Friction Modifier- Increase or Decease LSD action?

[OiledMustangGT]

If I want to increase LSD action should I add more or less friction modifier? (it is a clutch type Ford Track-Lock unit)
I think it is less, right?
I dont mind the incresed noise, but dont want to put excessive wear on my LSD.

 

[Michael SR]

quote:

---

Originally posted by OiledMustangGT:
If I want to increase LSD action should I add more or less friction modifier? (it is a clutch type Ford Track-Lock unit)
I think it is less, right?
I dont mind the incresed noise, but dont want to put excessive wear on my LSD.

---

to increase the lsd function, rebuild it with a different plate stack and more preload. when my friends and i used to auto-x those cars, it made a night/day difference.

less modifier means more lockup, but it's not just a groan. you get a popping that rings through the axle shafts. also, from what i remember, less modifier meant quicker wear on the plates.

-michael

 

[metroplex]

That's an interesting question.

Friction Modifier reduces friction.

Ford recommends 8oz or so for its 8.8" limited slip differentials. The rule of thumb is 1/2 of what the manufacturer specs, and slowly add more until you get to a comfortable level.

What do I mean by a comfortable level?

Do you mind a bit more clutch noise? If not, you can opt for more lockup rather than noise reduction.

you want to add SOME FM... but too much and it wears out the clutches. Too little and you can do the same. But if you add 1/2 of what the manuf states and you're comfortable with the noise level... go with it.

I used Redline 80W-140 w/o any FM (it is formulated with FM) in a Dana 60 (9.75") and w/ Traction-Lok and there's no noticeable noise so I never had to add anything.

 

[Michael SR]

quote:

---

Originally posted by metroplex:

Friction Modifier reduces friction.
...
but too much and it wears out the clutches.

---

how does this dichotomy occur?

-michael

 

[MolaKule]

quote:

---

If I want to increase LSD action should I add more or less friction modifier? (it is a clutch type Ford Track-Lock unit)
I think it is less, right?
I dont mind the incresed noise, but dont want to put excessive wear on my LSD.

---

In engine terminology, Friction Modification means "reducing" friction.

As in manual and automatic transmissions, friction modification means adjusting the friction for specific operation.

In the case of LSD's, it means that more friction modifier reduces stick/slip, the locking/unlocking motion or jerking motion of engagement/unengagement. So it's not just reducing friction, it is adjusting dynamic friction Mu to arrive at a particular operational situation.

 

[Michael SR]

quote:

---

Originally posted by MolaKule:
So it's not just reducing friction, it is adjusting dynamic friction Mu to arrive at a particular operational situation.

---

right, i always thought of it as bringing the static and dynamic coefficients closer together. so the transition from one to the other is very smooth.

-michael

 

[OiledMustangGT]

quote:

---

Originally posted by metroplex:
That's an interesting question.

Friction Modifier reduces friction.

Ford recommends 8oz or so for its 8.8" limited slip differentials. The rule of thumb is 1/2 of what the manufacturer specs, and slowly add more until you get to a comfortable level.

What do I mean by a comfortable level?

Do you mind a bit more clutch noise? If not, you can opt for more lockup rather than noise reduction.

you want to add SOME FM... but too much and it wears out the clutches. Too little and you can do the same. But if you add 1/2 of what the manuf states and you're comfortable with the noise level... go with it.

I used Redline 80W-140 w/o any FM (it is formulated with FM) in a Dana 60 (9.75") and w/ Traction-Lok and there's no noticeable noise so I never had to add anything.

---

I'm glad you chimed in. I will be using the RL 80W-140 and I bought some friction mod from ford just incase. I will be adding straight RL, then adding ford FM if necessary