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Limited Slip Recommendations?

Discussion in 'Early CJ5 and CJ6 Tech' started by Henri Watson, Jan 23, 2020.

  1. Jan 23, 2020
    Henri Watson

    Henri Watson Member

    Mississippi
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    Oct 27, 2018
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    189
    I'm thinking a limited slip might be a nice addition to my '66 CJ5, ultimately I'd like to have one front & rear but am I right that if I'm starting off with just one it's better to have it in the rear than the front? It's a 100% mud vehicle so no boulders to deal with here. Would also like any recommendations on reliable brands that perform well.

    Thanks!
     
  2. Jan 23, 2020
    WestCoastPat

    WestCoastPat Member

    Orting, WA...
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    Nov 1, 2015
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    Once you have it installed, you will realize what you have been missing. Simple-Nothing required of you to engage it-Just works.
     
    Lockman likes this.
  3. Jan 23, 2020
    maurywhurt

    maurywhurt Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Western North...
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    When I was in the market for a limited-slip for my Dana 44 rear axle about 8 years ago, I was unable to find an original Powr-Lok, and ended up installing a (made in U.S.A.) Auburn Gear High Performance LS diff. I've been very happy with it, but should note that I drive my jeep mainly on-road, and its off-road use doesn't include rock crawling.

    Auburn also makes the Pro series limited slip, which IIRC uses the same cone type clutch mechanism, but has a higher spring pre-load than the High Performance models.
     
    Last edited: Jan 24, 2020
    Lockman likes this.
  4. Jan 23, 2020
    Bigdaddy13

    Bigdaddy13 Member

    So.Cal
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    Just talked to Herm the overdrive guy and he had PowerLocks front and rear for $500 a pop. Seems like a good price.
     
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  5. Jan 23, 2020
    ITLKSEZ

    ITLKSEZ Hope for the best, prepare for the worst

    Liberty Lake, WA
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    If I can swing it at the end of my build, I’m 99% sure I’ll be going Detroit Truetrac front and rear. No clutches to wear out or fail, no special oil, extremely strong design, and nearly 100% lockup if you add some braking if needed. Completely unnoticeable on the street.
     
    Last edited: Jan 23, 2020
    Ol Fogie, gromit, Jrobz23 and 2 others like this.
  6. Jan 23, 2020
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    Rear.

    These Jeeps came with a Dana Powerlock from the factory. That would be an excellent choice. You may be able to find a used one that matches your axle; they can be refurbished. I hear the Detroit TrueTrac is also good - aftermarket only.

    Agree, LSD is a terrific addition. Jeep offered them on the rear axle on the regular option list. Very popular option.
     
  7. Jan 23, 2020
    Dave Deyton

    Dave Deyton Member

    Fuquay-Varina, NC
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    This is some good info. I like the idea of keeping it stock, with a limited slip, when I get it driving, that is.

    Dave
     
    Renegade ll likes this.
  8. Jan 23, 2020
    Keys5a

    Keys5a Sponsor

    Florida Keys
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    A '66 should have a Dana 27 up front, and with a V6, may have either a 3.73 or 4.88 gear ratio. There are NOS front PowrLoks on ebay for the D27, 4 series, for $140 or $200 depending is they have a little flash rust or are very clean. These are a great buy for a front axle, but you need to know your gear ratio.
    -Donny
     
  9. Jan 24, 2020
    sgogpn

    sgogpn From the top of Lions Back... 2022 Sponsor

    Glendale, AZ.
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    Based on my experience running both Powrlocs and a Trutrac I can say that I wouldn't use a Trutrac again. I tried one in the front of my 7 years ago and it just didn't work as specified. Even trying the brake trick didn't cause it to work as good as a Powrloc. I finally took it out and put a Powrloc in and never looked back. Now to be fair, this was quite a few years ago and they have likely improved them since then but as I said before that was my experience.
    It is true that Powrlocs have clutches that will eventually wear and they do require friction modifier. Big deal. They were good enough for the factory to offer them as an option and after running them for years I now know why. They just work. They're practically unnoticeable on the street and you immediately notice how well they work on the trail. Trutracs claim that they have no clutches to wear out or replace but back when I had one they were not rebuildable when the gears wore out. They claimed to have a greater torque bias than the Powrloc but if you know what you're doing you can do a little magic with a Powrloc and set it as strong or weak as you prefer. I like them for their reliability and rebuild ability. As far as the clutch wear, I put one in the front of my 75 CJ5 27 years ago and Im still running the same clutches that were in it when I put it in. Of course one in the rear will wear clutches sooner but if I have to put new clutches in every 10 years I can live with that. If you hang on to your Jeeps like I do sooner or later you're going to be pulling axleshafts to do bearings or seals anyway and there's no better time to throw new clutches in while you've got it apart.
    I currently have 3 Jeeps with Powrlocs in the front; 2 in Dana 30's, and 1 in a Dana 25, and one in the Dana 60 of my 77F250 Highboy. I buy every used one I find.
    I have also read of guys who have TruTracs front and rear and are very pleased with them.
    I have no experience with the Auburn. I have heard that they are very positive but once the springs get old they are not rebuildable, but again that is hearsay on my part.
    Whichever one you choose, keep us posted and we'll all learn from your experience!

    FWIW,
    Mike
     
  10. Jan 24, 2020
    Bigdaddy13

    Bigdaddy13 Member

    So.Cal
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    Mike, what kind of wheeling do you do?

    I’m looking at the desert, packed sand notches of ocotillo wells, the slickrock of moab and the granite outcroppings of the rubicon as my possible terrains. (Aside from normal sand running and around town pavement driving) Mine will likely be trailered close to the trailhead in most cases.

    Talked to Herm, as i mentioned above and he recommended an SM420 and powerlocks front and rear to build a crawler that wouldn't bust drivetrain parts.
     
  11. Jan 24, 2020
    BadGoat

    BadGoat How High Can You Climb?

    Northern Virginia
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    I ran a TrueTrac in the rear of my JKU on 37s and 40s and it did very well for the 4 years I had it in Alaska running in dirt, rocks, mud, and snow. I have an ARB in the front. My CJ5 is a one wheel peel special until I decide to regear the axles. I have a pair of TrueTracs waiting for the change. I have not run a powerlock so can't give a comparison.

    Mike
     
  12. Jan 24, 2020
    ITLKSEZ

    ITLKSEZ Hope for the best, prepare for the worst

    Liberty Lake, WA
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    I ran powerlocks in a few jeeps years ago. The thing I didn’t like about them was that in order to get them to have any benefits in the rocks, the clutch packs had to be manipulated to be so stiff that they performed nearly like spools on the street. Even when only moderately tight, they repeatedly tried to kill me in the snow. Leave off the gas around a turn in the snow and it always prefers 50/50 bias. They never release and act as a regular open diff like a Truetrac can.

    If I were building something that was going to see more than the occasional hardcore trail, I’d definitely be looking harder at a selectable locker. But for the amount of street use it’ll see, Truetracs sound perfect for my particular build.
     
    melvinm likes this.
  13. Jan 24, 2020
    oldtime

    oldtime oldtime

    St. Charles,...
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    Correct Dana spelling is "Powr Lok" and also there's the Dana "Trac Loc".
    I have had put Powr Loks in the last 8 Jeep axles Iv'e built.
    D25's, D3's and D44's both tapered and flanged versions.

    Yes it's certainly true that they are not ideal for a Jeep that is only used for rock crawling.
    But they are ideal ...for a jeep that is run both on road and widely variable terrain.
     
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  14. Jan 24, 2020
    ITLKSEZ

    ITLKSEZ Hope for the best, prepare for the worst

    Liberty Lake, WA
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    Correct spelling is I’ve.
    :rofl:
    I kid.
     
  15. Jan 24, 2020
    oldtime

    oldtime oldtime

    St. Charles,...
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    Correct axle was supposed to be D30 not D3,,,, Ha Ha Ha !
     
  16. Jan 24, 2020
    Norcal69

    Norcal69 Out of the box thinker 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Northern California
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    :contract:
    This is fact in my experience.
    While the Powr Lok is way better for off road than having open diffs..... But they don't come close to the on road operational friendliness of other diffs.
    I ran a Powr Lok in my ff offset axle for a couple years. When turning from a stop onto a street, the rear tires would chirp.... turning radius also suffered a bit due to the spool effect... differences in tire diameter also add to the rolling resistance and quirkiness.

    Steve's 71 has gleason diffs in front and rear (trutracs are a modern copy), you don't notice they are there on the street. Off road they work excellent... even when you bust your front drive shaft twice and are stuck with 2wd for the next two days of wheeling....:rofl:
    Our jeeps are setup very similar... AT tires, same gearing, similar curb weight ect... his jeep had noticeably less rolling resistance than mine and cornered much friendlier on asphalt.

    The ultimate really is a selectable locker be it ARB, OX, Elec.... but they all cost significantly more than than the variety of limited slips available. I chose ARB because I wanted to add the compressor to my jeep for other conveniences.
    Selectable diffs, when unlocked on pavement, have much less rolling resistance and better manners than the Powr Lok.
    For a jeep that will see lots of pavement duty I would go with something other than a Powr Lok.
    For a jeep that will see more dirt roads than pavement I would only consider a Powr Lok if I either already had one or got a smoking deal on one.
    Of course if you are building a D25 or D27 the Powr Lok is the only option besides a lunch box...... in that event either is better than an open diff offroad...... :whistle:
     
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  17. Jan 25, 2020
    sgogpn

    sgogpn From the top of Lions Back... 2022 Sponsor

    Glendale, AZ.
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    Living in AZ. I get the desert terrain and rock crawling. I've done TDS just about every year for decades, lived in Moab in 79 and have been going back ever since for Jeep Safari, and I guide in Ouray every summer.
    You are correct, if you only have the option for one, rear is better. Since no 2 vehicles are exactly the same and people's driving habits differ there is no perfect LSD or locker for everyone; it becomes a matter of personal preference and availability of units for your particular application, such as your Dana 27.
    Now, a disclaimer of sorts; even though I like my Powrlocs I was introduced to them long before selectable lockers were available. The selectables really are great if your wallet can stand the abuse:rolleyes:. As was mentioned earlier, anything is better than open diffs.
    You've gotten some great advice from the experiences of others on here. Keep us posted and let us know how it turns out.:)

    FWIW,
    Mike
     
  18. Jan 25, 2020
    johnny_boy02

    johnny_boy02 New Member

    Yuba City, CA
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    Buy once and cry once. I would save up and get any kind of selectable locker as long as it’s a ARB. Yukon makes garbage and the price is close enough enough to just get the good stuff.
     
  19. Jan 25, 2020
    homersdog

    homersdog Tulsa, Ok 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Tulsa, OK
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    I recently converted my rear D44 to an OX locker a long with a full float conversion. I have only used the OX locker on a few trial runs on some muddy trails near our neighborhood. That rear axle has been transformed from a cheesy 70s relic to a tank drive! It has absolutely breathed new life into the Jeep.

    In the grand scheme of things spending the extra money to get a selectable locker is well worth it. I think getting a friction based locker is great for drag racing a camaro but if you are going to have a wheel in sloppy mud or hanging off a rock then you need a spool. A selectable locker transforms your differential into a spool.
     
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  20. Jan 25, 2020
    oddfirejeeper

    oddfirejeeper Active Member

    Hamilton, MI
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    Are these lunch box lockers even available? I've looked for years but could not find one for a dana27. 27 spline dana 30's sure..all day long but no dana 27.
     
    Keys5a likes this.
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