Rear diff lube.
Elder User
Joined: May 2007
Posts: 754
Likes: 1
From: Solon, Ohio
Originally Posted by Mtthwvn73
That's why you have to add friction modifier to a limited slip, because the clutches need the modifier to grab each other, if not, they'd probably just burn up while rubing together and trying to give traction to the wheel that isn't spinning.
Matt
Matt
The friction modifier helps them to slip, not grab.
Hotshot
Joined: Oct 2003
Posts: 17,799
Likes: 103
From: Ashland City, TN
Limited slip and Posi traction are the same thing.
It's just rights to the name. GM is Posi (or dodge, can't remember) and Limited Slip is fords name.
A locker is something totally different. There are true lockers, and slipping lockers.
Manual lockers... Ya you get the point.
I was under the understanding that friction modifier added "friction" which would be more grippyness.
As for anything, your LS rear end only functions while turning and on dirt, or while doing burnouts or playing. So.
I'm still trying to figure out how I bought an LS axle and got a non LS differential.....
It's just rights to the name. GM is Posi (or dodge, can't remember) and Limited Slip is fords name.
A locker is something totally different. There are true lockers, and slipping lockers.
Manual lockers... Ya you get the point.
I was under the understanding that friction modifier added "friction" which would be more grippyness.
As for anything, your LS rear end only functions while turning and on dirt, or while doing burnouts or playing. So.
I'm still trying to figure out how I bought an LS axle and got a non LS differential.....
Ford Parts Specialist
Joined: Nov 2006
Posts: 88,826
Likes: 787
From: Simi Valley, CA
Originally Posted by Talyn
Limited slip and Posi traction are the same thing.
It's just rights to the name. GM is Posi (or dodge, can't remember) and Limited Slip is fords name.
It's just rights to the name. GM is Posi (or dodge, can't remember) and Limited Slip is fords name.
Last edited by NumberDummy; Jul 26, 2007 at 11:38 AM.
Lead Driver
Joined: Nov 2002
Posts: 9,557
Likes: 44
From: Concord, NC
Limited Slip is a type of differential-it's not Ford's name (is TracLoc the term that Ford uses?). Unless the differential is a torque-biasing type such as a gleason torsen, no torque is transferred to the gripping wheel, there is just a resistance to the speed differential between the slipping wheel and the gripping wheel, provided by clutches or thrust loads on gears, or whatever method is used to provide resistance between the two axle shafts.
A non-limited slip differential is an open differential, meaning that the axle shafts are only linked by the spider gears, which provide no resistance to speed differences between the axle shafts.
A non-limited slip differential is an open differential, meaning that the axle shafts are only linked by the spider gears, which provide no resistance to speed differences between the axle shafts.
FTE Legend
Joined: Jun 2006
Posts: 31,930
Likes: 1,499
From: Ottawa, Ontario
Originally Posted by jderry78
so what is a non-limited slip differential? Which is how it is listed on the build sheet for my truck.
FWIW.. there are actual differences between a locker, posi and LS diffs.
-A locker does just what it says, locks both sides of the diff together, both wheels get the same amount of torque regardless of traction.
-A posi transfers torque from a slipping wheel to the other gripping wheel through a complicated gear mechanism. Hence the "positive" part of the name. Some traction on both wheels is needed though, 1 wheel in the air and all TQ goes to that wheel.
-A limited slip just limits the amount of slip between the 2 sides of the diff. The preload on the clutch pack determines how much slip will be allowed. Again some traction is needed for this diff to work. On both the LS and Posi diffs, applying the brakes slightly can produce enough load on the diff to get power to the wheel with traction in some extreme cases.
Ford uses LS diffs in it's trucks. GM uses lockers in most of trucks, though clutch type LS diffs are/were available in some. Very few truck manufacturers ever used actual posi diffs, Toyota and Range Rover were 2 that did.
Last edited by Conanski; Jul 26, 2007 at 11:56 AM.
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New User
Joined: Oct 2005
Posts: 11
Likes: 0
>Your local Ford Dealer has:
>C8AZ-19B546-A .. Friction Modifier Additive
It's probably less expensive to buy it at one of the auto supply stores. I just changed the rear differential in my F250. Two 4 oz. tubes, with the quoted specification, cost about as much as a gallon of the 85W-90 oil. (I have to wonder what the dealer would have charged me for it!) The 85W-90 oil was labeled GL-5 for use with limited slip, and I've read in the past on this forum that the additive is not requited with GL-5 fluid. Don't know if that's true or not, so I put it in anyway. Runs great and QUIETER.
>C8AZ-19B546-A .. Friction Modifier Additive
It's probably less expensive to buy it at one of the auto supply stores. I just changed the rear differential in my F250. Two 4 oz. tubes, with the quoted specification, cost about as much as a gallon of the 85W-90 oil. (I have to wonder what the dealer would have charged me for it!) The 85W-90 oil was labeled GL-5 for use with limited slip, and I've read in the past on this forum that the additive is not requited with GL-5 fluid. Don't know if that's true or not, so I put it in anyway. Runs great and QUIETER.
Senior User
Joined: Feb 2005
Posts: 208
Likes: 1
Just throwing this out there.
http://www.royalpurple.com/prodsa/mgeara.html
http://www.royalpurple.com/prodsa/mgeara.html
All viscosities of Max-Gear are formulated with hypoid friction modifiers necessary for use in clutch or cone type differentials. No additional additives are necessary.
Postmaster
Joined: Oct 2006
Posts: 4,816
Likes: 1
From: Davis & Newcastle, CA
Originally Posted by dickallen
It's probably less expensive to buy it at one of the auto supply stores. I just changed the rear differential in my F250. Two 4 oz. tubes, with the quoted specification, cost about as much as a gallon of the 85W-90 oil. (I have to wonder what the dealer would have charged me for it!) The 85W-90 oil was labeled GL-5 for use with limited slip, and I've read in the past on this forum that the additive is not requited with GL-5 fluid. Don't know if that's true or not, so I put it in anyway. Runs great and QUIETER.
Hotshot
Joined: Oct 2003
Posts: 17,799
Likes: 103
From: Ashland City, TN
Yea, i was always informed to buy oil with the modifier in it already. Makes no mixing mistakes then.
Yes, Trac Loc is one of those jap deals i think.
Or its like the traction controll stuff.
Traction controll uses the breaks to transfer power by slowin down one wheel and letting the differential do the work.
I honestly notice no difference between both my LS rear ends and my open rear end.
*shrugs*
Yes, Trac Loc is one of those jap deals i think.
Or its like the traction controll stuff.
Traction controll uses the breaks to transfer power by slowin down one wheel and letting the differential do the work.
I honestly notice no difference between both my LS rear ends and my open rear end.
*shrugs*