View Full Version : Replacing TV transfer case to another one
Taxich
08-21-2008, 01:28 PM
Hi all!
Only one question:
Anyone knows is it possible to replace from stok transfer case on my TB`02 to Hummer transfer case with fulltime 4 x 4 ? Or another transfer case with fulltime 4 x 4?
the roadie
08-21-2008, 01:33 PM
The Olds Bravada and some other trailvoys have full time AWD as an option. The transfer case control algorithms are different, and the front axle is engaged all the time so there is no actuator. It would require some computer work with a scan tool to configure the systems with this option, and may require you to enter the VIN of a Bravada to fool the computer.
But that amount of work would be FAR LESS than the immense mechanical hassle of swapping in the transfer case and controls from a different vehicle, because the trailvoy computer would be very unhappy to be talking to something other than what it was programmed to do.
Why is fulltime 4X4 so important to you? If you're in slippery conditions, just switch to A4WD and wait for the slip to happen.
Taxich
08-21-2008, 01:46 PM
A4WD working uncorrectly on the commixed road carpet - snow and asphalt.
And the front axle is connected is unpredictable,too late and it`s not the safe driving .
I have not had an accident nearly because the forward axis was at the wrong time connected.
Taxich
08-21-2008, 01:57 PM
and trailvoy`s stok transfer case doesn`t have transaxle differential.And we can`t using 4x4 on the asphalt road carpet
JamesDowning
08-21-2008, 09:50 PM
As long as the road is slippery enough to warrant 4wd, you should be able to use the system on our vehicles. Just be smart about it and turn it off when the road gets dry or you have to make a sharp turn.
Taxich
08-22-2008, 08:14 AM
Of course-it`s right way. But sometimes I don`t know where is dry and where is ice on road. And sometimes the road is looks like zebra. I wish to be assured in, at least it is a little, in behaviour of the car.
the roadie
08-22-2008, 09:59 AM
Then I believe the Bravada AWD transfer case, and the electronic controls, are your best choice. Or trade the TB for the Bravada, which may be cheaper. Buying the vehicle after you know the road conditions you'll be driving on is usually the best process.
bartonmd
08-22-2008, 10:03 AM
Then I believe the Bravada AWD transfer case, and the electronic controls, are your best choice. Or trade the TB for the Bravada, which may be cheaper. Buying the vehicle after you know the road conditions you'll be driving on is usually the best process.
I thought the Bravada's "AWD" was exactly the same as our "A4WD", except that is the only mode??
Mike
the roadie
08-22-2008, 10:19 AM
I had to go back and read the shop manual to get more data, since I usually spend my time looking at the full-featured transfer case the 4X4 has. You're right in that the clutch pack action is the same when it detects wheel slippage, and it moves the encoder motor to engage the clutch to send more torque to the front. But the theory of operation is a bit different in that it is always sending some torque forward, that is non-zero even at low speed, and increases with speed and throttle position. The algorithms are VIN-dependent (which is why I mentioned a bunch of scan tool work) for type of engine, weight, accessories. And they're adaptive, so the absolute clutch pack position varies as the clutches wear over time. As I understand the theory of our 4X4 transfer case, the A4WD position of the encoder motor is just short of the position needed for sending torque forward, and it only engages the clutches when front to back slippage is detected. Same hardware (except for the LO range we have), but different algorithms. In 4HI and 4LO, our clutch packs are commanded to full torque transfer (as close to locking in the center as we can get).
The SS has a Torsen center diff with entirely different characteristics. I don't have a shop manual that includes the SS, since they didn't make it in 2004.