[Bacchus]

Hi all, I have a 2005 CRD 4WD, and I'm wondering is there a speed limit to engage the Full time 4X4 and dose it disengage it self at a specific speed (say 100km/h). I know that the part time 4X4 is good up to 80Km/h and only on slippery surfaces at low speed.

Sincerely, a proud JEEP owner

[jeepjeepster]

The OM says to shift at speeds under 55mph but once youre in 4wd there is not limit. Ive done 75-80mph in fulltime with no problems.

Just remember that being in 4wd does not mean you can drive faster.

[naturist]

Your owner's manual should state the max speed for changing any of the transfer case settings (ie, from 2 Hi to 4 full OR 4 full to 2 Hi) is 90 km/hr. You don't want to go that fast in either of the part-time drives, but there is no problem associated with going faster in 4-full. And no, none of them will disengage themselves regardless of how fast you go.

[Jeepman56]

Originally Posted by naturist

You don't want to go that fast in either of the part-time drives...

Really? Just curious to where you have heard that. I thought that if the appropriate road conditions were present you could drive highway speeds in Part-Time. Maybe I am mistaken.

[Bgeddes]

I thought that if the appropriate road conditions were present you could drive highway speeds in Part-Time.

If roads are that bad, no way can you do highway speeds with sense.

[CharBroiled]

part time 4 is for slippery/loose surfaces ONLY and you would have to be crazy to do highway speeds if its slippery. 1st time you tried a curve the tires would slip and youd be in a ditch.

thats what fulltime is for..

[naturist]

Originally Posted by Jeepman56

Really? Just curious to where you have heard that. I thought that if the appropriate road conditions were present you could drive highway speeds in Part-Time. Maybe I am mistaken.

I understand that sports car european rally freaks drive as fast as 100 mph on logging roads (loose gravel, at best). If YOU are that crazy, feel free to try it.

Part time 4 wheel drive absolutely requires that the surface be slippery enough for one or another wheel to pop loose just for a second from time to time to make up for the fact that the two axles MUST spin at the same rate. If the surface isn't that slick, things will break instead. I don't know about you, but while I MIGHT be willing to attempt highway speeds out in the middle of a frozen lake where there is nothing to slid into for miles, on a road somewhere with trees and ditches and stuff, I stick to slower speeds, thank you very much.

[katiesdad7]

Do you notice that when you are using fulltime 4x4 the driveline still binds up? I use it here in FL during heavy rains and it hard to park because the drive line binds up.

Is this normal?

[grogie]

If you have Command-Trac, you can shift into 4WD at up to 55 mph, and 4WD part-time or four-low should only be used on slippery roads (snow, dirt, etc.). Do not use 4WD on any hard/ dry road surfaces.

If you have Selec-Trac, using 4WD full-time, you can run at any speed as long as road conditions are safe (but only shift into it under 55 mph). My wife and I use full-time in our KJ on the highway often at over 55 mph (such as when it's raining or for mixed road conditions). A Jeep Engineer in the recent '08 Liberty Q&A specifically stated this.

[grogie]

Originally Posted by katiesdad7

Do you notice that when you are using fulltime 4x4 the driveline still binds up? I use it here in FL during heavy rains and it hard to park because the drive line binds up.

Is this normal?

Are you actually getting that transfer case bang like if you had it in part-time and took several hard left turns on dry pavement (my wife did this before I explained to her when not to use part-time!), or are you just feeling it in the steering (like the front wheels are slipping some)? I have felt it some in the steering with full-time, but I've never had the bang that my wife got.

[CMax26az]

Originally Posted by katiesdad7

Do you notice that when you are using fulltime 4x4 the driveline still binds up? I use it here in FL during heavy rains and it hard to park because the drive line binds up.

Is this normal?

Even in FULL TIME 4x4 some driveline binding at low speed, sharp truns is to be expected, especially in reverse and turning as if backing into a parking space.

Keyword: SOME, if its excessive you may need to have the system checked to make sure its not sticking in PART TIME, but the difference between how the 2 systems act on pavement is OBVIOUS.

[JoBo]

I've found that when shifting out of full time 4 to 2 wheel hi if I don't leave it in 4 part time for a short distance before going to 2 hi it will remain in 4 part time and I get the resulting bind. The lights are both off and even driving a mile on city streets and pulling to my garage it's still in part time. The next time I drive it, it's still in part time. A few feet in the part time position then to 2 and all is good. I'm told to "bump" it and it will shift out of it but with the CDR and the auto trans it don't "bump" I've learned how to avoid it but if the wife ever did it it would be behind a tow truck

[grogie]

Originally Posted by JoBo

I've found that when shifting out of full time 4 to 2 wheel hi if I don't leave it in 4 part time for a short distance before going to 2 hi it will remain in 4 part time and I get the resulting bind. The lights are both off and even driving a mile on city streets and pulling to my garage it's still in part time. The next time I drive it, it's still in part time. A few feet in the part time position then to 2 and all is good. I'm told to "bump" it and it will shift out of it but with the CDR and the auto trans it don't "bump" I've learned how to avoid it but if the wife ever did it it would be behind a tow truck

I know what you mean about the wife . You ought to have your dealer look at it. Ours just goes back into 2WD by letting up on the gas and then hitting the gas again.