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Transfer Case Lubrication while Flat Towing with Lock Out Hubs

dart70LA

NAXJA Forum User
NAXJA Member
Location
Santee, CA
Please be patient with me on this one: I searched "Flat tow hubs", and a few variations of the same idea, and did not find anything related to TC case questions.

I am preparing my rig(1999 Cherokee, original NP231 T-Case) to flat tow behind my truck/camper and know that the factory procedure is to put the TC in neutral, and transmission in Park. But I added Yukon Spin Free locking hubs(bronco style) a couple of years ago.

1999 Cherokee, original NP231 T-Case.

Without locking hubs, the front axle would spin the driveshaft and sling oil around the case. But with Hubs unlocked that won't happen. The only fluid at the top end would come from the TC oil pump.

Is that enough lubrication?

My gut instinct is it better be, otherwise I think I would have trouble when it is in 2WD and I have the hubs unlocked while driving, let alone while flat-towing.
 
Yes - The oil pump is spline driven off the rear output & only turns when the rear output is turning.
 
Don't sweat it. Nothing is lubricated off the front shaft turning over some oil slinging around via the chain. The NP231 uses a gerotor pump driven off the rear output shaft to pump lubrication throughout the case.
 
Don't sweat it. Nothing is lubricated off the front shaft turning over some oil slinging around via the chain. The NP231 uses a gerotor pump driven off the rear output shaft to pump lubrication throughout the case.

The transfer case doesn't mind being towed at all. The 2001 XJ's NP231 has been towed almost a 100,000 miles behind behind our motorhome.
The 1997's NP242 has been towed around 30,000 miles.
 
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