72 Skylark rear gears chewed up- HELP PLEASE

Discussion in 'Got gears?' started by Ryanjbill15, Jul 2, 2018.

  1. Ryanjbill15

    Ryanjbill15 Well-Known Member

    Hey guys- I was changing the diff oil today since I don't know when it was done last by the other owner. When I took the cover off I noticed some of the inside gears were chewed up and two metal chunks came out that were stuck in between the housing and bolts. It looks like the ring and pinion are fine but the other gears (name?) are chewed. Attached are pics. This is a 2.56 open rear. What would cause this? It does explain I think when I took turns the one tire slipping/hopping slightly. I chalked it up to so much torque. The large gears seem fine. Is it unsafe to drive now? What do I do?


    Thanks again.
    image3.jpeg image4.jpeg
     
    Last edited: Jul 2, 2018
  2. gstewart

    gstewart Well-Known Member

    Took out the spider gears. Not safe to drive. Maybe too many fast turns or just plain fatique.
     
  3. Ryanjbill15

    Ryanjbill15 Well-Known Member

    Thank you Gerry. Do i need to replace the whole thing to get to spider gears? I am guessing the prior owner did one to many donuts.....I haven't even done a burnout in it yet
     
  4. Ryanjbill15

    Ryanjbill15 Well-Known Member

    ok so got the pin out of the carrier but the axles wont move in or out. Its a 8.5" GM 10 bolt....I knew it couldn't be simple :) Is the C clip hung up on something? are there bolts to? suggestions to move it so I can get the C clip out. I have pounded on it with a hammer and it didn't do anything.
     
  5. Mopar

    Mopar Well-Known Member

    I am no expert, but I believe you need to pull your drums and unbolt your axles, then they will pull out.
     
  6. Ryanjbill15

    Ryanjbill15 Well-Known Member

    Ahhh I see the 4 bolts behind the drum. I'll try that (still learning!)
     
  7. Ryanjbill15

    Ryanjbill15 Well-Known Member

    Took those off and the drum backing plate comes loose but the axle still doesn't move in or out. Neither side budges.

    It may be the bearing stuck. Is there an axle puller or something?
     
  8. 436'd Skylark

    436'd Skylark Sweet Fancy Moses!!!!!

    It's kind of a press fit. Put the drum on backwards and put a couple lug nuts on a few turns. Use the drum as a slide hammer.

    Those are the spider gears. Are you doing a lot of burnouts/ power brakes? The heat stains in the carrier suggest you are or a previous owner beat the hell out of it. Under normal operation those gears don't turn much at all. When one wheel is stationary and the other is going 40 mph they spin much faster than they were ever intended too. They get very little oil and build up a tremendous amount of heat.
     
  9. Ryanjbill15

    Ryanjbill15 Well-Known Member

    Just tried that with no luck. Ill keep yanking at it :) Nope not even one burnout I got the car about 2 months ago. I suspect the prior owner did and I should have known based on the test drive. Oh well live and learn.
     
  10. Ryanjbill15

    Ryanjbill15 Well-Known Member

    Got them out! Nice slide hammer :)
     
  11. BrianTrick

    BrianTrick Brian Trick

    Hard to tell from the pictures,but it looks like someone tried to weld the spider gears to the carrier,to make a permanent spool. It was something guys would do for cheap,but if you don’t weld them right,I could see how it could end up like what you have.
     
  12. Ryanjbill15

    Ryanjbill15 Well-Known Member

    They really looked welded in there. Like you said- hard to tell since it all broke away.
     
  13. BrunoD

    BrunoD Looking for Fast Eddie

    I just took the axles out of my 8.5.I could not take them out even with a sledge hammer,but a young friend was able to do it.So,go rent a sledge hammer,it will do it if you are strong enough.Bruno.
     
  14. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    It's an 8.5, replace it all, and get some real gears:D:D
     
  15. Ryanjbill15

    Ryanjbill15 Well-Known Member

    I got a slide hammer and it popped them right out. Larry- Agreed! I am working with Jim at JD Race to hook me up with some gears. But I am having a hell of a time deciding on 3.08 vs 3.23 with my 28 inch tall tires.
     
  16. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    3.23 with a 28" tire is a 3.07. 3.23 with a 26" tire is 3.30. Does that help? Go with the 3.23's I say.
     
    techg8 likes this.
  17. Ryanjbill15

    Ryanjbill15 Well-Known Member

    Thanks Larry appreciate it. I think that's what I'll do
     
  18. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Yeah, 28" tires for the street, 26" tires for the track.
     
  19. Ryanjbill15

    Ryanjbill15 Well-Known Member

    Do I need to do anything with the torque converter? That is an area I don't truly understand yet. (Still learning)
     
  20. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Only if the cam needs it. .469 gross valve lift doesn't tell me anything.:)
     

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