No limited slip in my v6.....

Discussion in '2005 - 2014 Specific V6 Tech' started by echo7, Mar 31, 2005.


  1. echo7

    echo7 Member

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    I was told in a thread before the server crash that there where limited slips in the v6's stock, but today i made sure to look when my car was up gettin my new bullitt rims put on, spin the tire one way, the other spins opposite, so no limited slip. I asked the guy and he looked at the label and told me it was just a plain rear end. He also noted that just about any 7.5" from old rangers and what not would work so i might plan on doing that someday...
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  2. 88GTsocal

    88GTsocal New Member

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    If you're going to go through the trouble of swapping rear ends, why don't you just go with an 8.8 or an aftermarket 9 inch?
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  3. echo7

    echo7 Member

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    well, money...
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  4. RangerMan

    RangerMan New Member

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    Don't go with a 9-inch you won't be making the power to use all that beef and will just end up being slower.

    Wait around for the wrecked GT's to start showing up and grab the 8.8" off one for cheap
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  5. cobra232

    cobra232 New Member

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    why? the 8.8 isn't much stronger than the 7.5

    my procharged 98 3.8 with a 7.5 rear is hlding up just fine

    if you want a LSD i suggest an Auburn LSD Jeg's part#109-542023

    here is a link
    http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=1189&prmenbr=361
    the auburn is more expensive than a ford T-lok but it is far stronger. the differential is the weakest point in a 7.5
    the auburn unit greatly strengthens the 7.5

    you can also add a rear girdle and stud kit for added strength from TA Performance
    part# TA 1805 girdle
    part# TA 1816 stud kit
    here is a link
    http://www.taperformance.com/rearend.htm
    #5
  6. LIZARDKING

    LIZARDKING Member

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    Im putting 3.73s and a T-Lok in my 7.5. If I went racing alot I would upgrade to a 8.8. The 7.5 is fine for 99% of us.

    Forget finding a 8.8 out of a 05 Mustang in the j-yard. Rebuilders will grab all but the worst of the wrecks, the cars being parted will command high prices and be in great demand.

    I dont even know if the gears are all that necessary, I think the T-Lok will make a world of difference. The only reason Im installing both is becasue I scored the gears for $70, and I may as well since I will have the whole rear apart anyway.
    #6
  7. echo7

    echo7 Member

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    Yeah, i can get on of those auburns on ebay for less than $100...
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  8. ChaosStarter

    ChaosStarter Founding Member

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  9. echo7

    echo7 Member

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    #9
  10. Openminds

    Openminds New Member

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    I think a limited slip will spin opposite. My Chev Avalanche has the Factory Eaton locker and I'm pretty sure it spins opposite. Just find yourself a little water and test away. (will be fun finding out anyhow)
    #10
  11. fazm83

    fazm83 New Member

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    Limited slip differentials will spin the opposite way, and a posi rear will spin the same direction.
    #11
  12. echo7

    echo7 Member

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    i think limited has a clucth right? when slipping, it engages, thus the opposite wheel spin. but what does posi have/do?
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  13. Svtpilot

    Svtpilot Founding Member

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    There seems to be alot of miscinceptions about Diffs so here we go, differentials 101:
    There are 3 types of differentials:
    Open rears
    Limited Slips
    Spools a/k/a Locked rears
    Limited slip and Posi are the same thing (and BTW altough "posi" has become a generic term for limited slip like "Coke" is for cola, it is actually a Chevy term. Fords have Traction-lok). Limted Slip rears use clutches, though some like a Detriot Locker use a ratchet assembly, to send power to the wheel with traction. Since normally both wheels have equal traction, when you light up the tires on a limited slip equipped car both tires will spin.
    An open rear sends the power to the wheel with less restistence. which is why you see cars stuck with one tire on snow spinning like crazy and one tire on dry pavement not moving.
    Lastly are Spools or "locked rears" which are used excuslively in Drag Racing. Technically Spools are not differentials. Spools have no spider gears, just a solid piece of metal with the Ring Gear Bolted to it and splines for the Axles. With Spools both tires spin at the same speed all the time regardless od conditions. This makes turning difficult since when you turn the outside wheel covers more ground then the inside and therefore has to spin faster.(Which is why cars have differentials in the first place,to allow the wheels to spin at DIFFerent speeds.) Because of this Spools are no good for street use.
    Normally when on a lift if you spin the tire on a car with an open rear they ill spin in the opposite direction. With a posi the will spin in the same direction and of course the same is true with a Spool. This is true probably 95% of the time, but it is not a 100% accurate way to detremine what type of Diff a car has. The only sure way is to pull off the cover and look at it.
    As far as the 7.5 rear. My 1985 GT came with a 7.5 and it was junk. Maybe Ford has beefed it up since 1985 I don't know. i can tell you that I blew mine apart about 3 months after I got my car, then again about a year latter. I ended up swapping it for a 8.8 in 1987 (when the 5.0 came with 8.8) And remember back in 1985 my 5.0 Mustang GT had the same 210hp as your V6s. If I had a 7.5 equipped car I would probably swap it for an 8.8.
    #13
  14. sam_abuelsamid

    sam_abuelsamid New Member

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    You are basically correct here but I would like to elaborate a little. There are quite a few different mechanisms for limited slip differentials. There is your basic clutch pack lsd (like various fords including the mustang use). There are also other types of clutch based systems, like conical clutches (I forget which brand uses these). There are worm/gear based systems like the Torsen and Quaife. There are locker types which if I recall correctly using some sort of centrifugal clutch and locking mechanism. There are also viscous coupling systems which use interleaved plates in a silicone fluid. In short there are many different kinds, and they have different locking and torque transfer characteristics. One thing they all have in common is that at low speed differentials (Such as spinning one tire on the hoist) the wheels will spin in opposite directions.

    The reason they are "limited slip differentials" is because up to some threshold, they act as an open diff. Once the speed/torque differential across the differential exceeds some threshold, they start to transfer torque from the slipping wheel to the non-slipping wheel. Spinning one wheel when the car is on a hoist proves nothing. One last thing to keep in mind is that the ford lsd is a pretty crappy and even the 8.8 inch doesn't transfer much torque. The Traction control system is much more effective than the lsd.
    #14
  15. Openminds

    Openminds New Member

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    Well said!

    Ok, here is one.... In the past I had noticed that if the vehicle was equipped with one of these locking diffs, you were required to run an oil with either an additive, or synthetic. My truck requires a synthetic lube while another friend's Truck (Same year) has an open rear requiring only a standard 90w or something. My mustang has a label right on the diff stating synthetic lube only. Is this a sign of a locking/limited slip, or just a requirement for all newer Ford diffs?
    #15
  16. NJstangpilot

    NJstangpilot New Member

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    SVTpilot is correct, but there are actually five main types of differential. They are: Open, Clutch type (limited slip), Viscous Coupling, Locking, and Torsen. To read an excellent explaination of the various types and how they work (including pictures of each), follow this link …

    http://auto.howstuffworks.com/differential.htm

    It should answer any questions you have. This is a great site, BTW.
    #16
  17. Svtpilot

    Svtpilot Founding Member

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    Hey I said it was "Differentials 101" Now you're giving them Differentials 2 or Advanced DIffs :D
    As far 7.5 vs 8.8 I wasn't speaking about the ability to transfer power, I was refering to durability. Unless Ford has improved it over the years which is possible, the 7.5 is no where near as durable as the 8.8. And I agree that spinning a tire is not a sure way to determine the type of diff, as I said the only sure way is to pull the cover and look at it. However in most cases they will react as I stated.
    #17
  18. sam_abuelsamid

    sam_abuelsamid New Member

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    Sorry, I wasn't trying to dispute what you said, just elaborate a little for the sake of anyone who was interested. I am just trying to share the benefit of some the experience I gained over the years to slip control development (abs/tc/vsc) and testing vehicles with different drivetrain configurations. You are right that the 8.8 should be more durable than the 7.5 axle. However, there have been a lot of advancements in metallurgy, metal forming and machining and heat treating in the last 20 years, and a 7.5 diff today is undoubtedly more durable than one from 15-20 years ago. The limited slip mechanism that ford uses in there traction-lok still blows though, and tc will give you more benefit than the oem lsd. Many of the aftermarket units are better than the factory unit, but whether they are better than the tc and worth the cost is a question I will leave open for now.
    #18
  19. Svtpilot

    Svtpilot Founding Member

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    No I didn't think you were , I was meant that your post (and your knowledge :nice: ) was much more in depth then mine. I was being very basic. Regarding TC vs Traction -lok,and which is better, my opinion is that it depends on what the indivua who started the thread l is looking for. If he is looking for superior performace and control in snow , rain , lose surfaces and other conditions of poor traction, then TC is by far the way to go. If anything Traction -lok makes the car less contollable then and open diff under these conditions since Traction -Lok equipped cars have a tendency to swing the tail out when the tires break lose.There is no question in my mind which is better here. TC all the way.
    However if he is looking to put power down onto dry pavemnt for straight line acceleration then Traction -lok is the way to go . In this case TC will slow him down.
    #19
  20. LIZARDKING

    LIZARDKING Member

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    Ok, lots of info flying around here.

    The 7.5 is fine for 99% of the people driving the 05 V6 Stang. Is it as good as a 8.8? No, not even close. Anyone who tries hard enough can break any rear end made. Ive had Mustangs with both the 7.5 and the 8.8, I was happy with both. Look at the thousands of Mustangs made with the 7.5 that have been on the road 20+ years. The T-Lok is also not the best traction control made, but again it's doing the job in thousands of Mustangs on the road today.

    Bottom line: How much do you want to spend?

    Im going with my 3.73s and T-Lok, I think that is the best performance mod I can make for the money spent.

    BTW, The clutches in a T-Lok wear out over time/abuse. When shot, it will act like an open diff. So, spinning one wheel isnt necessarly a sure way to tell if you have a T-Lok or not.

    My T-Lok ran $200 + $75 for used 3.73s, add in the cost of the install kit + labor + the reflash to correct the speedo. Gears and a T-Lok arent cheap, even when you go the low budget route like Im doing.
    #20

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