torsen warranty

[--weezl--]

so i've got the 31 spline torsen in my 07, with like 5000miles left on the warranty, i've been noticing a lot recently one tire spinning only, i did the brakes today, and noticed that if it's in gear, and the back end is jacked up, i can spin one tire, and the other tire spins the opposite way, if the transmission is in neutral, the drive shaft turns, and the opposite wheel stays still... the torsen is obviously not working, do you guys figure this is covered by the powertrain warranty?

 

[satan]

Are you certain about your diagnosis?

Torsen design is based on torque division by a fixed ratio - available input torque is divided across the loaded axles inversely by rotational resistance (an individual axle/wheel's resistance to spin) so that the slower spinning wheel is provided more torque...

If you have one wheel spinning for the given input - there is zero resistance on that spinning axle - the Torsen unit would be trying to divide the available torque by zero to apply its torque bias ratio... on a torsen (series 1) a spinning wheel is a spinning wheel, since there's on endemic resistance to rotation - required side-thrust frictions are not developed in the differnetial...

The Torsen 2R axles have a built-in 'resistance' to combat this situation - My understanding (Fully needs some validation, as it's been some time since I was schooled on this) is that the FX-4 level 2 Ranger uses a T2 but not the T2R (with the included resistance to fight free-wheel spin).

Section 3 of this paper (PDF) discusses this kind of operation (section 4 has the supporting math, if you're interested - illustrating the free-wheel spin potential), but it'd be good to hear if the behavior that you're seeing is shared by others with an FX4-2 of similar vintage...

 

[--weezl--]

i started reading up about it last night and saw how it didn't have clutches and such, which is a little surprising, because my truck still calls for a bottle of friction modifier to go in with the fluid. there is talk of double pedaling being in the owners manual for the H1, stating you can apply the needed resistance to do the torque transfer by stepping on the brakes, i'm going to see if i can find an empty parking lot that will let me try this out... but in order to do that, i'm going to need to get one tire spinning

 

[satan]

I find the Torsen design reacts well to the e-brake...

Since braking is normally heavily biased toward the front, you'll gain a bit more "action" with an e-brake application. If you find yourself with one-wheel up alot, maybe adding a length of tube onto the release lever for the e-brake would help ya (to prop-out the release handle forcing the brake to become another pedal -- Much like taping in the thumb-buton on a console e-brake)

I'm not sure what the bia ratio for the Ranger' Torsen axles would be, but I'm thinking at or above the 3:1 point, so you'd end-up "out-pulling" the ebrake by 3:1 or better... Not too shabby !

 

[--weezl--]

i should have updated this thread a while ago, i was looking over all of my old threads to get a timeline for a few things...

anyways, the torsen WAS defective, and the dealership thought it was weird because apparently they work, or they blow up (99% of the time) and it was replaced as per the warranty, i BELIEVE i read on torsen's website that the one in the ranger is a 4:1 bias, with "no" friction or resistance in it...

with my new one, i had the back end jacked up, fixing my rear brakes (apparently i didn't assemble one of them the last time i did it [above])

when i spin the tires (slowly) in neutral, the other tire turns the same direction, like a clutch based limited slip, and the drive shaft turns also, however if i turn it hard, or fast, it breaks "traction" in the diff and the other wheel turns backwards, and the driveshaft stops turning, additionally, the torsen IS now working

i might try that tubing trick, though i find most of the time i'm needing the torsen to lock up for me, is a situation where i need to be nice and slow while going over the crest of something, and is involving riding the clutch a little bit... which requires my left foot to be on the clutch, and can't 3 pedal it... though i will start trying to set the ebrake a few "clicks" (even though my pedal doesn't actually click)

 

[cstishenko]

Thanks for bringing this up. i believe that i am having the same issue in my 07. How did you go about asking the dealer about it?

 

[--weezl--]

I want in and said "MY DIFF ISN'T WORKING, FIX IT YOU DOUCHES!"

To which they replied "yes it is sir, if you can drive it isn't broken" then I said "fawk!!!!'"


Then I went to another dealership, told them it wasn't working, got into an argument with the service advisor, asked for the manager, the manager came out and basically said "torsens dont wear out, the diff either l/s's or blows up... So I said it's still not right, we discussed the possibility that it was an open diff, I showed him the window sticker, which says torsen, then he said ok, we will test it as per the service manual, I got a phone call back about 3 hours later saying they had a new diff on order from a city about 4 hours away, (edmonton) and it would be here the following day

Best way to test it, go find an icy patch, put it in 2h, spin the tires, if you get both going, it's probably fine... Then try 1 tire on snow, one on ice, try it, the one on snow should be spinning, or both spinning, if the ice one is spinning, apply the ebrake, lightly, while spinning (no foot brake) if they both start spinning, it's good...

 

[cstishenko]

I will go try this today. i feel as though mine is not working properly. i will report back.

The both wheels off the ground test should be... in neutral in the air both spin forward. at a greater speed or force of rotation one will spin backwards?

 

[--weezl--]

what? no, in the air, the rear diff acts like an open for the most part... my old one acted IDENTICAL to an open diff, the new one, if i SLOWLY start spinning one, the other spins the same way, as soon as i start putting umph into it, the other tire reverses direction, but everything i've read online has told me that the back end in the air test is not reliable on torsens because it is not a "limited slip" diff, it is a torque sensing or torque bias differential

 

[cstishenko]

I got ya.

I went out and did the ice and dirt test. It works. But not very well.

I had to apply SO MUCH ebrake that the engine could almost not overcome.

Now is it possible that they wear out, and become less effective?

 

[--weezl--]

not really... i would take it into the dealership and get them to test it, do it while getting an oil change or something, less of a chance they charge you to test it (if there's nothing wrong)

i had one dealership charge me 70$ because they couldn't find my transmission problem (which was covered by the warranty and fixed a week later) and another charge me nothing for an oil change, diff replace and transmission job (oil change was only thing out of warranty and it took 2 hours)

 

[cstishenko]

Alright. i broke a front cv shaft last time out... i'll get it fixed up and see what they say. i also emailed torsen with my findings to see what they say before i walk into the dealer without ammo of any kind.

 

[--weezl--]

it's not really an ammo needed issue, you've got a part under warranty, 99% of all dealerships will jump for joy at warranty work, the dealership i got my truck from gave me free parts on all of my oil changes for 4 years as long as i get all my warranty work done there...

 

[cstishenko]

After speaking with Torsen, my differential is functioning properly.

They never intended our factory supplied diffs to work in the manner that we are hoping they do. The Torsen 2.2 commonly wears and becomes more of a 2.0:1.

The guy I talked to at Torsen basically said, one tire on ice one on dirt, best of luck bubs. You'll have to use your e-brake, and even then goodluck getting off the ice.

Ford really ****ed up, and should have put the Eaton locker in that GM used as it works SO DAMN WELL.

Shoot me your e-mail address via PM, and i'll forward it to you.

 

[Gotta_gofast]

I don't wish anyone the plague of the GM grenade80... I think Toyota has the best idea of offering a factory electronic locking differential.