DENALI 2.0 / 2WD
Real long read, may want to print out and take to your bathroom break....lol
Part 1 = Hysterisis
Part 2 = Out with the old
Part 3 = Convert me & save me [non-religious]
Part 4 = In with the new
Part 5 = Loose your IFS grip
Part 1 THE VICTIMS………
99-2006 [GMT800 series],
Yukon Denali, with the BW 4481/**/ Series “All the time” AWD -
Sierra Denali/C3, with the NVG149/BW’s? with “Part time” AWD
Yukon+[XL]. Tahoe, Suburban? With the BW44**/82-84/** with Full time 4WD
Who all suffer from popular front drive train growls, hums, squeaks, vibrations, poor gas mileage or premature wear, or frequently use HD highway towing.
Everyday use, when on road driving, keeps a lot of mechanical parts rotating, sling mud like a corrupt politician.!!!!!!!!!!!!!
In my case, I have had the dreaded light acceleration growl for about 3-5000 miles. Split the diff, found bad side carrier bearings, but still had some concerning noises and was not sure if it was TransCase related, so thought a good time to pop it all out to inspect. Since I travel long distance and sometimes tow heavy loads with not much if any 4WD needs, be a good time to convert.
THE GOALS………..
** Find a suitable replacement Transfer Case [TC], that allows the vehicle to be switched back to, 2 wheel drive, while still retaining the option for 4WD type capabilities.
** Find a unit that is close in specs and size, that would not require a lot of modifications
** Complete R&R for the average DIY’er
** Make a cost effective/selective replacement and while making the vehicle have factory restorability.
** Efficient installation possible as 1 man R&R
Looks to be, four potential options…
1/ Manually shifted transfer case with front drive shaft removed
2/ “ “ “ “ “ front CV shafts removed
3/ “ “ “ “ “ front IFS right axle swap to 12v actuator
4/ Electrically shifted TC with 12v controlled IFS axle actuator
THE CONCERNS……..
** The effects of the Active Brake/Traction Control [ABC] and Engine Torque
** Management [ETM] my abbreviations for laypersons, not the industries.
** The controllment / adjustability and securement of the shifting mechanism.
** The loss of automatic rear to front power distribution/ biasing, currently
achieved by AWD
THE GUINEA PIGS……
To understand what you need, you have to know what your have!
For the sake of this writing, I will be describing, my 2005 YD, with the BW 4481, which has the all mechanical, “open differential”, planetary type TC.
In normal driving, the power output is approx -70% rear/ 30+% front.
AWD is achieved by a always active, power redistributing [biasing] from F-R/R-F by the open diff in the TC, meaning when the TC senses rear wheel slip, [activates ABC], the differential in the case, automatically sends more power to the front wheels, via the front output shaft on the TC.
The other aspect of AWD is the ability of the power to be distributed, from the spinning wheel with less traction, to the other side. This is achieved by Active Brake/Traction Control, in which the computer senses thru the WSS [wheel speed sensor] the difference in speed.
The third aspect of AWD is Engine Torque Management , in which, the computer senses, wheel spin, it reduces torque to not over heat the brakes that are controlling traction.
Since my setup, has NO electrical control/measuring on the TC, just the ABC/ETM, the best suitable option to convert was a similar, “mechanical” TC.
With that said………
I will be going with option 1 to start and working on 2, 3 and 4
Step 1, was to find a TC that was close on it’s specification.
Most of the TC’s had Hollander ‘Interchangeability” as far as mounting goes. The 4481 mates to the 4L65E trans, which is similar in specs to it’s little sister the 4L60E, having a 27 spline output shaft.
The BW4481, has a front case mating surface to rear output shaft case measurement of 19.5”. [sorry to you metric heads]
It also has a 32 spline output shaft, with a female front output.
The difference between the front case face and the front shaft output seal face was 3.5” [ in parallelism]
The NVG series has a longer front case half, which in turn makes the front face to front output face, 1” further rearward. However, the front mating to rear seal remained the same 19.5”. It also has the 27 in/32 out and female front shafts.
It’s closest sister part in platform, would be the New Process / NVG 246. Since the 246 has 2WD and a Auto 4WD option, I looked at that unit as a potential replacement. Unfortunately, the ‘Auto’ 4wd feature is controlled by a clutch pack that is electronically controlled by the monitoring of other speed sensors on the front and rear output shaft of the TC. The 2002 an up also have a star shaped shift mounting fork, which made a quick resolve, more complicated.
Since mechanically it would be a ‘bolt in’, I couldn’t justify the installing / wiring / re-flashing a TC control module [TCCM] etc, for this hack.
Next up was the NVG 261 / 263 series which both have a 2WD/PT- 4WD feature
The 263 sparked, immediate interest as it is a heavy duty unit and uses a electrically controlled encoder [actuator] motor to shift. Unfortunately again, because of it’s heavy duty status, it was only available to the 4L80E and Allison.
Moving on to the 261.…..
The 261 was available in three different models, but are only available in manually floor shifted trucks.
** 261 LD, which mates behind the 4L60E in 1500 series trucks
** 261HD, “ “ “ “ 4L80/Ally1000 in the 1500/2500 trucks
** 261XHD “ “ “ “ Ally 1000+? 6 Spd Auto
And the ’Wiener” is………….
The 261 LD a direct bolt in for the 2WD side with some mods needed for shifting, with the potential with heavier duty custom build enhancements
My parts choice vehicle is a 2004 Silverado ExCab1500 Z71 with 84K mi. ©
[Still not sure how there is a Z71 with a floor shift T/C]
My local yard salvage yard, has one of the best websites with Hollander parts interchange listings I have seen. A little different from Car-Part, but same idea, except they actually show pictures of vehicles and one of those pics is of the RPO tag in the glove box
By having viewing access to this tag, I was able to see exactly what options the vehicle had, without a lot of running around or asking questions.
NOW…..
Knowing what my YD has [did I mention that earlier?] I knew I was going to need a GT4 axle ratio [373]. My YD also had option JL4, [ABC]
Moving on to the different TC case length issue. I knew I would be 1” further away from the pinion yoke. Most drive shafts are measured by “weld to weld” of the main tube. My YD being 25”. A little research found that there were some in the platform that were 26”…..yea, me!!.
However, the next obstacle was the JL4/ABC.. Coincidentally the 04 1500 had the 26” Drv Shft but was not JL4, so it was worth a looksi…Same pinion yoke…. Same u-joints….. Same T/C slip yoke… Once my factory shaft was out, the only difference is the tube thickness. [yep the highly accurate, ping test…lol] So, worth a shot, eh?. I would have to equate this to the ABC/ETM were there is added torque being applied that is transferred sending power back rearward when applied, required a stronger gauge tube. Strangely the 4WD with High/Low and Auto does not require the heavier tube wall.
Anyhoo……….
A little custom shift braketry….and some effort on the ease of installation side, in the form of a floor jack mod, some Weaties diluted in coffee and wha-laa… about three hours and I’m singin a Willie Nelson tune with MotorHead vocals.
Now preliminarily, I choose to go the front shaft delete, with CV ½’s shafts still in for the time being while Beta Test-beatin. I due plan on removing the shafts and eventually will be looking at either rebuilding my front diff with a electrically actuated right housing shaft and gears or maybe just swapping a complete assembly.
But if anyone chooses to go this minimally invasive physical effort to have the need for 4WD, it would take about less than 5-15 mins to drive up on ramps, shift into 4x/2x and pop the front shaft or axles back in, or push a button
BE FORWARNED…………
2WD is 2WD, but this conversion it will only allow part time 4WD, meaning 50/50 split only >>OFF ROAD> SNOW> SAND or situations were traction can be lost..
This is not intended for ON ROAD USE and will harm or break drive train components.©
Real long read, may want to print out and take to your bathroom break....lol
Part 1 = Hysterisis
Part 2 = Out with the old
Part 3 = Convert me & save me [non-religious]
Part 4 = In with the new
Part 5 = Loose your IFS grip
Part 1 THE VICTIMS………
99-2006 [GMT800 series],
Yukon Denali, with the BW 4481/**/ Series “All the time” AWD -
Sierra Denali/C3, with the NVG149/BW’s? with “Part time” AWD
Yukon+[XL]. Tahoe, Suburban? With the BW44**/82-84/** with Full time 4WD
Who all suffer from popular front drive train growls, hums, squeaks, vibrations, poor gas mileage or premature wear, or frequently use HD highway towing.
Everyday use, when on road driving, keeps a lot of mechanical parts rotating, sling mud like a corrupt politician.!!!!!!!!!!!!!
In my case, I have had the dreaded light acceleration growl for about 3-5000 miles. Split the diff, found bad side carrier bearings, but still had some concerning noises and was not sure if it was TransCase related, so thought a good time to pop it all out to inspect. Since I travel long distance and sometimes tow heavy loads with not much if any 4WD needs, be a good time to convert.
THE GOALS………..
** Find a suitable replacement Transfer Case [TC], that allows the vehicle to be switched back to, 2 wheel drive, while still retaining the option for 4WD type capabilities.
** Find a unit that is close in specs and size, that would not require a lot of modifications
** Complete R&R for the average DIY’er
** Make a cost effective/selective replacement and while making the vehicle have factory restorability.
** Efficient installation possible as 1 man R&R
Looks to be, four potential options…
1/ Manually shifted transfer case with front drive shaft removed
2/ “ “ “ “ “ front CV shafts removed
3/ “ “ “ “ “ front IFS right axle swap to 12v actuator
4/ Electrically shifted TC with 12v controlled IFS axle actuator
THE CONCERNS……..
** The effects of the Active Brake/Traction Control [ABC] and Engine Torque
** Management [ETM] my abbreviations for laypersons, not the industries.
** The controllment / adjustability and securement of the shifting mechanism.
** The loss of automatic rear to front power distribution/ biasing, currently
achieved by AWD
THE GUINEA PIGS……
To understand what you need, you have to know what your have!
For the sake of this writing, I will be describing, my 2005 YD, with the BW 4481, which has the all mechanical, “open differential”, planetary type TC.
In normal driving, the power output is approx -70% rear/ 30+% front.
AWD is achieved by a always active, power redistributing [biasing] from F-R/R-F by the open diff in the TC, meaning when the TC senses rear wheel slip, [activates ABC], the differential in the case, automatically sends more power to the front wheels, via the front output shaft on the TC.
The other aspect of AWD is the ability of the power to be distributed, from the spinning wheel with less traction, to the other side. This is achieved by Active Brake/Traction Control, in which the computer senses thru the WSS [wheel speed sensor] the difference in speed.
The third aspect of AWD is Engine Torque Management , in which, the computer senses, wheel spin, it reduces torque to not over heat the brakes that are controlling traction.
Since my setup, has NO electrical control/measuring on the TC, just the ABC/ETM, the best suitable option to convert was a similar, “mechanical” TC.
With that said………
I will be going with option 1 to start and working on 2, 3 and 4
Step 1, was to find a TC that was close on it’s specification.
Most of the TC’s had Hollander ‘Interchangeability” as far as mounting goes. The 4481 mates to the 4L65E trans, which is similar in specs to it’s little sister the 4L60E, having a 27 spline output shaft.
The BW4481, has a front case mating surface to rear output shaft case measurement of 19.5”. [sorry to you metric heads]
It also has a 32 spline output shaft, with a female front output.
The difference between the front case face and the front shaft output seal face was 3.5” [ in parallelism]
The NVG series has a longer front case half, which in turn makes the front face to front output face, 1” further rearward. However, the front mating to rear seal remained the same 19.5”. It also has the 27 in/32 out and female front shafts.
It’s closest sister part in platform, would be the New Process / NVG 246. Since the 246 has 2WD and a Auto 4WD option, I looked at that unit as a potential replacement. Unfortunately, the ‘Auto’ 4wd feature is controlled by a clutch pack that is electronically controlled by the monitoring of other speed sensors on the front and rear output shaft of the TC. The 2002 an up also have a star shaped shift mounting fork, which made a quick resolve, more complicated.
Since mechanically it would be a ‘bolt in’, I couldn’t justify the installing / wiring / re-flashing a TC control module [TCCM] etc, for this hack.
Next up was the NVG 261 / 263 series which both have a 2WD/PT- 4WD feature
The 263 sparked, immediate interest as it is a heavy duty unit and uses a electrically controlled encoder [actuator] motor to shift. Unfortunately again, because of it’s heavy duty status, it was only available to the 4L80E and Allison.
Moving on to the 261.…..
The 261 was available in three different models, but are only available in manually floor shifted trucks.
** 261 LD, which mates behind the 4L60E in 1500 series trucks
** 261HD, “ “ “ “ 4L80/Ally1000 in the 1500/2500 trucks
** 261XHD “ “ “ “ Ally 1000+? 6 Spd Auto
And the ’Wiener” is………….
The 261 LD a direct bolt in for the 2WD side with some mods needed for shifting, with the potential with heavier duty custom build enhancements
My parts choice vehicle is a 2004 Silverado ExCab1500 Z71 with 84K mi. ©
[Still not sure how there is a Z71 with a floor shift T/C]
My local yard salvage yard, has one of the best websites with Hollander parts interchange listings I have seen. A little different from Car-Part, but same idea, except they actually show pictures of vehicles and one of those pics is of the RPO tag in the glove box
By having viewing access to this tag, I was able to see exactly what options the vehicle had, without a lot of running around or asking questions.
NOW…..
Knowing what my YD has [did I mention that earlier?] I knew I was going to need a GT4 axle ratio [373]. My YD also had option JL4, [ABC]
Moving on to the different TC case length issue. I knew I would be 1” further away from the pinion yoke. Most drive shafts are measured by “weld to weld” of the main tube. My YD being 25”. A little research found that there were some in the platform that were 26”…..yea, me!!.
However, the next obstacle was the JL4/ABC.. Coincidentally the 04 1500 had the 26” Drv Shft but was not JL4, so it was worth a looksi…Same pinion yoke…. Same u-joints….. Same T/C slip yoke… Once my factory shaft was out, the only difference is the tube thickness. [yep the highly accurate, ping test…lol] So, worth a shot, eh?. I would have to equate this to the ABC/ETM were there is added torque being applied that is transferred sending power back rearward when applied, required a stronger gauge tube. Strangely the 4WD with High/Low and Auto does not require the heavier tube wall.
Anyhoo……….
A little custom shift braketry….and some effort on the ease of installation side, in the form of a floor jack mod, some Weaties diluted in coffee and wha-laa… about three hours and I’m singin a Willie Nelson tune with MotorHead vocals.
Now preliminarily, I choose to go the front shaft delete, with CV ½’s shafts still in for the time being while Beta Test-beatin. I due plan on removing the shafts and eventually will be looking at either rebuilding my front diff with a electrically actuated right housing shaft and gears or maybe just swapping a complete assembly.
But if anyone chooses to go this minimally invasive physical effort to have the need for 4WD, it would take about less than 5-15 mins to drive up on ramps, shift into 4x/2x and pop the front shaft or axles back in, or push a button
BE FORWARNED…………
2WD is 2WD, but this conversion it will only allow part time 4WD, meaning 50/50 split only >>OFF ROAD> SNOW> SAND or situations were traction can be lost..
This is not intended for ON ROAD USE and will harm or break drive train components.©
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