4x4 needs improvement, suggestions needed

[ediddily]

07 XLT

As the title states I feel as though the front drivetrain doesn't really work all that well. I know everything "works" to get into 4x4, 4A and transfer case put power to the front, but when driving on ice/snow and the rear end start slipping, the front end never really "grabs."

I recently changed transfer case oil (Mercon V), installed a high flow intake and a Detroit Truetrac LSD in the rearend and that seems to just throw all the power to the rear end causing serious spinouts or even getting stuck in really "dumb" places and no power to the front drivetrain to get out of these "dumb" situations.

My question, is there anything I can do to improve the power distribution to the front end? Perhaps install a auto locker or LSD in the front? (Front is currently open stock)

 

[whtbronco]

Since there's been no response I'll through my 2c in.

It looks like that's a BW4417 which is another Torque On Demand(TOD) transfer case just like my BW4416. In 4High and 4Low I believe it should be a 50/50 split. If it's not then there is something broken I believe. The front end won't feel locked in with an open diff like the rear, but it should still have the same power as the rear though you may just be spinning one tire up front.

Assuming it also has an AWD setting, maybe it's 4A on your switch, that's what you get with the crappy TOD setup. With AWD selected you are generally putting most of the power to the rear end until there's slipping and the clutches engage sending more power to the front end. In 4H and 4L the clutches should be engaged/locked all the time. The clutches allow the TOD transfer cases to change to some extent where the power goes with a bias to the rear end, but only in AWD at least all that I have driven. I have found that AWD is okay when the roads are wet, but in the snow and ice I believe it's flat out dangerous if the driver knows how to drive. I also have an LSD rear, but I do not have any form of traction/stability control, I refused to. I had AWD nearly pull me off the road. You can test this in the snow by using the 4A setting and hit the throttle enough to spin the tires off the line. I suspect you'll feel the rear start spinning and then the front will engage. If you try again with the same amount of throttle in 4H you'll just feel it pull front and rear together and it will not change.

 

[ExplorerTom]

I’d make sure the front is actually engaging.

On dry pavement, put it in 4hi and start driving in tight circles (in an empty parking lot or someplace). Does it turn smoothly or is the driveline binding up causing the front to sorta push out. Repeat in 2wd. Does it behave differently (normally)?

If it’s not binding up, the front axle isn’t engaging.

The vacuum system could be an issue- although when vacuum is removed (like a hole in a line) then the front hubs engage.

Put the front on jackstands. Are the wheels locked with the engine off? They should be. Do they spin with the engine running?