What is the maximum speed (if there is one) I can go while in 4x4 HI and LO?This morning we had some snow on the roads and the hwys. had yet to be plowed. I put my 2000 xlt 4x4 in HI and noticed that when I get to about 40mph it starts to whine. Needless to say I quickly put it back into 2wd. So that got me thinking, can I not go faster than 40mph while in 4x4 HI. I'm thinking that the fastest I can go in 4x4 LO is myabe 10-15mph???

 

I have never driven in 4x4 HI but I am pretty sure you can go faster than 40.

 

You think I need to have my transfer case serviced?

 

45 mph top speed in 4 hi. any faster and you'll start to cause internal damage to the transfer case. i believe it states this in your owners manual.

 

Why would you want to go that fast? There is a reason that you need 4wd maybe try to slow down and maybe save a life or two.

 

Mine says I can SHIFT into 4Hi at any speed up to 50 mph. I see no need to drive much faster than that in 4Hi, but I have for short periods on a snow-covered interstate. In 4Lo, I drive by the tachometer but I have gone 35 mph in 5th on the beach for quite some distance, easily 20-30 minutes.

You should certainly check the Txfr case oil level (while you're there, might as well drain and refill it - I use synthetic ATF). The Explorer I bought was dry except for some black sludge and aluminum shavings from the belt slapping the case (I took it apart). It was a BW4405, but similar enough.

 

they say 55mph in 4hi

i dont know if your 2000 has PVH or Live Axle but in a live axle configuration you can go any speed in 4hi

 

i stand corrected. its been awhile since i read the manual.lol i thought live axle was where you had to monitor your 4 hi speed?

 

if you have a live axle and are running 90mph your front drivetrain is spinning 90mph in 2wd, so whats the difference?

I have tested it and it will go in and out of 4wd hi at 90mph on a dry road. No clunk nothing different than when going 30mph.

 

I believe that 98-00 are live axle and can drive at any speed in 4 hi. but I wouldn't be doing 90 on an ice covered road. I drove 55 last night in 4 hi and nothing seemed out of normal.

 

I don't go any faster then 30 in 4lo, no faster than 50 in 4high.

 

didnt think about that.. you da man beard.

 

Relax, I'm just inquiring about the 4x4 system. I appreciate your concerns though.

 

98-00.5 are PVH not live axle.

 

55 in 4hi all the way to work this mornin.

light traffic and straight roads

i didn't have any tx case whining, btw

 

+1 on PVH!


...because you can make them locking hubs easier

 

As for low-range, I thnk you'll max out the RPM before you can reach a maximum speed. It is geared so low, you couldn't go too fast if you tried.

 

PERSONALLY I have NEVER seen it written down by Ford about how FAST you can drive while engaged in 4x4 high!!! BUT I have seen it written down by Ford in the manuals about how fast you can be going ( WHEN YOU FLIP THE SWITCH TO GET INTO 4X4 HIGH)

An example would be my truck you can safely flip the switch into 4x4 high at speeds UP TO either 45 or 55 mph, I can't remember exactly what speed the manual clearly says at the moment because my manual is packed away and I aint going to go look for it.

 

I just checked my manual...2009. The only speed limits that are mentioned are for the shift points. No where does it mention top speed in 2hi, 4x4hi/4x4lo. If someone needs the shift points pm me and I'll see what I can do for you.

 

So it's safe to say that I shouldn't have a whine at about 40mph. What could the whining be? BTW the oil in the transfer case was just recently topped off and no known leaks to speak of

 

Yes

 

i drove to work this morning going 55 in 4hi, ive been offroad and doing 55 in 4lo, you will max the rpm before anything else in 4lo

 

so which years are live axle?

 

So 00.5 and up.

 

k b/c i was doing like 55-60 on a trip to ohio in 4x4 high and had no problems and i was driving for like 22 hours.....