towing a 78 cj5 3spd 4wd on the freeway for 1800 miles. Will it damage the tranny?
My bro-in-law recently told me that towing the CJ5 on a tow bar may cause some damage to the tranny. The 3spd can usually handle 60-65 on the freeway and I plan on towing at that speed. He recommended getting a dolly or a car carrier but uhaul wants 300-600 for them. A tow bar is only 150.
You do need to disconnect the rear drive shaft and unlock the front hubs. I’ll explain why:
The gears inside a transfer case (gearbox that the drive shafts come out of) are lubricated by an oil slinger. Think of it as a fan with part of the blades dipped in the transmission fluid. As the slinger spins, all the parts are lubricated.
On a 78, the oil slinger is connected to the transfer case input. As the engine turns, it rotates gears and shafts in the transmission, which in turn rotate the input shaft in the transfer case. Put your transfer case into neutral and the engine still rotates the input shaft and lubes your transfer case.
Now consider the towing scenario. Your transfer case is in Neutral and the engine is off. As you tow, the wheels turn the drive shafts, which in turn drive the output components of your transfer case. The input components to the transfer case do not rotate since the engine is off. This includes the oil slinger – it sits motionless while your driveshafts rotate the oil-free transfer case output components at 60-65 MPH.
The solution, as mentioned, is to remove the rear drive shaft and unlock the front hubs. These two steps mechanically separate the transfer case from any rotating inputs. Then you are free to flat-tow your Jeep without worry of damage to the drive train.
I hope that clears things up. It’s a bit difficult to describe.
