Max speed in 4WD??

[Ali]

Hi all

What is the maximum speed the Pinz can go when engaging
the front axle drive (4WD) without causing any problem to the drivetrain??

How long is the distance i can drive it using 4WD??

[Jimm391730]

Sorry for the double post!

[Jimm391730]

What is the maximum speed the Pinz can go when engaging the front axle drive (4WD) without causing any problem to the drivetrain??

Any speed, as long as you are traveling in a straight line, and preferrably while coasting or close to it. It doesn't matter how fast the shafts are spinning when you engage but the relatvive speeds of the shafts need to be very close during engagement. Turning sharply makes the front axle travel further than the rear, therefore it turns faster. Of course the faster you are traveling, the more likely any turns will be bigger. A lot of torque on the rear axle will likewise make it turn faster than the coasting front axle due to the "slip" of the tire tread as it flexes.

How long is the distance i can drive it using 4WD??

Off road, where the traction surfaces are loose and can allow the tires to slip, you can drive indefinitely. On road (such as icy and snowy conditions) likewise, but beware of bare patches of pavement that can damage the drive train if you are turning. Going straight is never a problem but my rule of thumb is that on dry pavement anything more than 1/2 of a turn of the steering wheel away from straigh ahead is a problem. Most tires have close to 1% slip on the driving wheels just pushing the vehicle down the highway (this is normal and expected torque). If we allow an addtional 1% of "push" from the other axle then the drivetrain can safely accomodate a 2% difference in speed between the axles with just normal tire tread flex. In a large diameter turn (like half a turn of the steering wheel) the front axle only goes in a few inches larger circle than the rear axle while the radius of the turn is 100 feet or so; hence the 2% limit is about here.

Obviously the Pinz drivetrain is designed for much, much higher torques when in low gear, low range, so brief encounters with pavement while turning in 4WD can be usually handled safely (especially if the truck is not heavily loaded). However, it is not recommended.

[Bruce Berger]

When my 4X4 slave cylinder was sticking I had to drive my 710 about 50 miles home on mixed freeway and surface streets. It survived OK. I'm sure there are people out there with similar "war" stories. It goes to show the robustness of the Pinzgauer design but it certainly isn't something I'd recommend doing. It is very hard on the tires.

We won't talk about the time I had to drive someone else's Pinzgauer about 10 miles on mixed surface streets and freeway with the front locker stuck engaged. Once again, it survived but certainly not recommended.

[Ali]

Many thanks Jim & Bruce