
. I guess his prices went up. But he told me he can work with the customer/ group for a better price. His phone number is 903 527 3335 
