Just acquired a 93 Geo Tracker 2 door to tow behind our RV. They say you cannot flat tow with the Auto hubs. Why not. It is a 4X4 standard tranny. Has anyone tried towing with the Auto hubs?
Thanks, Don

I have not tried flat towing with either type. I think the concern with towing auto hubs is that they may lock or become unlocked while backing.

The autohubs lock when the CV axle drives them - when you set up for flat towing, you select Neutral in the transfer case, and at that point the front & rear drive shafts are locked together, the rear wheels will drive the rear axle, the rear axle will drive the rear drive shaft, which will drive the front drive shaft, and the front axles, locking the hubs - this creates a problem because the front axle turns faster than the rear axle in turns.

The end result will be drive train damage.

The good thing is it is simple to switch from auto hubs to manual hubs. Unbolt the auto hubs (6 bolts each hub), bolt the new manual hubs on with new bolts and cone washers. Done.
I do recommend using Loc-Tite and properly torquing the hub bolts, to make sure they don't loosen up over time.

Cone washers are required with OEM style Aisin hubs, I've never seen an aftermarket hub with the tapered holes to accept the cone washers.

Cone washers are required with OEM style Aisin hubs, I've never seen an aftermarket hub with the tapered holes to accept the cone washers.

Me neither. I was assuming he would use stock trackick manual hubs to replace the auto hubs...hence the reason I mentioned the cone washers.

You could pull the rear shaft, then the front won't turn & cause problems.

Yes, you could, but, and correct me if I'm wrong - the idea behind towing a "dinghy" behind your RV is the convenience of having a smaller vehicle to "run around" in - doesn't the need to get under that dinghy to remove/replace the drive shaft, every time you need to use it negate that convenience?

Please also bear in mind that the drive shafts have slip yokes so that removal will typically result in a loss of lubricant.

Suddenly, having a Suzuki as a dinghy doesn't seem so convenient now, maybe a Vespa instead?

Let me speak from my personal experience towing my Sidekick...4x4, manual trans, auto hubs...
As was stated earlier, placing the trans case in N locks the outputs together, so the front driveshaft, diff, half shafts will also turn.  From my experience, this really isn't a huge problem, IF your cv boots are in good condition.  I had a torn boot on the driver's side half shaft...I made it about 150 miles and got flagged down because it looked like the Kick was on fire....smoke rolling off the front left wheel.  I got out to investigate and there is black grease slung all down the side of the rig, and the left outer CV joint was completely toasted.  As in, all my years of wrenching, I have never seen a CV joint that looked like this thing!  Through messing with that I figured out the driveshafts were locked together, so placed the case in 2 Hi, pulled the rear driveshaft loose and tied it up underneath and continued my trip.  On the way home I left the shaft attached and just left the case in 2HI.  My conclusion is that the front locking hubs have nothing to do with that problem.  Leaving the transfer case in 2HI actually leaves you with fewer parts moving, so as such, less heat, less friction, etc.  Seems to me this would be much preferred to pulling with it in N.  Now ideal situation?  Twin stick shifter on the case you so you select N on both sticks and in theory transmit no movement into the transmission.