Captain Morgan
Moderated User
MSD said:
Smart Trac question from s10forum.com
- Thread starter Captain Morgan
- Start date
TurboManiacal
Donating Member
My inclination is that the Smart Track is no different really from our AWD system. Just given a fancy name for marketing purposes.
warmpancakes
New member
smart trac is tied into the abs system in the newer bravadas so you would need the sensors and the complete harness to make it work.
Captain Morgan
Moderated User
cool, thanks guys, ill relay the messages.
Wrong, wrong, wrong......
The Smartrac used in the '98 up Bravada's is not interchangable with the Sy/Ty system. It is completely different, and will only fit on the '96 up 6 bolt tailshaft 4L60E auto trans (unless a special adapter is made to fit the this t-case that is used in the Bravada up to a 700R4). Also, it does NOT interface with the ABS system like some AWD vehicles with traction control do. The Smartrac has a special TCCM (transfer case control module) that looks only at two speed sensors mounted on the t-case that monitor both the front & rear output shaft speeds, and in turn engages a clutch disc pack via an electric stepper motor that sends power to the front output shaft when a speed differential situation exists between the two speed sensors (such as when rear traction is lost). It also looks at data that is downloaded to it via a class 2 multiplex communication circuit from the VCM that is used in these later model vehicles. The data required to operate it includes vehicle identification type (SUV, truck, etc.), throttle position, and vehicle speed from the main VSS sensor on the transmission. This is in order to pull in the front drive when the throttle is depressed to wide open when the vehicle is below 5 mph so that the t-case can get a jump on a situation that will likely cause the rear tires to start spinning from loss of traction. The entire system is fairly complex, and requires wiring up lots of extra items (both a VCM & TCCM module) in order for it to function. I know, because I have already done all the groundwork for a conversion on my '93 4x4 S10 pickup.
The '98 up Bravada uses a single speed Smartrac NV-136 t-case (option code NP4) that uses a non-disengagable front differential (same as the Sy/Ty's do); whereas, the '99 up Jimmy's & Blazer's use a two speed Autotrac NV-236 t-case (option code NP8) that uses a disengagable front differential for added fuel efficiency in cruise conditions (although a non-disengagable front differential can be used with it, and the normal differential switch signal can be simulated via a relay to fool the TCCM). They both use the same physical t-case, except the NV-236 adds low range gearing for offroad use, and it has the added 2WD mode with disengagable front differential. These later generation t-cases are MUCH stronger than the Sy/Ty unit, as they are rated at 2400 ft-lbs of torque (the Sy/Ty unit is only rated at 1500 ft-lbs).
I have an extra NV-236 (option NP8) Autotrac t-case with all associated wiring, control modules, VCM (for download data), and front propshaft for sell for any of you Sy/Ty guys that may be interested. The only thing required to fit it into a Sy/Ty would be a custom adapter from Advanced Adapters (this adapter would probably cost around $250) in order to use a 700R4 trans; otherwise, a '96 up 4L60E 6-bolt tailshaft auto trans with stand alone controller is required (although the VCM that is required for the download data to the TCCM could also be used to control the 4L60E as long as you wire up a few other functions...not really all that difficult, just time consuming). It would be the ultimate t-case conversion for a Typhoon, as well as a Syclone, as it offers the ability to do rear wheel burnouts in the 2WD mode, and then the automatic front output engagement when needed (during rear wheel traction lose) in auto 4WD mode. It is a much more efficient & stronger t-case than the stock Sy/Ty unit. If any of you are interested, I'm asking $600 for the complete setup, and I can be reached at:
travis.loofbourrow@airliquide.com
The Smartrac used in the '98 up Bravada's is not interchangable with the Sy/Ty system. It is completely different, and will only fit on the '96 up 6 bolt tailshaft 4L60E auto trans (unless a special adapter is made to fit the this t-case that is used in the Bravada up to a 700R4). Also, it does NOT interface with the ABS system like some AWD vehicles with traction control do. The Smartrac has a special TCCM (transfer case control module) that looks only at two speed sensors mounted on the t-case that monitor both the front & rear output shaft speeds, and in turn engages a clutch disc pack via an electric stepper motor that sends power to the front output shaft when a speed differential situation exists between the two speed sensors (such as when rear traction is lost). It also looks at data that is downloaded to it via a class 2 multiplex communication circuit from the VCM that is used in these later model vehicles. The data required to operate it includes vehicle identification type (SUV, truck, etc.), throttle position, and vehicle speed from the main VSS sensor on the transmission. This is in order to pull in the front drive when the throttle is depressed to wide open when the vehicle is below 5 mph so that the t-case can get a jump on a situation that will likely cause the rear tires to start spinning from loss of traction. The entire system is fairly complex, and requires wiring up lots of extra items (both a VCM & TCCM module) in order for it to function. I know, because I have already done all the groundwork for a conversion on my '93 4x4 S10 pickup.
The '98 up Bravada uses a single speed Smartrac NV-136 t-case (option code NP4) that uses a non-disengagable front differential (same as the Sy/Ty's do); whereas, the '99 up Jimmy's & Blazer's use a two speed Autotrac NV-236 t-case (option code NP8) that uses a disengagable front differential for added fuel efficiency in cruise conditions (although a non-disengagable front differential can be used with it, and the normal differential switch signal can be simulated via a relay to fool the TCCM). They both use the same physical t-case, except the NV-236 adds low range gearing for offroad use, and it has the added 2WD mode with disengagable front differential. These later generation t-cases are MUCH stronger than the Sy/Ty unit, as they are rated at 2400 ft-lbs of torque (the Sy/Ty unit is only rated at 1500 ft-lbs).
I have an extra NV-236 (option NP8) Autotrac t-case with all associated wiring, control modules, VCM (for download data), and front propshaft for sell for any of you Sy/Ty guys that may be interested. The only thing required to fit it into a Sy/Ty would be a custom adapter from Advanced Adapters (this adapter would probably cost around $250) in order to use a 700R4 trans; otherwise, a '96 up 4L60E 6-bolt tailshaft auto trans with stand alone controller is required (although the VCM that is required for the download data to the TCCM could also be used to control the 4L60E as long as you wire up a few other functions...not really all that difficult, just time consuming). It would be the ultimate t-case conversion for a Typhoon, as well as a Syclone, as it offers the ability to do rear wheel burnouts in the 2WD mode, and then the automatic front output engagement when needed (during rear wheel traction lose) in auto 4WD mode. It is a much more efficient & stronger t-case than the stock Sy/Ty unit. If any of you are interested, I'm asking $600 for the complete setup, and I can be reached at:
travis.loofbourrow@airliquide.com
uuh...
are we sure the newer part- time 4WD NV-236 cases have a viscous assembly in them like the true full time AWD cases do? I have a case from a '99 Astro apart in my shop right now (can't think of the model # offhand, but I'm pretty sure it's an NV-136), and I know that one has a clutch assembly like the older style 4472's...
-only wondering 'cause I'm planning on eventually building a newer body style Ty wanna be kinda thing. If you can just use any dime-a-dozen T- truck parts then that would make it a lot easier
are we sure the newer part- time 4WD NV-236 cases have a viscous assembly in them like the true full time AWD cases do? I have a case from a '99 Astro apart in my shop right now (can't think of the model # offhand, but I'm pretty sure it's an NV-136), and I know that one has a clutch assembly like the older style 4472's...
-only wondering 'cause I'm planning on eventually building a newer body style Ty wanna be kinda thing. If you can just use any dime-a-dozen T- truck parts then that would make it a lot easier
Lowaholic,
The older style Borg Warner 4472 t-case does not have an electric motor activated clutch disk assembly like the '98 up New Process NV-136/236 series of t-cases that are used in the '98 up T-series GM vehicles. The 4472 t-case has a viscous coupling in it that makes it a full time AWD type of t-case. The NV-136/236 t-cases used in the T- series GM trucks & SUV's(and the NV-246 t-case used in the full size GM trucks & SUV's) are considered auto 4WD "on demand" types of t-cases, as they operate in 2WD mode until rear wheel slipage (loss of traction) is detected and then engage the front output drive via a clutch pack in a drum activated by an electric stepper motor. Once rear wheel traction is regained they then release the front output and revert to pure rear wheel drive (2WD) only. The two speed models (NV-236/246) also have low range gearing, and when shifted into 4WD low they lock the clutch disc assembly up and hold the t-case in full front & rear drive output, similar to a part time 4WD t-case (this mode is NOT recommended to be used on pavement as it will drag tires around turns). They also have a 2WD only mode that keeps the t-case in rear wheel drive only at all times, and disengages the front differential for added fuel efficiency on the highway. It is actually a very versatile system, and would work extremely well in a Typhoon (although the low range gearing wouldn't really be usefull for it (unless offroad capability were desired in a special Hot Rod 4x4 truck that has a high powered engine that could also benefit from the auto 4WD function for on road traction during launch!).
Oh by the way, there is also a late model New Process t-case used in the Cadillac Escalaide that is a viscous coupling full time AWD type of system, but once again, it would not be a very fuel efficient setup for a Sy/TY.
Since you are thinking of building a late model body style type of "wanna be Ty", then the setup I have for sell is IDEAL for that, as I have all of the wiring to make it function from a '99 Jimmy that had the NV-236 in it (it was the donor vehicle that I got the t-case from), and I also have a VCM from a full size V8 truck that had the NV-246 with Vortec 5.7 V8 and its matching TCCM (which has a separate output for a 4WD lamp that the T-series TCCM does not have). It would be an easy swap with a Vortec 5.7 V8 in the vehicle with this auto 4WD combination using the late model 4L60E 6-bolt tailshaft auto trans, and with a Vortech supercharger used on that engine, would net a late body style type of "wanna be Ty" that has around 450 hp but with the fuel efficiency of the stock 5.7 Vortec V8 (and much less complexity & cost when compared to the turboed early Ty's). That is by the way, the combination that I am building in my '93 4x4 extended cab S10 truck.
Just food for thought!
tloof
The older style Borg Warner 4472 t-case does not have an electric motor activated clutch disk assembly like the '98 up New Process NV-136/236 series of t-cases that are used in the '98 up T-series GM vehicles. The 4472 t-case has a viscous coupling in it that makes it a full time AWD type of t-case. The NV-136/236 t-cases used in the T- series GM trucks & SUV's(and the NV-246 t-case used in the full size GM trucks & SUV's) are considered auto 4WD "on demand" types of t-cases, as they operate in 2WD mode until rear wheel slipage (loss of traction) is detected and then engage the front output drive via a clutch pack in a drum activated by an electric stepper motor. Once rear wheel traction is regained they then release the front output and revert to pure rear wheel drive (2WD) only. The two speed models (NV-236/246) also have low range gearing, and when shifted into 4WD low they lock the clutch disc assembly up and hold the t-case in full front & rear drive output, similar to a part time 4WD t-case (this mode is NOT recommended to be used on pavement as it will drag tires around turns). They also have a 2WD only mode that keeps the t-case in rear wheel drive only at all times, and disengages the front differential for added fuel efficiency on the highway. It is actually a very versatile system, and would work extremely well in a Typhoon (although the low range gearing wouldn't really be usefull for it (unless offroad capability were desired in a special Hot Rod 4x4 truck that has a high powered engine that could also benefit from the auto 4WD function for on road traction during launch!).
Oh by the way, there is also a late model New Process t-case used in the Cadillac Escalaide that is a viscous coupling full time AWD type of system, but once again, it would not be a very fuel efficient setup for a Sy/TY.
Since you are thinking of building a late model body style type of "wanna be Ty", then the setup I have for sell is IDEAL for that, as I have all of the wiring to make it function from a '99 Jimmy that had the NV-236 in it (it was the donor vehicle that I got the t-case from), and I also have a VCM from a full size V8 truck that had the NV-246 with Vortec 5.7 V8 and its matching TCCM (which has a separate output for a 4WD lamp that the T-series TCCM does not have). It would be an easy swap with a Vortec 5.7 V8 in the vehicle with this auto 4WD combination using the late model 4L60E 6-bolt tailshaft auto trans, and with a Vortech supercharger used on that engine, would net a late body style type of "wanna be Ty" that has around 450 hp but with the fuel efficiency of the stock 5.7 Vortec V8 (and much less complexity & cost when compared to the turboed early Ty's). That is by the way, the combination that I am building in my '93 4x4 extended cab S10 truck.
Just food for thought!
tloof