Max Safe Locked Speed (1 Viewer)

[Beowulf]

>> Hey, that was a textbook example of how to handle <<
>> a misunderstanding by all of you guys. <<

Geez Dougie, and looking back I was just thiiiiiiiiiiiiiis close to hittin' the GDB.

-B-

 

[turbocruiser]

[quote author=Beowulf link=board=2;threadid=12207;start=msg112884#msg112884 date=1078113500]
>> Hey, that was a textbook example of how to handle <<
>> a misunderstanding by all of you guys. <<

Geez Dougie, and looking back I was just thiiiiiiiiiiiiiis close to hittin' the GDB.

-B-
[/quote]

Oh holy crap!!! I was clueless! :-[ I was stupid :-[ I would rather have grenaded my rear differential before I would want you to hit the dreaded button! Please re-accept my apology B , please re-accept my peace pipe, re-accept my offer of , in fact, let me fedex it to ya, yea, let me fedex it overnight, I'll send it chilled, I'll have it delivered by the best beer girls available, I'll keep it coming til you are happy and peaceful and perfect all over again! Really, oh holy crap, I'm freakin out; I did not think it was so serious. I did not think any harm happened at all. I did not think it was worthy of the GDB at all. I'm soooo sorry, crap, what do I do now? :-\ I'm really so sorry man.

 

[Beowulf]

Well, you can send a 24 pack of Boddington's to Beowulf @ PayPal.com if you're truly feeling contrite.

-B-

 

[turbocruiser]

It'll arrive tomorrow! So we're good now right! Whew!

 

[IdahoDoug]

Boddingtons - yum. Where can you get it in a 24 pack though? I only find it in the hyper expensive 4 pack or even individual cans around these parts. Are you joking?

DougM

 

[Eduardo96FZJ80]

Doug,
6 four packs = 24
for all!! and I didn't even see one call for help from the "moderator"

 

[cruiserdan]

[quote author=SteveLCetc link=board=2;threadid=12207;start=msg112882#msg112882 date=1078113079]
Let me ask this another way - is there anything inherently mechanically problematic when running at high speed with the Toyota electric diffs locked? LIke, will they blow up at 80 mph or something? I can't see why there'd be a problem, keeping in mind the torque reduction at speed. I don't understand what the problem might be...
[/quote]

What a hopeless attempt to re-direct a thread

The main issues, as I see them, concerning "locked speed" are the potential for the vehicle to suddenly change direction, or perhaps spin and then go for a roll or breaking something when the "stored energy" of binding components escapes. There is a strong potential to store a lot of energy in "wind-up" and something would have to give. The violence of that "give" would be amplified by higher speeds.


D-

 

[PHAEDRUS]

going way far back to the snow technique question as to weither to stay at high speeds or low speeds it dependso n teh conditions and type of snow. back home 4hi in low gear was the order of the day as the snow is super dry(Utah) so its all about speed to blast through powder. Here in slush land I have found its easier to go very slowly and be in low range and low gear with just a tiny bit of throttle. as soon as the wheels spin back off back up and start again. just my .02 please ignore if you will
Dave

 

[SteveLCetc]

[quote author=cruiserdan link=board=2;threadid=12207;start=msg113116#msg113116 date=1078163361]
What a hopeless attempt to re-direct a thread

The main issues, as I see them, concerning "locked speed" are the potential for the vehicle to suddenly change direction, or perhaps spin and then go for a roll or breaking something when the "stored energy" of binding components escapes. There is a strong potential to store a lot of energy in "wind-up" and something would have to give. The violence of that "give" would be amplified by higher speeds.


D-
[/quote]

Hey D-

I'm thinking that in higher gears the torque is not that great (due to the gearing) so the "potential" is not that great. I had a Pathfinder (don't tell anybody) with an ARB in the rear and it ran fine across the desert at fwy speeds. Tire scrub will unwind any stress - the faster you're going the faster it'll unwind...

By definition the tires are locked together, which works against spinning out.

Steve H

 

[Rich]

You're all making this much too complicated. Whoever at Toyota authored the speed warning firstly no doubt presumed that the vehicle owner had limited or no knowledge of the harmful results of operating locked differentials on hard surfaces. Secondly, as more (center, rear, front) differentials are locked, the steering gets progressively worse. Add these two factors together and you get a warning from Toyota "go slow when you do that!".

 

[IdahoDoug]

Steve,

Axle windup comes not from the torque of the engine (though obviously all forward motion does) but from the need for the tires on each end of a locked axle to turn different rotations when the vehicle's turning. I'm trying to think of why this is so from a physics standpoint, but the effective gear ratio of one tire acting against the other tire is phenomenal - meaning it takes little effort on the vehicle's part to create enormous windup pressure across the axle. I guess it's the ratio. In a shallow turn (such as high speed driving) where one tire SHOULD be turning only .01% slower than the other, the effective gear ratio would be 100:1 - lots of power and the engine will hardly note the load. In a sharp turn, the ratio might be 50:1 which is why you immediately perceive the binding and the engine has more trouble creating windup. Make sense?

DougM

 

[cruiserdan]

[quote author=SteveLCetc link=board=2;threadid=12207;start=msg113527#msg113527 date=1078198311]

By definition the tires are locked together, which works against spinning out.

Steve H

[/quote]

Not exactly. Have you ever cracked the throttle open in a vehicle with a Posi that was on a crowned, icy, road? You get sideways faster than you can think about it. (been there )

 

[cruiserdan]

[quote author=SteveLCetc link=board=2;threadid=12207;start=msg113527#msg113527 date=1078198311]

By definition the tires are locked together, which works against spinning out.

Steve H

[/quote]

Not exactly. Have you ever cracked the throttle open in a vehicle with a Posi that was on a crowned, icy, road? You get sideways faster than you can think about it. (been there )

 

[SteveLCetc]

Yeah, I've done that. How about cruising up a snowy highway in the mountains in 4wd and two no-slips? That's *really* hairy. Selectable lockers are different though. The problem with auto lockers is that when you're pushing you're pushing with the inside tire on a curve (any not absolutely straight line) and when you're pulling you're pulling with the outside tire. That gives a double whammy when you let off the gas in a curve, like to downshift... Actually, with two lockers a quadruple whammy (!!)

I need to put in the center lock switch to try it in an 80...

Steve H

 

[chukarhiker]

I was in some thick mud by Battle Mt. in Jan. that gave me my first good test on my lockers.

I got better traction/more power with just the center/rear locked. When I locked the front and rear I lost power and control which is needed for hauling thru the bad spots.

With just the rear locked I felt like I was driving a tractor and had complete control.

Jim