[sorta long post sry] rear differential questions/problems

Discussion in 'General IH Tech' started by 76scoutII, Jun 24, 2005.


  1. 76scoutII

    76scoutII Farmall Cub

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    I have a 76 scoutII with D44 front and rear.
    I took a nice 100 mile road trip to the desert a few weekends ago, and then a new noise surfaced on the way back from that trip. I think it is the rear diff. Let me explain how it happens and we'll see what the Binder experts suggest.
    The issue started with a broken tranny stud, which i since replaced with all grade 8 hardware, and repainted the crossmember and a new poly mount, well I thought the noise was from the tranny being all loose and missing a bolt, I was wrong. still does it.
    if i go full crank left or right,a nd get on gas even 1/4 throttle, the noise starts. it is a CLUNK CLUNK CLUNK and increases if i go faster, and if I cahnge gears, it does it the same, does go from slow to fast. it is definitely related to how fast the tire is rotating, not how fast the driveshaft is rotating. Then, as a test, I tried to go to a local dirt field, and got full crank, left and then right, and it does it consistently, and as i look at the driver side rear wheel, as it is clunking, the wheel sorta 'jerks' in perfect correspondence with the sound of the clunking noise. so the clunk clunks, and then the tire sorta jerks, almost like I had a locker or something, which I dont have.
    I think i have the stock powertrac or power lok limited slip, the one with no clutches.
    anyone have any ideas/suggestions on how to fix this??
    I think the best bet is save up 7-800$ and get a detroit locker. on that note, is that something I could do, or does the R&P have to be reshimmed and redone since the detroit is a new carrier? I imagine i cant just pull the old one and bolt the detroit to my ring gear, and have it line up. I know a detroit is about 500$, so how much should I expect to pay to have a shop install it.
    sorry for the lenghty post guys, I hope you can understand my symptom from my description, because it is really hard to describe.
    thanks for any responses!!
     
  2. JackJ

    JackJ Farmall Cub

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    First check your U joints on the driveshaft.You can also check if your ring and pinion gears are worn by putting parking brake on,car in neutral,get under and try to rotate driveshaft by hand.(It should ony rotate 1/8 to 1/4 turn,if more than that they are worn out).Chock up the front wheels,put Scout rear on jackstands(leave floorjack under rear axle center for safety).Make damn sure your transfer case is in 2wd H (front hubs unlocked also) and have someone start and run the car while you watch and listen for noises in the rear axle and watch for wheel wobble.Wobble(excessive) in rear wheel means you have a bent axle(ruining the rear wheel bearing).If not shut it off.Put transfer case in 4wd(lock hubs) put in gear so car will not move while you get under and remove the rear axle differential cover.Look for chewed up gears and excessive crap in the oil you drained out.These 2 things will tell you immediately if your diff is bad(noisy).If you can'tsee any damage you have a bad carrier or pinion bearing. If there is a locker in there the (clutch dogs or springs are trashed making a clicking soundtoo.Good luck and go for it!
     
  3. timscout1

    timscout1 High Wheeler

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    Your limited slip has clutches in it and they are dragging :eek: not a big deal you need to add a tube of the limited slip additive you can get at most parts stores. Add one and drive awhile to see if it goes away if not then add a second one and that should fix the problem unless the clutch packs are completly worn out. This is a very common problem with this style of limited slip. Put the additive in even if the EP oil says for limited slip diff.
     
  4. Erik VanRenselaar

    Erik VanRenselaar Y-Block King

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    I'm thinking a broken tooth on a side gear in the carrier would have the same symptom. You should jack up the rear axle, remove the rear diff cover, and inspect things in there.
     
  5. J.D.Oldham

    J.D.Oldham Binder Driver

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    Eric, hit the nail on the head, you got to look first. I would look at the spider gears too. :mad:
     
  6. ScoutmanSV

    ScoutmanSV Y-Block King

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    Yeppers, pop the cover & see what ya got going on in there. :)

    I may be able to help ya out on a Detroit Locker too. I've got one for 4.09 & above that I can't use (I'm running 3.73) but another member here is interested. If he decides to pass (he already has Tru-Tracs installed) then you're next on the list. :)

    Email me: SSV001@gmail.com & we can discuss what I want for it (you'll be very pleased! ;) ), shipping (I have your addy somewhere, but I think you moved), etc. :cool:

    HTH,

    :D
     
  7. Afireinside2285

    Afireinside2285 High Wheeler

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    Ive had the same thing happen on two of my rear axles,both were out of a 79 sII.Pop the cover and look by the time mine was making the noise yours is I had wiped out both spiders and sides.In both axles the ring and pinion were still good.I ended up putting in a 14 bolt(figured my driving style is to ruff for dana 44).
    As for options you have a few
    1.Find a complete used rear end(probably the cheapest)
    2.IF your R&P is still good you could buy a lunch box locker and install it without resetting gears(only if it is NOT a power lock)
    3.Put in an a full case locker(detroit,arb,etc...)but you will have to reset the gears for that one.
    Good luck.
     
  8. Erik VanRenselaar

    Erik VanRenselaar Y-Block King

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    When I said *side gear*, I also should have referred to the pinion (spider) gears, too. I meant any/all of the *little* gears inside the carrier.
    A simple inspection of the differential innards should reveal the problem. As I earlier stated, jack up the rear. This is so you can turn the wheels (= axleshafts) by hand to get a better look at the diff guts.
     
  9. 76scoutII

    76scoutII Farmall Cub

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    I decided to check the rear driveshaft and ujoints. the drive shaft has 1/8 turn of free play. That would rule out the R&P or any of the bearings related to them right? I then removed my driveshaft, the ujoints all turn and flew properly, and the transfer case output spins freely in neutral. I then locked the hubs and drove around a bit in front wheel drive. No pops or bangs or clunks from the rear or from the front. This tells me that my rear diff is definitely the issue, but now I wonder, if I were missing gear teeth, would the clunking noises still happen, or will they only skip or clunk if they are actually under a load from the engine?? I drove in tight circles like the other day, and reversed as well, and absolutely no noise at all from the rear.
    So what do you guys think now, maybe it is just low on limited slip additive??
    I have 3.54 gears front and rear, but if I had higher, I would take you up on that offer scoutmanSV, unless of course you happen to have a gearset for sale also??
     
  10. 76scoutII

    76scoutII Farmall Cub

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    oops, I meant to say "the ujoints all turn and flex properly"
     
  11. Ricky77

    Ricky77 High Wheeler

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    I had similar noises and added 2 tubes of limited slip addative (from NAPA but I can't remember the name) and it quit clunking. If the clutches in the rear end can't engage properly then there will be noise. On a side note before I added the addative only one tire would really "grab" in the rocks, after the addative I can turn both of them. Even if one tire is in the air the other will grab (not like a locker does but enough to get em moving) but I think that's due to having new clutches. HTH

    Ricky 77
     
  12. Erik VanRenselaar

    Erik VanRenselaar Y-Block King

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    I would *still* jack up the rear axle, remove the diff cover, drain the fluid, and inspect the internals for damage or debris in the housing. With the rear driveshaft off, you can easily perform a cursory ring & pinion backlash check, too.
     
  13. jrowe

    jrowe Farmall Cub

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    I have a 78 SII w/ a D44. I drove it from Cali to Utah and by the time I got to Utah it was making crazy KUNG, KUNG, KUNG noises too. It only makes the noises when I go slow and especially when I turn. Once I get up to 20 MPH or so the noises go away.

    I pulled the DIff cover and all the teeth are fine and there are no shavings in the oil. It's been a long time since it's been changed though. I put the back end on jakcstands and ran it and there is no noise, but when the engine is off and the tranny is in N, i can turn one of the back wheels and feel/see clicking as the spider gears turn in the limited slip.

    Is this going to be fixed by refilling the diff and adding limited slip additive?

    WIll the problem persist if my clutches are worn? If so, how can I tell if they are worn and need to be replaced?
     
  14. jrowe

    jrowe Farmall Cub

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    I have a 78 SII w/ a D44. I drove it from Cali to Utah and by the time I got to Utah it was making crazy KUNG, KUNG, KUNG noises too. It only makes the noises when I go slow and especially when I turn. Once I get up to 20 MPH or so the noises go away.

    I pulled the DIff cover and all the teeth are fine and there are no shavings in the oil. It's been a long time since it's been changed though. I put the back end on jakcstands and ran it and there is no noise, but when the engine is off and the tranny is in N, i can turn one of the back wheels and feel/see clicking as the spider gears turn in the limited slip.

    Is this going to be fixed by refilling the diff and adding limited slip additive?

    WIll the problem persist if my clutches are worn? If so, how can I tell if they are worn and need to be replaced?
     

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