Four wheel drive on dry pavement

[kenmyfam]

Re: Four wheel drive on dry pavement

I haven't made it to Great Brittain yet. We are planning a trip to Germany and France next year, maybe we can squeeze in a little extra time.

Theres some great sightseeing over there in Great Britain but don't expect good weather or you will be disappointed. I have driven through France and Germany several times. The Loire Valley and the South west coast of France (Bordeaux region) are really nice.
I am sure you will enjoy your trip.

 

[_brad_]

Re: Four wheel drive on dry pavement

Brad -- any of the AWD or automatic 4WD systems have either a viscous coupling or a differential in the transfer case so those systems can be run on dry pavement without driveline binding. However, most automatic 4WD systems can be switched from AUTO to LOCK which locks that differential. Now you have the same situation as with a manual 4WD system.

Ahh I see I see. Good to know, thanks!

 

[Matt S]

Re: Four wheel drive on dry pavement

2002+ Ford trucks (including Ranger) went to full time live front axles, with a borg warner transfer case that has an electric lockup solenoid to join the front to the rear. This means the front axle is always spinning in motion, and flipping the switch joins the front to the rear thus providing power to the fronts. My brothers '05 F150 4.6L (he's also a regional service director for a few Ford dealers) locks all tires in any 4x4 setting, sharp turns result in the inside tires chirping/skipping as they try to spin the same as the outside tires and the rear tires. My 05 Ranger is the same way. Yes, the front has a locking differential and if you are not under power while turning it's just like a standard "locker" rear but there is no forgiving differential between the front axle and the rear. So at least one of the front tires will try to spin the same speed as at least one of the rear tires causing stress on the transfer case and the entire driveline between the front and rear differentials.

What he said is if you didn't break anything, you're fine. Also the comment about speed is not correct. 4x4 hi is designed for hwy speeds and there is no issue with running 65mph. We drove almost exclusively in 4x4 on the Yukon going to Alaska last winter in is F150 without a problem at average speeds of 45mph to 65mph. BUT..on dry pavement you already know the issue if you had an emergency swerve maneuver to do. The truck will pitch and roll.

In a straight line, and with wide sweeping turns locking 4x4 is not a big deal. Short turns where there is high friction between the tires and the road is the problem. He's had to tell many an owner who forgot it was on and did a U-turn in a boat ramp causing an axle to break (either drive line axle or wheel axle - more common the transfer case shears a gear because the owner stepped on the gas in a sharp turn on dry pavement with 4x4 on) that they are SOL on the warranty. Ford just won't pay him for that work when the adjuster comes out.

And when it's the middle of July in California..it's hard to claim you were in the snow when it broke

 

[pgdignan]

Re: Four wheel drive on dry pavement

From the sounds of it you probably got the hubs a bit warm and might have put a little differential wear on the front tires but nothing in your description would likely cause any damage.

 

[srothfuss]

Re: Four wheel drive on dry pavement

2002+ Ford trucks (including Ranger) went to full time live front axles...

My Jeep is set up similar but the transfercase has an open differential in it so that I can select a setting for full time 4wd and still have the ability to turn really sharp corners and drive in all seasons.

 

[mrfixitman40]

Re: Four wheel drive on dry pavement

2002+ Ford trucks (including Ranger) went to full time live front axles

really why are there vacuum lines to the front hubs ?? and the front end was the same from 1997-2004(heritage model only) then 2004-present are the same.
SECTION 308-07A: Four Wheel Drive (4WD) Systems 2005 F-150 Workshop Manual
DESCRIPTION AND OPERATION Procedure revision date: 03/08/2006

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Four Wheel Drive (4WD) Systems Printable View (68 KB)
Mechanical Shift

The Borg-Warner 44-06 manual shift transfer case is a 3-piece aluminium design. The unit transfers engine power from the transmission to the front and rear axles. Under normal driving conditions the unit is in 2-wheel drive high (2H), but when desired, the operator may shift into 4-wheel drive high (4H) or 4-wheel drive low (4L). The transfer case is shifted manually. The unit is lubricated by a positive displacement fluid pump that channels fluid flow through holes in the rear output shaft.

Principles of Operation

The mechanical shift on the fly (MSOF) system is a manual shift 4WD system that allows the operator to chose between 2 different 4x4 modes as well as 2-wheel drive and neutral. The operator can switch between 2WD and 4H mode at speeds up to 88 km/h (55 mph). To engage or disengage 4L range, the vehicle speed must be less than 5 km/h (3 mph), the brake pedal pressed and the transmission must be in NEUTRAL (or the clutch pedal pressed in manual transmission vehicles).

The transfer case is equipped with an electromagnetic clutch which is located inside the case. This clutch is used to synchronize the front driveline. When the manual shift lever is moved, this activates the mode indicator switch, triggering the 4x4 module (PCM) to energize the electromagnetic clutch. When the transfer case front and rear output shafts are synchronized, the spring loaded lockup collar mechanically engages the mainshaft hub to the drive sprocket. Finally, the front axle integrated wheel ends (IWEs) are engaged and the electromagnetic clutch is deactivated.

Feature Inputs:
Mode indicator switch.
Wheel speeds (via CAN communication).
Feature Outputs:
Transfer case synchronization clutch.
Integrated wheel end (IWE) vacuum solenoid.
4WD mode (via CAN input to PCM).
Cluster Indicators (via CAN communication).
Electronic Shift

The Borg-Warner electronic shift transfer case is a 3-piece aluminium design. The unit transfers engine power from the transmission to the front and rear axles. Under normal driving conditions the unit is in 2-wheel drive high (2H), but when desired, the operator may shift into 4-wheel drive high (4H) or 4-wheel drive low (4L). The transfer case is shifted electronically. The unit is lubricated by a positive displacement fluid pump that channels fluid flow through holes in the rear output shaft.


Principles of Operation

The electronic shift on the fly (ESOF) system is an electronic shift system that allows the operator to choose between 2 different 4-wheel drive modes as well as 2-wheel drive. The operator can switch between 2WD and 4H mode at speeds up to 88 km/h (55 mph). To engage or disengage 4L range, the vehicle speed must be less than 5 km/h (3 mph), the brake pedal pressed and the transmission must be in NEUTRAL (or the clutch pedal pressed in manual transmission vehicles).

The transfer case is equipped with an electromagnetic clutch which is located inside the case. This clutch is used to synchronize the front driveline. When the mode select switch (MSS) on the instrument panel is turned, the 4x4 module (PCM) activates the electromagnetic clutch and powers the transfer case shift motor. When the shift motor reaches the desired position, as determined by the contact plate position inputs to the 4x4 module (PCM), power to the shift motor will be removed. When the transfer case front and rear output shafts are synchronized, the spring loaded lockup collar mechanically engages the mainshaft hub to the drive sprocket. Finally, the front axle integrated wheel ends (IWEs) are engaged and the electromagnetic clutch is deactivated.

Feature Inputs:
Mode select switch (MSS).
Wheel speeds (via CAN communication).
Contact plate position inputs A, B, C, D (grounded when closed, open circuit when open).
Transmission neutral.
Brake ON/OFF (BOO).
Feature Outputs:
Transfer case synchronization clutch.
Transfer case shift motor relays.
Integrated wheel-end (IWE) vacuum solenoid.
Cluster indicators (via CAN communication).
AWD mode (via CAN communication to PCM).
Integrated Wheel End (IWE) System

The integrated wheel end (IWE) system contains the following:

Vacuum reservoir
IWE solenoid
IWEs (spring loaded vacuum hubs)
Vacuum hoses
Check valve
The IWE system uses vacuum hubs that engage the front wheel hubs to the front halfshafts or disengage the front wheel hubs from the front halfshafts.

The IWE solenoid receives engine vacuum from the vacuum reservoir.

When the 4-wheel drive system is in 2WD mode, the 4x4 module (PCM) supplies a ground path to the IWE solenoid to apply vacuum to the integrated wheel ends (disengaging the front hubs from the front halfshafts). In 4WD mode, the 4x4 module (PCM) does not supply the ground path to the IWE solenoid, vacuum is not applied to the integrated wheel ends and an internal spring keeps the front hubs engaged to the front halfshafts.

now this is the principle operation from a ford service manual as I stated before you have plastic hub actuators that you may want to check .

 

[Matthew_B]

Re: Four wheel drive on dry pavement

I thought the same thing as mrfixitman40's

I know someone with a 04 that put a switch in the line to the front hub solenoid valve. It allows him to operate his truck in low range but with 2 wheel drive. With a click of the switch, he can have 4wd on tap.

If you've ever launched a 3000 pound boat while hauling a 4000 lb camper you'd understand why it's nice to have low range when launching.

 

[Waffle]

Re: Four wheel drive on dry pavement

Thanks all for the replies. I have been busier than a one......well really busy

The truck is acting fine and my mind is now somewhat at ease.

 

[mikey.himself]

Re: Four wheel drive on dry pavement

Both my ford pickups are "manual" 4X4 systems (one with electric shift) and its a huge no-no-no to turn on pavement/concrete where the surface has no give like dirt,gravel, etc. You will notice the driveline "pinching" when you turn, and you feel everything overstressing. I see no purpose to drive on the roadways in 4X4 unless its icy or snow. Transmission shops gets alot of blown up transfer cases (planetary gears, drive chain, universal joints)come in because the owners used 4x4 at all the wrong times (makes me want to give those people a bonk on the head. Make a habit to turn it off when you don't need it. Your wasting gas... Jeeps and other Auto 4x4s + awd's do not suffer from this problem though... theyre built to be on all the time.....

you should be ok if the noise is gone....

i use 4x4low at the ramp when pulling my 28' rinker out, don't by any means need to with my f-350 4x4 dually diesel, but i just prefer it as its more gentle on everything and i dont need to pull all that strain on the tranny...

 

[Matthew_B]

Re: Four wheel drive on dry pavement

Transmission shops gets alot of blown up transfer cases (planetary gears, drive chain, universal joints)come in because the owners used 4x4 at all the wrong times

I'll wager that most of the time that is due to boneheads engaging 4WD while the rear wheels are slipping without letting off on the throttle or switching rages at too high a speed and / or in gear.

(makes me want to give those people a bonk on the head.

That's an A YUP

 

[tjl76evinrude]

Re: Four wheel drive on dry pavement

basicly all automakers now have tried to make 4x4 friendly to soccer moms. you can "shift on the fly" up to pretty high speeds and almost NO 4x4's now have traditional hubs. most use a drive flange or any sort of fixed mechanism to where your front CV's/axleshafts are always spinning, thus making it possible to sync the t-case in at higher speeds.

i dont think you hurt your truck. its a ford, its gonna make some squeaks.

i personally love my 4x4 Nissan with manual hubs and actual transfer case with a real shifter, i also run a lockright locker in the rear to make things extra fun. i use 2-lo at the ramps normally just to make it super easy. ive pulled out though with it in 4-hi. it will do it but it takes some clutch abuse since i still have stock gears but i went from 235/75's to 35x12.50's.

 

[mikey.himself]

Re: Four wheel drive on dry pavement

Yup, 2-LO is great at the ramp when pulling it out. My truck basically just idles its way up.

 

[tjl76evinrude]

Re: Four wheel drive on dry pavement

yeah 2-lo is great. ive idled my truck while having full sized tree's dragging behind me. done that a few times when clearing fallen tree's out of trails after storms. i was impressed.

its real fun also on 1 particular ramp i frequent. its a wet ramp with sand all over it so 2-lo + the locked rear + 35" mt's gives a nice howling tire sound if i tap it when towing up. im just clearing a little sand off the ramp though..

 

[Matthew_B]

Re: Four wheel drive on dry pavement

yeah 2-lo is great. ive idled my truck while having full sized tree's dragging behind me. done that a few times when clearing fallen tree's out of trails after storms. i was impressed.

He he, I'm sure your version of a "full size tree" is different than one in the Northwest. Anything short of a dozer doesn't move one of our "full size trees".

 

[tjl76evinrude]

Re: Four wheel drive on dry pavement

yeah i didnt think about that. full sized turkey oaks and sand pines here are twigs compared to some of the really big species out there like your big evergreens.