Should I run 4 HI regularly ?

[Butch5150]

Is there any benefit to running in 4 hi ? My wife’s FJ Cruiser says in the owners manual to run 4 hi for 10 miles once a month, in a straight line. Basically to keep everything lubricated in the diff and transfer case.
Just wondering if I should do that as my jeep see’s more street time than off road (unfortunately).
This forum rocks ! Thanks for your opinions.

 

[bromel]

The TJ's front axle is live, meaning when you are driving in 2WD the front driveshaft and front diff are always spinning, so everything is already getting lubricated. You should not use 4 hi on pavement, so I see no benefit to engaging it unless you actually need it off-road.

 

[MichaelGH]

I would suggest occasionally getting off-road and engaging 4wd for that purpose. Trail riding, or just any place really off of dry pavement. The problem with dry pavement, in 4wd, is it causes the front and back to fight against each other a little bit. Stress and vibrations from that aren’t great for the drivelines. People have cracked transfer cases wide open with extended dry pavement travels in 4wd. Similarly to driveline vibes from a lift without adjustable control arms or a drop to remedy the situation. Our TJs don’t like it much. Can you get away with it? Very possibly. Can you break your TJ? Very possibly...

 

[L J]

You should not use 4 hi on pavement

4H Position
Four Wheel Drive High Range — Locks the front and rear driveshafts together. Forces the front and rear wheels to rotate at the same speed. Additional traction for loose,
slippery road surfaces.

NOTE: This range should not be used during dry pavement operation

 

[Goatman]

I had an old Nissan PU that handled so much better when in 4HI on dry pavement. Occasionally I would forget to shift back to 2HI at the road and would be amazed how well the truck was handling until I remembered I hadn't pulled out of 4. The

 

[Butch5150]

Thank you all. Great information.
What I’m hearing is I need to go off road more often. Gotcha.

 

[Vinman]

The reason to shift to 4wd when not needed is to prevent the transfer case linkage from seizing due to lack of use.

 

[Rubicon88]

The only thing you should do if not off roading frequently enough is shift into 4hi, then 4lo, then back to 2hi every so often. You don't even need to drive it... it just keeps the linkage from getting stale.

 

[JKP]

You can put it in 4H on pavement, just don't make any turns, straight line only.

 

[AndyG]

Yes you should. Also occasionally lube the linkage ..I use a a spray gel lube by WD-40.

The Savvy cable is money well spent as well.