Inadvertant use of 4wd low....

[dkryan]

My former neighbor called and said she had inadvertently hit the "4-WD low" switch on her 1996 Explorer. The dashlights were not working when she did this.

She said she drove no more than 1/4 of a mile at speeds of 0- 30 mph before she realized what had occurred.

Now she's hearing a "clunking" noise on occasion from the rear-end. She thought she'd hosed up the tranny, but I told her that it was likely any damage would be to the diffs and/or transfer case, not the tranny.

What advice would you guys give at this point? Change the diff and tranny fluids out and hope for the best? I told her confirming any major diff damage would entail removing the diff housing and checking the hard parts.

I've already provided advice about fixing the dashlights.

 

[Scienceman]

ford (especially in the 90's) had sucky dashboad lights.

 

[FusilliJerry82]

Pretty much what you said with the fluids. However IIRC you had to be stopped in park for 4 Low to even engage even if switched to it, so theres a chance it wasn't even engaged. Also I seem to remember the manual saying "stay under 30" in low, so if she indeed was, it should be OK.

 

[PT1]

I would examine the u-joints on the driveshafts first. She could have spun one of the needle bearings with the torque down when it dropped into low. I really doubt she would have fried the tcase or diffs in 1/4 mile.

 

[BeanCounter]

Not doubting that it wasn't 4L, but is she sure.
I honestly don't know how fast you can get up to in most vehicles in 4L, and by the time you are going through 1st and 2nd I'd imagine you'd figure it out.

Anyway you can check on these noises to verify?
I really don't think you would be grenade-ing the trans or diff's doing this, other than possibly the front diff and corresponding drivetrain parts (if the F & R gear ratios are different especially).

 

[tmorris1]

I bet it never went into 4 Low. My Ford won't let you unless you are stopped in Neutral.

 

[HWEaton]

Originally Posted By: tmorris1
I bet it never went into 4 Low. My Ford won't let you unless you are stopped in Neutral.


Exactly. Even if you are rolling down the road already in 4H and place the selector knob on 4L it will not shift into 4L.

 

[BeanCounter]

Originally Posted By: HWEaton
Originally Posted By: tmorris1
I bet it never went into 4 Low. My Ford won't let you unless you are stopped in Neutral.


Exactly. Even if you are rolling down the road already in 4H and place the selector knob on 4L it will not shift into 4L.


Yep, my plays the blinking game under it times out or you stop and get it in the correct gear. I think you'd be hard-pressed to find an electric shift car nowadays that would let you shift to 4L on the fly.

 

[01rangerxl]

My 1995 Explorer wouldn't just shift into 4 low without some conscious effort on my part. It had to be in neutral, and you could hear and feel it engage. Just because the switch on the dash went to the 4 low position does not mean the shift motor actually shifted to 4 low. My guess is it stayed in 2WD or 4 auto.

I drove my Explorer in 4 low on pavement once when I was trying to track down one of its many noises. Believe me, there's no way she would have made it to 30 MPH or even 1/4 of a mile down the road without knowing something was up right away, so I'm betting it never actually engaged.

 

[FL_Rob]

If there was a way to physically shift(not electric)into 4low, it sure wouldnt be the axles to worry about ,it would be the transfer case, tranny and redlining the engine.The effect of that compression braking would be like slamming on the brakes .Did any of this calamity happen?If not, dont worry.I hope..

 

[dkryan]

Thanks for the responses, gentlemen.

Supposedly, she did this while stopped (in park) at a gas station last evening. Hence not being able to see that she had hit the switch to 4-wheel low.

She said she felt something was wrong in the back-end based on the way it sounded and the way it drove. So it's possible it did go into "low" from a parked position.

I was just uncertain how much grenading would occur at less than 30 mph for about 1/4 mile.

And with 130k miles and 14 years on that ride, if it's not the diffs or tranny, then eventually it would be something else!

 

[Trav]

The Borg Warner electronic transfer case should not go into 4 low if its not in neutral and brake pedal depressed.I have seen some that will go while in park but never in drive.It would be a serious safety concern if it did.

 

[JHZR2]

Originally Posted By: BeanCounter
Not doubting that it wasn't 4L, but is she sure.
I honestly don't know how fast you can get up to in most vehicles in 4L, and by the time you are going through 1st and 2nd I'd imagine you'd figure it out.


+1

 

[MonumentOiler]

If she was parked and then drove it 1/4 mile at up to 30 mph in low I can't see how it would cause damage. It should be designed to operate in Low.

I would just troubleshoot the noise and disregard the 4L incident.

Maybe she just wanted you to have a reason to come over.