Page 1 of 2 12 LastLast
Results 1 to 10 of 13

Thread: How much slack is too much in a differential?

  1. #1
    Join Date
    May 2010
    Location
    Modesto, California-The Valley
    Posts
    984

    Default How much slack is too much in a differential?

    Ok guys, i know i have been asking a lot of questions here lately, but I have another one. After the install of the lock rite in the rear axle (IFS width toyota 8") I notice that I have some sloop back there. Now, the front has the same exact setup and once the hubs are locked in, you can only move the yoke, by hand, about 1/4" at most before it stops. The rear axle, i can turn it almost a quarter of a turn before it stops. That seems like a lot of slack back there and all I did was install the locker and put the carrier back together the exact same way as I removed it. The bearing retainers and lock was put back in the same location as per the instructions. Never tested the slack before the install but just noticed it afterwards. It makes 2wd turning very difficult as the slack in diff will go limp then catch as the tranny keeps spinning and makes the jeep jump. Once it jumps once, the locker kicks in and not only starts to stop the jeep but when the slack comes out again, it launches the jeep again and agin until i clutch it and start over and make sure I keep preasure on the rear axle (by using the granny gear and constant preasure). If need be, i can drop the rear drive line and take a short video of the amount of slack I have but I would like to know how much slack is too much. I have been searching online and havn't found anything solid and will be making further phone calls to shops but would like to try here. Thanks.
    1972 CJ5 AMC 304, NP435, Twin Stick Dana 300, Toyota 8" front and rear, both with 4:56's and lock rights, 35" BFG KM2's, toyota rear springs on all 4 corners.
    Photos to ALL build pictures of the jeep. Not in order for the first few pages. http://photobucket.com/1972JeepCj5

  2. #2
    Join Date
    Sep 2002
    Location
    Portland, OR
    Posts
    9,412

    Default

    Did you check backlash when you reassembled it? Needs checked with a dial indicator. A pattern check should have been done as well.
    Most auto lockers do have a lot of slack in them. If they didn't they would cause dangerous handling issues when hitting ruts or mild curves during normal high speed driving. What you describe is excessive though.


    Sent from my iPhone using Tapatalk
    '59 CJ-5 modified, '59 CJ-6 more modified, stock '57 CJ-5, Koenig PTO winch

  3. #3
    Join Date
    May 2010
    Location
    Modesto, California-The Valley
    Posts
    984

    Default Re: How much slack is too much in a differential?

    From the toyota forums I have been searching, people are saying it aint no big deal. Maybe so, im not sure. It is new to me driving the jeep with this type of locker in the rear as well as a very soft suspention. I will take a small video of it tomorrow and post it here so everyone can see how much I am talking about. Im not the best at describing things sometimes.
    1972 CJ5 AMC 304, NP435, Twin Stick Dana 300, Toyota 8" front and rear, both with 4:56's and lock rights, 35" BFG KM2's, toyota rear springs on all 4 corners.
    Photos to ALL build pictures of the jeep. Not in order for the first few pages. http://photobucket.com/1972JeepCj5

  4. #4
    Join Date
    May 2010
    Location
    Modesto, California-The Valley
    Posts
    984

    Default Re: How much slack is too much in a differential?

    Ok guys, here is a short video I took today showing how much slack or play I have in the rear diff. What do you guys think?
    1972 CJ5 AMC 304, NP435, Twin Stick Dana 300, Toyota 8" front and rear, both with 4:56's and lock rights, 35" BFG KM2's, toyota rear springs on all 4 corners.
    Photos to ALL build pictures of the jeep. Not in order for the first few pages. http://photobucket.com/1972JeepCj5

  5. #5
    Join Date
    Dec 2005
    Location
    Clarkston, WA
    Posts
    1,738

    Default Re: How much slack is too much in a differential?

    I've seen about that on others. Additionally, you've got some spring wrap occurring and you weren't putting much torque to it. I imagine when accelerating your suspension is twisting up big time. This may be a big part of what you are feeling.

  6. #6
    Join Date
    May 2010
    Location
    Modesto, California-The Valley
    Posts
    984

    Default Re: How much slack is too much in a differential?

    I checked my axle wrap before ever driving the jeep. On the street, in 2low and in granny gear, I started a power brake and kept on it until it broke loose and it will only go about 1 inch or so more then what it is. There is a gap between the springs and that fat overload spring on the bottom so it will move easily untill that gap is closed and then thats all the movement it gets...not enough to bind anything. Im just wanting to make sure that the amount of slack in the rear diff aint enough to start hurting anything. As i said, this is the first time i have drove anything with super soft suspension, rear ratchet locker and short wheel base so it may just be a learning learning curve with driving the jeep.
    Last edited by '72CJ5; 08-18-2012 at 09:06 PM.
    1972 CJ5 AMC 304, NP435, Twin Stick Dana 300, Toyota 8" front and rear, both with 4:56's and lock rights, 35" BFG KM2's, toyota rear springs on all 4 corners.
    Photos to ALL build pictures of the jeep. Not in order for the first few pages. http://photobucket.com/1972JeepCj5

  7. #7
    Join Date
    Dec 2005
    Location
    Clarkston, WA
    Posts
    1,738

    Default Re: How much slack is too much in a differential?

    I looked at your video again today on a bigger screen and you have a lot of movement at the spring pad. Should be none. There are gaps in the leaves and the pad itself moves. I would fix that before worrying about the locker.
    Rocky
    '70 CJ-5 "Pete"--Stealthy
    http://photobucket.com/rocky-hensley-engine-rebuild

  8. #8
    Join Date
    Feb 2009
    Location
    exploring the woods of Maine
    Posts
    1,259

    Default Re: How much slack is too much in a differential?

    noticed not much slip yoke...
    The difficult is no problem..............The impossible just takes a little longer
    ........I didn't get a Jeep to go fast..........
    74 with a glass tub , 8274 winch and the right combination of wheelbase, width. line and nuts.
    76 cj7 all glass the loving brides ride, and a handful of parts rigs

  9. #9
    Join Date
    May 2010
    Location
    Modesto, California-The Valley
    Posts
    984

    Default Re: How much slack is too much in a differential?

    drive line is good, doesnt have any issues upon compression or drop even with the entire rear axle at full drop. As for the springs, yes there is some movement. Im not running an axle wrap bar which means there will be some movement....as does every leaf spring set up in the world that does not run a wrap bar. What i was saying is that there is NOT enough wrap on the diff to cause any problems. I have checked and re-checked and nothing binds. besides, this thread is about slack in the diff, not my leaf springs or drive line.
    1972 CJ5 AMC 304, NP435, Twin Stick Dana 300, Toyota 8" front and rear, both with 4:56's and lock rights, 35" BFG KM2's, toyota rear springs on all 4 corners.
    Photos to ALL build pictures of the jeep. Not in order for the first few pages. http://photobucket.com/1972JeepCj5

  10. #10
    Join Date
    Feb 2009
    Location
    exploring the woods of Maine
    Posts
    1,259

    Default Re: How much slack is too much in a differential?

    was only stating an opinion, personally i think there is excessive slack there but have no exp with a lockright type unit...
    The difficult is no problem..............The impossible just takes a little longer
    ........I didn't get a Jeep to go fast..........
    74 with a glass tub , 8274 winch and the right combination of wheelbase, width. line and nuts.
    76 cj7 all glass the loving brides ride, and a handful of parts rigs

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •