Towing a 2001 behind an RV - questions

mitchntx · March 2, 2014

I'm looking at a 2001 GMC that has 247K miles on it and the owner claims that the majority are tow miles behind his RV.

The odometer is data stored in the ECM. The miles still rack up using constant power to the ECM?

Also, I've always been taught that towing without disconnecting the driveshaft was hard on the transmission. I assume that still holds true?

On a 4WD with auto hubs, the drive line has to be disconnected as well? Or just selecting 2WD unlocks the front hubs and no engagement of teh front DL and transfer case?

Edited March 2, 2014 by txab

Silverado4x4 · March 2, 2014

With a 4x4 you put the transfer case in neutral for flat towing or dolly towing no need to remove the driveshaft, as far as the high mileage and he claims it from towing behind his RV be careful with that one as if he towed with the key on and "T" case in neutral the mileage will rack up but if he had the key off then the miles wont rack up on the odometer. I would ask him that question. I would doubt he had the key on while he was towing all those miles as the battery would be dead with the key on all that time.

Keep in mine with the T case in neutral even with the transmission in park the vehicle will still roll.

Edited March 2, 2014 by Silverado4x4

mitchntx · March 2, 2014

2001 electronic cases don't have a neutral, right?

Silverado4x4 · March 2, 2014

Yes they do as you just push the 2wd and 4low buttons together and hold for about 10-20 seconds and the T case goes into neutral.

You have to put the transmission in neutral press the buttons for about 10-20 seconds move the trans lever to reverse then drive then to park. I think that's how I remembered.

Edited March 2, 2014 by Silverado4x4

mitchntx · March 2, 2014

I didn't know. Good info.

So the 247K miles, many towed behind an RV seems awfully suspect as was said earlier.

Does the odo only get a signal from a reluctor in the trans or would it also pick it up from an ABS wheel sensor?

intheburbs · March 3, 2014

I don't see how the truck would rack up miles when being towed behind an RV. Ignition off, computer off, no miles registered.

Regarding shifting the transfer case into neutral - this is from the 01 Tahoe/Suburban manual:

To shift the transfer case to NEUTRAL, first make sure
the vehicle is parked so that it will not roll:
1. Set the parking brake.
2. Start the vehicle or turn the ignition to RUN.
3. Connect the vehicle to the towing vehicle.
4. Put the transmission in NEUTRAL (N).
5. Shift the transfer case to 2HI.
6. Simultaneously press and hold the 2HI and 4LO buttons for 10 seconds. The red NEUTRAL light will come on when the transfer case shift to NEUTRAL is complete.
7. Shift the transmission to REVERSE ® for one second, then shift the transmission to DRIVE (D) for one second.
8. Turn the ignition to OFF.
9. Place the transmission shift lever in PARK (P).
10. Release the parking brake prior to towing.