Should I put friction modifier in Red Line 75W90 gear lube?

[maverick0716]

I bought some Red Line synthetic gear lube today and it says it has friction modifier already in it, but the guy at the store said that he had it in his camaro and he need the FM. So I bought some anyway, just to be safe. My question is can anything go wrong from putting too much in?....if it already had some in it?

 

[HISSIN50]

should be fine.

 

[DropTopR]

But don't overfill the diff tho.

 

[ratrapp]

i never trust it when they say modifier already added.i always add "skunk oil"to my diff. anyway and it gives me a piece of mind.

 

[evn_05]

If it is a synthetic lube then you do not need the "skunk lube" at all. Haha skunk lube I love that, and it is so true that stuff reeks to no extent.

 

[jwcma]

The Red Line friction modifier doesn't smell half bad, compared to what originally came with the car.

 

[Mustang5L5]

I never did. I just put the bottle straight in and never added any. Worked fine for 40,000 miles until i refilled it again with Mobil 1 and added the stuff myself.

Too little friction modifier and you get rear end chatter around corners. Too Much and your trac-lok is useless and you'll spin 1 tire and barely spin the other.

 

[ratrapp]

not always.i worked in a chrysler dealership for about 5 years and about 2 or 3 years ago there was a problem with limited slips being jerky and noisy.the problem was not enough modifier.the solution was to add 2 or 3 small bottles of modifier to the unit and it fixed probably 90% of the ones i worked on.i do agree that too much would hurt it but that would take an awful lot of modifier to do that.

 

[HISSIN50]

im not sure that one can compare apples and oranges (Mopar vs Ford).

some guys run with no modifier and run fluid for an open diff so that the clutches lock up as tight as possible (autocrossing, etc) - but at the expense of clutch life and some groaning.

im thinking it might depend how tight the clutches are packed. if someone really packed them (added another plate, etc), more modifier may be needed, as Ratrapp eluded to.

 

[ratrapp]

not sure about fords but i can verify that you use the same modifier for mopars and gm,i'm pretty sure for the average limited slip unit they're all the same.we're not talking about ones like moroso diffs. or ones like that.

 

[HISSIN50]

not sure about fords but i can verify that you use the same modifier for mopars and gm,i'm pretty sure for the average limited slip unit they're all the same.we're not talking about ones like moroso diffs. or ones like that.

ok, i see the confusion. i always thought that the various manufacturers LSD's were differnt in design. like i think posi's use a ratcheting deal. ours are clutches.....and so on. that is why i said that it was apples to oranges.

i could be wrong.

 

[89MustangGX]

If it's already included you don't need to add.

You do need to refer to the bottles, as other synthetics like Mobil-1 don't have it and need it added, while some like yours already do.

 

[cleanLX]

If it's already included you don't need to add.

You do need to refer to the bottles, as other synthetics like Mobil-1 don't have it and need it added, while some like yours already do.

I've got Redline in my diff, revised stacking order and extra clutch in the t-lok.
No problems.
Locks up at the track, and does not chatter on the street... although it does chirp the inside wheel if on the power a little and turning rather tight...