Limited Slip Fix
Lead Driver
Joined: May 2003
Posts: 9,303
Likes: 48
From: Lyndonville, Vermont
Many LS'S from ford are not set up correctly from the factory. If he doesn't have chatter without modifier he needs to take it in and have it torque tested to see whats up. The dealer may rebuild or replace his diff.
Dick
Dick
Senior User
Joined: Oct 2004
Posts: 420
Likes: 0
Originally Posted by 99f350sd
Many LS'S from ford are not set up correctly from the factory. If he doesn't have chatter without modifier he needs to take it in and have it torque tested to see whats up. The dealer may rebuild or replace his diff.
Dick
Dick
OR...he could put in the proper amount of Friction modifier that the book calls!!
as I said...you dont want to take it to the dealer for waranty w/o the FM in it!!
Thread Starter
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Senior User
Joined: Jun 2003
Posts: 100
Likes: 0
Originally Posted by 99f350sd
Many LS'S from ford are not set up correctly from the factory. If he doesn't have chatter without modifier he needs to take it in and have it torque tested to see whats up. The dealer may rebuild or replace his diff.
Dick
Dick
Thanks for all the input guys!
Postmaster
Joined: Jan 2005
Posts: 4,743
Likes: 3
From: Peoria, IL
fomocofan, it is widely known here that when you use the 8 oz. recommended by ford the limited slip will only transfer a very limited amount of power to the wheel that has traction, something like 50ftlbs. By cutting the amount of friction modifier down people have been able to get much more power transferred and make the limited slip actually work like it should.
Senior User
Joined: Oct 2004
Posts: 420
Likes: 0
Originally Posted by Beerstalker
fomocofan, it is widely known here that when you use the 8 oz. recommended by ford the limited slip will only transfer a very limited amount of power to the wheel that has traction, something like 50ftlbs. By cutting the amount of friction modifier down people have been able to get much more power transferred and make the limited slip actually work like it should.
I'd like to hear the scientific labratory tests that were done to determine this??
Ok..the average guy has a problem with his rear...and or is replacing old dirty gear lube...then he puts in NEW lube w/o FM and it works better...and then he makes the assumption that this improvement is because he used little or no FM...when more than likely it is because he put in new fluid!!
I suppose you are going to tell me that people on here have tried new fluid with 8 oz of FM and then drained it out and put in more new fluid and less FM...I doubt it!!
People like to believe that there is a miracle and cheap solution to every problem...I think it's called hope or a miracle...but bottom line is that there is a reason for FM...actually two...as already explained...and these results were proved in my link on page 1...where are they test results from the masses?
As I said..i race an 800 hp truck and had pushed Ford LS diffs to the limit..and it was always run with FM..until I went to a true-trac!
Elder User
Joined: Jan 2004
Posts: 819
Likes: 0
From: Troy,NY
Originally Posted by fomocofan
I suppose you are going to tell me that people on here have tried new fluid with 8 oz of FM and then drained it out and put in more new fluid and less FM...I doubt it!!
All my fluids get changed yearly or better since I started doing more agressive off-roading. After installing a new clutch pack in my 30 year old 9 inch I filled it up with gear oil and added almost 8 oz of modifer. I didn't think I was getting the traction I should be so I checked with some of my local old-timer Ford gurus and they said try less modifier. Not none but less and do figure 8's to test it. So I went with 1 oz. It did get better but it would chatter-chirp doing figure 8's. I added anonther oz and back to the figure 8's. No chatter and still good traction. Fast forward a couple of years. I joined a local off-road club and what do you know,
The figure 8's are the same way the guys in my local off road club test their L/S diff's in their Heeps.
Senior User
Joined: Oct 2004
Posts: 420
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Originally Posted by ken75ranger
I'm one of those people. All my fluids get changed yearly or better since I started doing more agressive off-roading. After installing a new clutch pack in my 30 year old 9 inch I filled it up with gear oil and added almost 8 oz of modifer. I didn't think I was getting the traction I should be so I checked with some of my local old-timer Ford gurus and they said try less modifier. Not none but less and do figure 8's to test it. So I went with 1 oz. It did get better but it would chatter-chirp doing figure 8's. I added anonther oz and back to the figure 8's. No chatter and still good traction.
Fast forward a couple of years. I joined a local off-road club and what do you know,
The figure 8's are the same way the guys in my local off road club test their L/S diff's in their Heeps.
All my fluids get changed yearly or better since I started doing more agressive off-roading. After installing a new clutch pack in my 30 year old 9 inch I filled it up with gear oil and added almost 8 oz of modifer. I didn't think I was getting the traction I should be so I checked with some of my local old-timer Ford gurus and they said try less modifier. Not none but less and do figure 8's to test it. So I went with 1 oz. It did get better but it would chatter-chirp doing figure 8's. I added anonther oz and back to the figure 8's. No chatter and still good traction. Fast forward a couple of years. I joined a local off-road club and what do you know,
The figure 8's are the same way the guys in my local off road club test their L/S diff's in their Heeps.
You are only commenting on the chatter...This post is not about chatter..we all know that FM helps chatter!
This post is about FM and how the lack of it or less of it helps the clutches grip or as I say the FM itself helps traction!
you say yourself that varrying the amount of FM still gave you good traction...how is that a test of the traction or posi unit?
You cannot test a LS's traction by fiqure 8 method...only straight line or torque test!
you have to understand that chattering and clutch engagement are two different things my friend!
The chatter comes from the clutch pack engageing and disengageing, while the traction or equal power to both wheels only occurs once the clutches engage and the clutches lock-up.
The FM helps smooth the clutch pack while engageing and disengageing...this is the chatter part...
The FM also helps the clutches engage or lock-up making better traction WHILE ENGAGED..which only happens in a straight line!
NEXT??
Last edited by fomocofan; Mar 18, 2007 at 03:29 PM.
Infidel
Joined: Aug 2003
Posts: 1,115
Likes: 2
From: Elkhorn WI
fomocofan chill out dude.
Even tho ppl have been talking about chatter EVEN THO WE KNOW THIS POST ISN'T ABOUT CHATTERING we still give our .02 to help the guy out if he would have future issues with his truck.(or anyone else down the road that has the same problem)
You have stated many times now what he should do and you have explained how the whole rearend works...so instead of bashing every comment someone makes whether they are wrong or not (in your opinion) you should just chill out and let the thread move on.
Even tho ppl have been talking about chatter EVEN THO WE KNOW THIS POST ISN'T ABOUT CHATTERING we still give our .02 to help the guy out if he would have future issues with his truck.(or anyone else down the road that has the same problem)
You have stated many times now what he should do and you have explained how the whole rearend works...so instead of bashing every comment someone makes whether they are wrong or not (in your opinion) you should just chill out and let the thread move on.
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Elder User
Joined: Jan 2004
Posts: 819
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From: Troy,NY
Originally Posted by fomocofan
That's a great little story...
but it does not prove how you would make a super posi or test one!
but it does not prove how you would make a super posi or test one!
Originally Posted by fomocofan
You are only commenting on the chatter...This post is not about chatter..we all know that FM helps chatter!
Originally Posted by fomocofan
This post is about FM and how the lack of it or less of it helps the clutches grip or as I say the FM itself helps traction!
you say yourself that varrying the amount of FM still gave you good traction...how is that a test of the traction or posi unit?
you say yourself that varrying the amount of FM still gave you good traction...how is that a test of the traction or posi unit?
Originally Posted by fomocofan
You cannot test a LS's traction by fiqure 8 method...only straight line or torque test!
Originally Posted by fomocofan
you have to understand that chattering and clutch engagement are two different things my friend!
Originally Posted by fomocofan
The chatter comes from the clutch pack engageing and disengageing, while the traction or equal power to both wheels only occurs once the clutches engage and the clutches lock-up.!
B. L/S clutches never lock up.
Originally Posted by fomocofan
The FM helps smooth the clutch pack while engageing and disengageing...this is the chatter part...
The FM also helps the clutches engage or lock-up making better traction WHILE ENGAGED..which only happens in a straight line!
The FM also helps the clutches engage or lock-up making better traction WHILE ENGAGED..which only happens in a straight line!
Fleet Mechanic
Joined: Nov 2004
Posts: 1,427
Likes: 10
From: Templeton, Massachussetts
make sure to add the modifier and do a series of side to side turns to set it into the cluthces. if it still slips then you can tighten up the shim pack in the diff.. I have done a few under powertrain warranty..if you are under. if not then about a 3-4hr job at your dealer..
Senior User
Joined: Oct 2004
Posts: 420
Likes: 0
Originally Posted by 18vtx00
make sure to add the modifier and do a series of side to side turns to set it into the cluthces. if it still slips then you can tighten up the shim pack in the diff.. I have done a few under powertrain warranty..if you are under. if not then about a 3-4hr job at your dealer..
It does not make the clutches slip more as was said originally!
Senior User
Joined: Oct 2004
Posts: 420
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Originally Posted by ken75ranger
Thank you for liking my tale! Can you show me where I said super posi? I must have missed that.
This post is about chatter among other things Do you mean this thread?
The figure 8 test puts the tires in different turning radii. The L/S clutch has to be overcome to allow the outer tire to turn faster than the inner tire.
Maybe you can't but it does work for me as well as others.
Actually I do understand the difference. The chatter is the clutch being overcome by torque. The thing is too little modifier and the chatter is from the clutch engaging too hard making excessive wear on it.
A. The clutch pack is always engaged. It does however slip.
B. L/S clutches never lock up.
Modifier smoothes it out by letting the clutches slip easier. The more modifier you add the more it slips.
This post is about chatter among other things Do you mean this thread?
The figure 8 test puts the tires in different turning radii. The L/S clutch has to be overcome to allow the outer tire to turn faster than the inner tire.
Maybe you can't but it does work for me as well as others.
Actually I do understand the difference. The chatter is the clutch being overcome by torque. The thing is too little modifier and the chatter is from the clutch engaging too hard making excessive wear on it.
A. The clutch pack is always engaged. It does however slip.
B. L/S clutches never lock up.
Modifier smoothes it out by letting the clutches slip easier. The more modifier you add the more it slips.
Once again I qoute Boxcar from page 1
" The friction modifier additive can be thought of as a friction "controller," insuring maximum clutch pack engagement while allowing the conversion from lock to slip to occur gradually."
you will notice the words engagement and lock!!!
You sir do not know of what you speak!!!
Lead Driver
Joined: May 2003
Posts: 9,303
Likes: 48
From: Lyndonville, Vermont
Got this from a racing site!
The advantage to clutch type difs is that they are "tuneable" the disadvantage is that this tuning is hard to do and requires lots of testing...special tools friction modifiers special clutch packs extra shim packs etc. I'll bet stock they locked up early (as they should) and a car with a locked axle goes straight even though the wheel angle tries to force it around the circle...prob the best they could have done is loaded them with the straight BG limited slip friction modifier turning the dif's into open dif's (the stuff is way slippery) done the skid pad and dropped the oil loaded new and changed that two after a few hundred miles. Ah hindsight perfect every time.
Dick
The advantage to clutch type difs is that they are "tuneable" the disadvantage is that this tuning is hard to do and requires lots of testing...special tools friction modifiers special clutch packs extra shim packs etc. I'll bet stock they locked up early (as they should) and a car with a locked axle goes straight even though the wheel angle tries to force it around the circle...prob the best they could have done is loaded them with the straight BG limited slip friction modifier turning the dif's into open dif's (the stuff is way slippery) done the skid pad and dropped the oil loaded new and changed that two after a few hundred miles. Ah hindsight perfect every time.
Dick
Senior User
Joined: Oct 2004
Posts: 420
Likes: 0
Originally Posted by 99f350sd
Got this from a racing site!
The advantage to clutch type difs is that they are "tuneable" the disadvantage is that this tuning is hard to do and requires lots of testing...special tools friction modifiers special clutch packs extra shim packs etc. I'll bet stock they locked up early (as they should) and a car with a locked axle goes straight even though the wheel angle tries to force it around the circle...prob the best they could have done is loaded them with the straight BG limited slip friction modifier turning the dif's into open dif's (the stuff is way slippery) done the skid pad and dropped the oil loaded new and changed that two after a few hundred miles. Ah hindsight perfect every time.
Dick
The advantage to clutch type difs is that they are "tuneable" the disadvantage is that this tuning is hard to do and requires lots of testing...special tools friction modifiers special clutch packs extra shim packs etc. I'll bet stock they locked up early (as they should) and a car with a locked axle goes straight even though the wheel angle tries to force it around the circle...prob the best they could have done is loaded them with the straight BG limited slip friction modifier turning the dif's into open dif's (the stuff is way slippery) done the skid pad and dropped the oil loaded new and changed that two after a few hundred miles. Ah hindsight perfect every time.
Dick
That's funny stuff right there...
What a joke...some "racing site"! any racing site that says something is "way slippery" cannot be taken seriously!!
It is obvious that people have a misconception about friction modifiers!
please take them time to do alittle research on them...you could check the torco link in my page one post!
Last edited by fomocofan; Mar 18, 2007 at 08:08 PM.