So now you're saying the front OPEN diff is just as good as a locker too!?!? LOL

I wonder why they even make lockers then? I also wonder why lockers are highly recommended and/or mandatory on the harder trails in Moab?

 

I would agree with cquestad's statement IF these trucks had 4 channel ABS....

 

So you don't have to use you brakes...

Your not getting my poke...I am not saying...again I am NOT saying there are not uses for a locker that they are not better than a LSD in those situations.

I guess we should all just be driving around on pavement 90% of the time with Detroits front and rear with our school bus wheel bases and monster powerplants. Our tires, axles, ujoints, handleing on ice, and overall driver and passenger comfort would appreciate it!

We are talking about "in a pinch use"...what LSD are really designed for. Not hard core crawling. I still stand by my comments.

I have driven a 91 F350 reg cab long box with 37's and LSD rear through ALMOST everything Moab has to offer...thanks to my brake pedal.

This whole post is about the OEM LSD...which works great assuming it is actualling in the axle and used properly....not whether true lockers out perform LSD's in a rock crawler. wow....

 

I don't recall the ABS functioning at all at low speeds in our trucks...so I am not sure why you think that matters either.

I appologize for sounding aggressive...but the posts stating the LSD does not work are killing me. Maybe a few of the LSD's out there...or the fact that one may not actually be in the axle...or user error cause a few to not work as expected, but MOST are working fine.

Suggestions have been offered to help and try remedy the problem...and it has turned into a edited by admin instead.

I guess since a couple of Cummins have blown up or not performed as expected...so ALL of our Cummins are duds?????? LOL

 

Well, MY Cummins hasn't blown up yet... but it's not like I haven't been trying!

 

It seems like the guys having trouble have trucks that are 04.5 and newer. It makes me wonder if DC swithched to a cheaper l/s setup. My 03 has always worked as it should. Even when I got stuck at the farm with the fiver, it was spinning all 4 tires. My 01 also works great.

 

All four tires can spin.....but not at the same time unless ya got a lsd front diff also. Today I was trying to back the dually up the small icey hill to my parking spot at home.....both sides were spinning ... but not at the same time as my rear diff is open. I put on the parking brake sometimes I can get the other tire to spin other than initial one but only one will spin. ks

 

from what ive experianced at work, every person that complaned about the factory unit not working had 1 of 2 problems....
1. absolutly no resistance alowing the other side to free wheel. when tested an even the slightest resistance was placed on ti, bingo.. worked perfect...
2. cover was pulled only to find an open case...


the only time i have goten only 1 tire to spin was durring the recent snow stoms we had here in the pnw. i purposely parked with both tires on a sheet of wet ice and the front tires agenst a curb. i let the clutch out froman idle a couple times to get the tires wet the let them come to a stop.. (slick enough they continued to spin w/ the clutch in...) then i let the clutch back out.. got out of the truck and had one spinning.. the resistance from my boot agenst the trad was enough to get both spinning...

case closed in my mind..

 

Ahhhh yes, the gold 'ole Fallocy of Misleading Vividness-an American favorite-and something that drives Philosophers INSANE!!!

I am so glad you do not fall victim to it!

 

Wow...talk about blowing stuff out of proportion.

It's pretty simple. First you said the LSD is as good as a locker, then you said the open front diff is as good as a locker. Both statements are simply false, and that is all I was saying.

A Limited Slip Differential does just that...it LIMITS the SLIP. It does not eliminate it. Now, if there's some slip happening then I think we can come to the conclusion that all 4 tires are not always going to spin at the same speed. Simple physics really.

 

Easy now!

"All 4 tires are not always going to spin at the same speed" is true regardless of anything else, for they all 4 NEVER spin at the same speed since no two things can logically do that.

I think what you meant to say was, "If there is some slipping, then we can conclude that at that moment, all 4 tires are not spinning at relatively the same speed."

However, that too, is not NECESSARILY true. It may be the case, but it does not entail it to be the case (i.e., make it logically necessisary) for you could imagine a world such that there was the same amount of slippage on all of the wheels and that even though there was slippage, (since it was the same amount on all 4) all 4 wheels were spinning at relatively the same speed.

Sorry for being a pain in the backside. It's the philosopher in me!
I will now!

 

Re-read what I wrote...ahhhhh.

I said WITH the brake pedal, I can FORCE all 4 tires to spin the same speed.

I did not say by themselves.

It is really simple...so I guess I will have to make a "scientific" explanation.

Lets say a rig is crossed up in a ditch...left front and right rear touching...the other two in the air. To move the vehicle, it would take x amount of torque (taking into account elevation change, friction, etc.) applied to the two wheels.

If the diffs were open, the two wheels in the air would spin. If the diffs had LSD...the may or may not spin.

With either diff, if a "brake torque" greater than the required torque to move the vehicle is applied, then a drive (or engine) torque is applied greater than the resisting brake torque, viola...you have 4 tires turning the same speed. PERIOD.

Maybe that is too complicated for you to understand. Like I said...lockers save your brakes and prevent having to waste torque (brake torque) to achieve true 4 wheel drive.

 

QUOTE=gus's 03;1318695]from what ive experianced at work, every person that complaned about the factory unit not working had 1 of 2 [ problems....
1. absolutly no resistance alowing the other side to free wheel. when tested an even the slightest resistance was placed on ti, bingo.. worked perfect...
2. cover was pulled only to find an open case...


the only time i have goten only 1 tire to spin was durring the recent snow stoms we had here in the pnw. i purposely parked with both tires on a sheet of wet ice and the front tires agenst a curb. i let the clutch out froman idle a couple times to get the tires wet the let them come to a stop.. (slick enough they continued to spin w/ the clutch in...) then i let the clutch back out.. got out of the truck and had one spinning.. the resistance from my boot agenst the trad was enough to get both spinning...

case closed in my mind..[/QUOTE]

I don't understand what case is closed. Your description is of an open diff. The LS diff tries to spin both tires by biasing the torque coming in from the driveline. Your example equals the "traction" by adding resistance to the spinning tire until it equals the non spinning tire. In this case both tires are equal and will spin equally with an open diff. Remember, an open diff always delivers equal torque to both tires, spinning or not. So if you add traction or resistance to the spinning tire until it equals the non spinning tire, they will both spin. A locked diff always delivers equal speed to both wheels, but almost never equal torque. A LS is somewhere in between depending on the conditions and the design.


Wetspirit

 

Hey 53Willys, I am curious what you will find out when ya' pull the cover. It is strange how another user in this thread said his truck came with that option but he had an open carrier in there.

 

53Willys,

It really sounds like you have an open diff. Maybe the best thing would be to go to the dealer and tell them you can't make it work, and to get your fluid changed there. Then when they open it up and find it missing, you can point out that it is on the sticker and you paid for it. They won't believe you unless they look in there anyway and it would be best for them to "discover" it.