Gear lube and friction modifier

[Fourth Horseman]

Hey all, I'm thinking about switching to synthetic gear lube in both of my cars (both running 4.10:1 ring and pinion gears). I'm assuming I will still need to add the Ford branded friction modifier if using the synthetic gear lube, correct?

[fastblackmerc]

Hey all, I'm thinking about switching to synthetic gear lube in both of my cars (both running 4.10:1 ring and pinion gears). I'm assuming I will still need to add the Ford branded friction modifier if using the synthetic gear lube, correct?

No... using Redline and NO friction modifier for the last 30K+ miles with no problems... noise or otherwise.

[SILVERSURFER03]

i dont think you need it with synthetic oil

[NATEHAWK]

You will need friction modifier if your lube you use does not have it added in. You can get Royal Purple and it comes already added. They stock it at Napa in my area. I just added 4.10's 2 weeks ago. If your lube does not have it get it bottom line.

[Fourth Horseman]

I've got Mobil 1 gear lube waiting to go in, I'll have to see if it includes a friction modifier with it. Anybody know off the top of their head if it does or not?

EDIT: Found that the Mobil1 product does contain friction modifiers (http://www.mobiloil.com/USA-English/MotorOil/Other_Products/Mobil_1_Fully_Synthetic_Gear_L ube_75W-140LS.aspx).

Thanks for the input fellas.

[Stranger in the Black Sedan]

I needed to add 1 bottle of Ford Racing friction modifier in my 30k mile car, w/ 75W-40 Redline or else it chattered very badly cornering. Redline says it has some limited slip additives in it, but obviously not enough for some applications. They say add more additive "if necessary". I would add the modifier. Same thing w/ Mobil 1 75-140, very bad chatter without friction modifier. I guess it will depend on how worn your clutches are. My clutches are so tight that you can feel the drag parking at low speeds, and backing up while turning. For you guys that did not need any modifier, might want to check your breakaway torque to see how worn your clutches are.

[magindat]

No... using Redline and NO friction modifier for the last 30K+ miles with no problems... noise or otherwise.

Ding Ding Ding - Survey said #1 answer!!!

[Fourth Horseman]

Good to know, thanks guys. I'll pick up a couple of bottles of the friction modifier from my Ford dealership just to be safe.