LSD doesnt work/ wrong oil?
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LSD doesnt work/ wrong oil?
hey Folks,
i've got the LSD Diff in my 97' VAN. I know about the LS Additiv, so i bought it for Change.
Before two months i stucked on a puddle of mud which was really tiny. other tire on the street. it wasnt possible to go out, so my self-lock seems to be unable to work.
how does it exactly work? friction-discs?
maybe someone before me Changed the oil without the LSD additiv? what to do then? what to Change?
i've got the LSD Diff in my 97' VAN. I know about the LS Additiv, so i bought it for Change.
Before two months i stucked on a puddle of mud which was really tiny. other tire on the street. it wasnt possible to go out, so my self-lock seems to be unable to work.
how does it exactly work? friction-discs?
maybe someone before me Changed the oil without the LSD additiv? what to do then? what to Change?
Super Moderator
Joined: Aug 2003
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From: Isanti, MN
I don't think an oil change will solve this. Lack of friction modifier can cause grabbing and chattering as you go around a corner because the clutches bite too hard. There are friction discs in the housing that engage when there's a certain wheel speed differential. If they're not working it probably needs to be rebuilt to function again as a limited slip.
FTE Legend
Joined: Jun 2006
Posts: 31,930
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From: Ottawa, Ontario
A factory LSD is setup pretty loose so In order for it to work there has to be some resistance(traction) at both tires, if there is none at all at one tire then these things operate like an open diff. That minimum traction generates a certain amount of preload on the spider gears which engages the clutch packs and drives both tires evenly. These clutch packs wear with age so it's entirely possible your diff needs a rebuild and maybe a tweak to set it up a little tighter than stock so that it can hold more torque and slip less.
Mountain Pass
Joined: Jul 2014
Posts: 160
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From: Germany
Rockauto sells a rep kit: USA STANDARD GEAR USA16007 Positraction Internals; 30 spline axles; Includes Clutches; Forged Rear; RWD; Dana 60; 30 Spline
€413.18
For that money, I'd interchange it for a TrueTrac.
All options avail. here: https://www.ringpinion.com/DiffWizard.aspx
€413.18
For that money, I'd interchange it for a TrueTrac.
All options avail. here: https://www.ringpinion.com/DiffWizard.aspx
Lead Driver
Joined: Mar 2006
Posts: 6,259
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From: IL
If you bought diff fluid that had modifier in it and you added the Ford modifier on top of that, you may have to much modifier in the diff and the clutches won't engage. Even when changing fluid without any built in modifier, you're only suppose to pour 1/2 bottle of FM into the diff, that's 3.5oz and then drive it around to see how it acts, if the clutches are grabby, then add the rest.
Fleet Mechanic
Joined: Oct 2012
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A factory LSD is setup pretty loose so In order for it to work there has to be some resistance(traction) at both tires, if there is none at all at one tire then these things operate like an open diff. That minimum traction generates a certain amount of preload on the spider gears which engages the clutch packs and drives both tires evenly. These clutch packs wear with age so it's entirely possible your diff needs a rebuild and maybe a tweak to set it up a little tighter than stock so that it can hold more torque and slip less.
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So if it is normal for the LSD dosnt working with one wheel without traction, I think the whole function of the LSD is Nonsens. this is the Situation while I Need the function 
did a lil bornout-start, felt the rear slipping to the right while the tires turn. tells me that the LSD is working, but just with traction?
did a lil bornout-start, felt the rear slipping to the right while the tires turn. tells me that the LSD is working, but just with traction?
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Super Moderator
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From: Isanti, MN
Found this video about the subject, it's pretty well done and worth a look:
Logistics Pro
Joined: Jul 2006
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From: Detroit
You can gently apply the brakes or better yet the parking brake to simulate traction on the slipping wheel and improve the limited slip action. Modern cars with traction control can apply a brake on the slipping wheel independently and control throttle to make this happen. I test drove a Sprinter in 2003 before I bought my Ford E150 and put one wheel on ice, the other on pavement, gave it full throttle, and it gently accelerated without wheel slip.
I had put an Eaton posi in my Ford van and it worked great but did chatter a bit around turns on wet pavement--which told me it was working. I never once stuck the van in 13 years and 129k miles. Using LESS LSD additive will increase chatter but in theory improve LSD function.
You can do some google searching on "using brakes to improve LSD" and find more theory on that concept.
George
I had put an Eaton posi in my Ford van and it worked great but did chatter a bit around turns on wet pavement--which told me it was working. I never once stuck the van in 13 years and 129k miles. Using LESS LSD additive will increase chatter but in theory improve LSD function.
You can do some google searching on "using brakes to improve LSD" and find more theory on that concept.
George
Logistics Pro
Joined: Jul 2006
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From: Detroit
Adding too much LSD lubricant WILL reduce the effectiveness of a friction clutch based LSD unit. Noise is not the issue. You can use a gear lube like Mobil 1 (which has LSD additive) in an open differential with no problems because it will not have an effect on an open differential. However, you CANNOT use Mobil 1 gear lube in a manual transmission (like the one in my Subaru) because it will let the sychronizers (which are cone clutches) slip and gears will grind. I found that Delvac truck gear lube does not have LSD additive and it has been in my Subaru transmission for the last 80k miles. LSD additive is a FRICTION modifier. So if your gear lube already has LSD additive, adding more will probably make the LSD less effective.
George
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