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your .02 on my 7/8 rotors

Discussion in 'Early CJ5 and CJ6 Tech' started by wheelie, Mar 9, 2012.

  1. Mar 9, 2012
    wheelie

    wheelie beeg dummy 2024 Sponsor 2023 Sponsor

    York, PA
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    I know the hot set up is the disc brake upgrade using the 1 1/8 thick rotors but, I have a dana 30 here that has the 7/8 thick rotors on it. I don't have any calipers, though. So, what do you guys think. Should I just use the stuff I have or hold out for the thicker rotors and go that route. Running 33 x 9.50's. Maybe 10.50's someday but, can't see going any bigger. And, no, I don't want to swap in the whole Dana 30. Just not what I want. So, uhh, whatduya think?
     
  2. Mar 10, 2012
    '74Renegade

    '74Renegade Active Member

    Fair Oaks, CA
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    I say use what you have, calipers should be easy enough to come by if you want to buy new. I came across a 7/8 setup awhile back and figured I'd give it a try, the price was right. I haven't read anything about greater stopping power on the 1 1/8, just better heat dispersion. As long as you aren't riding your brakes, I don't think it will matter.
     
  3. Mar 10, 2012
    cpt logger

    cpt logger Member

    Western Colorado
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    The Jeep is fairly light. Disc brakes will be a huge upgrade over the drum brakes. As 74 Renegrade has said, unless you are riding your brakes for long distances, you will not overheat them. The stopping power of the 7/8 brakes should be very comparable to the 9/8 = 1 1/8 inch discs. If it were my rig, I would use the ones I have. IHTH, Matt W.
     
  4. Mar 10, 2012
    jayhawkclint

    jayhawkclint ΜΟΛΩΝ ΛΑΒΕ

    Oklahoma City, USA
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    The 7/8" work fine. I actually had to switch from semi metallic to organic pads on my 1-1/8" setup because they ran too cool due to such a light vehicle. I ran 7/8" on my old green Heep with 33" swampers and they worked great.
     
    Last edited: Mar 10, 2012
  5. Mar 10, 2012
    47v6

    47v6 junk wrecker! 2023 Sponsor 2022 Sponsor

    USA
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    the best parts i have found that work perfect every time are the free ones. i cannot stress that enough. the top of the line brand are free parts. i cannot recommend them highly enough!
     
  6. Mar 10, 2012
    Daryl

    Daryl Sponsor

    Bonney Lake, WA
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    I just bought a set of new rotors for a later 7/8" setup and they were $28 per rotor. The same brand 1 1/8" were $64 a piece. The skinnies were on the shelf and the thick ones had to be ordered. The calipers for a 82-86 were $18 apiece and again on the shelf as they are a common GM caliper. The 77-78 calipers were $38 a piece and you guessed it, had to be ordered. Pretty easy choice if they were side by side for the same initial cost, I would take the 82-86 knuckles every time regarless of the internet lore of the thicker rotors being soooooo much better.
     
  7. Mar 10, 2012
    mortten

    mortten I can’t put my finger on it 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Peninsula, Ohio
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    Had 1 1/8 on the 27. Swapped it with a 30 that already had the 7/8 setup on it. Noticed no differnce. PS: swap in the 30;)
     
  8. Mar 11, 2012
    nickmil

    nickmil In mothballs.

    Happy Valley, OR
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    There is nothi g wrong with the thinner rotor set up. I like and use the thicker rotor setup because I can and have lots of parts at my disposal. They do resist fading a little better. For 99% of Jeepers this isnt an issue.



    Sent from my iPhone using Tapatalk
     
  9. Mar 11, 2012
    w3srl

    w3srl All-around swell dude Staff Member

    Port Orange, FL
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    The thicker rotors are used in the conversions because they line up the caliper better with that setup. Nothing wrong with 7/8" rotors at all.
     
  10. Mar 11, 2012
    oldtime

    oldtime oldtime

    St. Charles,...
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    Not to forget about the weight factor for the ultra light jeep.
    Obviously the narrower rotor is a lighter rotor.
    And the CJ 11" Bendix drums weigh even less.
    Then comes the CJ 10" Wagner and finally the CJ 9" Bendix drum brakes.
    So basically it's mass and weight vs stopping power.
     
  11. Mar 11, 2012
    Posimoto

    Posimoto Hopeless JEEP Addict

    Minden, Nevada
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    I could be off base on this, but I thought that the calipers for the 7/8" rotors bolted directly to the D30 knuckles and that's why people use the 1 1/8" rotors for D27 conversions as you use the GM caliper bracket that mounts over the spindles. Am I incorrect on this? In other words, aren't the caliper mounts cast into the knuckles for the 7/8" calipers?
     
  12. Mar 11, 2012
    '74Renegade

    '74Renegade Active Member

    Fair Oaks, CA
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    Yes, you need the knuckles to use the 7/8 rotors.
     
  13. Mar 11, 2012
    Posimoto

    Posimoto Hopeless JEEP Addict

    Minden, Nevada
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    So Wheelie, I read your first post to mean you were using the D30 discs to convert a D27 and didn't want to put the D30 in. Is that correct? Maybe I just mis-understood it. If you are converting a D27 you pretty much need to use the 1 1/8" rotors. But I could be wrong.
     
  14. Mar 12, 2012
    '74Renegade

    '74Renegade Active Member

    Fair Oaks, CA
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    Will the D30 disc knuckles not work on D27? Something to do with the closed knuckle I suspect?
     
  15. Mar 12, 2012
    wheelie

    wheelie beeg dummy 2024 Sponsor 2023 Sponsor

    York, PA
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    RATS! And I was just getting excited about having parts I could use. Yes, I was hoping to use the 7/8 rotors on my 27 and have no interest in installing the complete 30 (it's just me being me).

    So, unless there is a caliper that will work with both the 7/8 rotor and the chevy caliper mount bracket (since I just learned the 7/8 jeep caliper mount bracket is not usable on the 27), then I might as well go the 1 1/8 rotor route and send these 30's to the swap meet.

    Mike, no the 30 knuckles will not work on the 27. Completely different designs between open and closed knuckle, as you suspected.
     
    Last edited: Mar 12, 2012
  16. Mar 12, 2012
    '74Renegade

    '74Renegade Active Member

    Fair Oaks, CA
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    Yep, just hit me after reading posimoto's previous post. I think I was just excited about the thin disc setup as I am doing this swap right now on my D30.
     
    Last edited: Mar 12, 2012
  17. Mar 12, 2012
    mortten

    mortten I can’t put my finger on it 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Peninsula, Ohio
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    NAPA has the 1 1/8" rotors for $45.00. Part number NB 4885667.
     
  18. Mar 12, 2012
    Mcruff

    Mcruff Earlycj5 Machinist

    Albertville, AL
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    Put the dana 30 in and quit being stubborn. The benefits of the dana 30 are huge over the dana 27. Better turning, no knucklepudding, cleaner driveway (see knuckle pudding comment), better turning radius, better locker choices, better parts availability, tighter steering overall.
     
  19. Mar 12, 2012
    Posimoto

    Posimoto Hopeless JEEP Addict

    Minden, Nevada
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    ... better spline counts on the axles... One of the best upgrades I've done for the old Heep.
     
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