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Re-gear

Discussion in 'Early CJ5 and CJ6 Tech' started by shaun, Jul 8, 2022.

  1. Jul 8, 2022
    shaun

    shaun Member

    Lebanon, Ohio
    Joined:
    Oct 15, 2015
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    390
    I’m looking to re-hear my CJ. I’m debating on 4.10 or 3.73. I’m running 32” tires on a d44 and d30 NT and a 225 motor. My question is are these RP high or low pinion? And I drive it on 90% road but if I want to go with a wider tire I’m thinking 4.10 but leave room for slight Highway driving. My near future for this jeep is to run a V8 in it so these gears are kinda in between what I’m looking for I believe. Any assistance on this would be great. My 5.38 gears are just too much for my driving
     
  2. Jul 8, 2022
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    Are you running the original Dana 18? How about an overdrive and keep the 5.38 gears?

    Unless you've got some custom axles, I don't think high pinion axles exist for your application. Should be obvious looking at the axles. A high pinion axle places the pinion axis above the center line of the wheels. Low pinion below.

    It would be helpful to put the year/model/equipment in your signature file; then it will appear in each of your posts.
     
    Last edited: Jul 8, 2022
  3. Jul 8, 2022
    jeepdaddy2000

    jeepdaddy2000 Active Member

    Eagle Point oregon
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    Jun 24, 2004
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    Currently running 31" tires and a dauntless.
    I switched from 3.73's to 4.10's when I did my T18 swap.
    IMHO the 4.10's are a tad low for street driving. This has become a bit disappointing since the transmission swap cured the first gear issue.
     
  4. Jul 8, 2022
    Fireball

    Fireball Well-Known Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Pullman, WA
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    I've got a Buick 350 V8 with a T-18, D-18, Warn OD, 3.73 gears, and 32 inch tires. With the stock D18 low range and the T-18 it gives me a 58:1 crawl ratio and 2.8 highway gears in overdrive. The torquey Buick 250 seems to love these gears but I've not tried any rock crawling with it yet.
     
  5. Jul 8, 2022
    SoCalNickG

    SoCalNickG Member 2023 Sponsor 2022 Sponsor

    Whittier, CA.
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    Mar 17, 2017
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    I have a 71 with factory drive train (plus OD); 225-V6, T14, D18, 4.88 gears and Warn OD. I have 30 x 9.5 tires. I love the combo. Freeway speed of 60 to 65 is no problem. Plenty of wheel spin for sand and it did great in Colorado 2 years ago. I still have carburetor and points in the distributor. I have not done any rock crawling, just not my thing.
     
  6. Jul 8, 2022
    shaun

    shaun Member

    Lebanon, Ohio
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    Oct 15, 2015
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    390
    @
    I’m in a 62 M38a1 body with 66 225 oddfire motor with D44 rear and D30 up front but is currently not installed. Currently T90 transmission but hav 420 I’m rebuilding to put on a V8 when time comes.
     
  7. Jul 8, 2022
    Keys5a

    Keys5a Sponsor

    Florida Keys
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    Stock 225 gearing was 3.73 standard, and 4.88 optional, so anything in between will be OK. 3.73 gearing will be more road oriented, and the steeper gears will favor off-road/trails. The width of your tire make little to no difference in gearing, but diameter/height does. A future V8 will have more torque than a 225 V6, so will pull the 3.73 gears more easily, as noted by Fireball.
    As mentioned. High pinion is found on much later vehicles and as Tim noted, the pinion casting is higher than the axle centerline.
    -Donny
     
  8. Jul 9, 2022
    y2grey

    y2grey Member

    Fayetteville NY
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    Sep 18, 2011
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    106
    I run 4.27s behind the 225. It's on 35s with no overdrive.
     
  9. Jul 9, 2022
    Warloch

    Warloch Did you say Flattie??? Staff Member

    Falcon, CO
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    I'm real partial to the 4.88s, but I run an OD on everything as well. Got 33s and 31s on the rigs with them - trannies are SM465 and T18.
     
    y2grey likes this.
  10. Jul 10, 2022
    shaun

    shaun Member

    Lebanon, Ohio
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    Oct 15, 2015
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    Thanks for that info. I like the OD option but if I’m swapping the 3 speed out I don’t know if OD is an option, so I think 3.73 May me my answer. I didn’t know the 225 came stock with 3.73, plethora of info on this site.
    !!!!
     
  11. Jul 11, 2022
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    The overdrive depends on the original Dana 18 transfer case. If you plan to keep that, you can have the overdrive with any transmission that will otherwise fit. The main constraint is the rear driveshaft length. A 5- or 6-speed overdrive transmission, and nearly all automatics, are too long for this chassis without some heroic mods. The truck 4-speeds are popular, but you can go a whole lot of places with the original 3-speeds. Deep axle gears, the original 3-speed, and an overdrive would be a lot of fun, and get you on the road with comparative ease.

    The V6 Jeeps were 3.73 standard, 4.88 optional. The majority of F134s got 5.38s, though 4.27s were available in the latter half(?) of the run. Jeep switched to 3.73 standard and 4.27 optional for the CJs in 1972.
     
  12. Jul 11, 2022
    shaun

    shaun Member

    Lebanon, Ohio
    Joined:
    Oct 15, 2015
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    For the most part I’m sticking with original D18 but swapping to 420 transmission. If I went to original 3.73 gears for the dauntless 225, it may be more favorable for me. Just one less stick I have to worry about and reading that if I have OD in gear too long it may be worn out sooner. I live by a lot of 45-55mph roads, so OD would be in gear a lot I presume. My final jeep will hope to be 5.3L with sm420, d18, 3.73 gears in D30/D44 on 33”
     
    jeeper50 likes this.
  13. Jul 14, 2022
    SeaJ

    SeaJ New Member

    Seattle
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    I'd also recommend the OD. Super easy install. My '69 is the stock 225, T-14, D-18 w/OD and 4.88's. I'm running Deestone D503 - 7.50x-16's which are about 31.5" tall. It pretty much lives on the street and I think the gearing is perfect. It'll do 60-65 no problem. I am planning a T-18 swap in the near future though, just to get a lower 1st and replace the failing T-14.
     
  14. Jul 14, 2022
    duffer

    duffer Rodent Power

    Bozeman, MT
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    The Warn OD's are rated at 300 ft-lbs and I suspect that held for Saturn. IMO, the Warns will take a good bit more than that if you drive reasonably. Mine stayed alive behind both a not-so-mild 350 and a 381 for better than 3 decades. It is still in the 3B but I suspect it will be leaving soon as jpet's D18 gears will not work with it and the current sbc will be making almost twice that torque rating. I ran that with 4.10 gears and the sbc's were just loafing down the road at 75 mph.
     
  15. Jul 16, 2022
    shaun

    shaun Member

    Lebanon, Ohio
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    I may start with a re gear 3.73 and see how it runs with that then May think about OD with a 420 tranny and 18 TC. Along with a 5.3 because of fuel injection and more available parts. But regear is a definite I think for me. I’d like cruise speed at 65 but not for more than 20 min just to get to work and back.
     
  16. Jul 17, 2022
    Keys5a

    Keys5a Sponsor

    Florida Keys
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    If you re-gear with 3.73 gears, an overdrive probably won’t be needed. You should be fine out on the road with 31” or larger tires. An overdrive is a benefit with much lower gears, like 4.88s. I ran an overdrive for a while with 4.27 gears, and it was not really needed.
    -Donny
     
    shaun likes this.
  17. Jul 18, 2022
    Warloch

    Warloch Did you say Flattie??? Staff Member

    Falcon, CO
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    Yup - flipping my OD on the 4.88s is like an axle swap to 3.80 (about 22% for the 4 gear Warn Cluster OD) gears. Durability, with proper maintenance (mostly oil levels and cleaning) I've run them since the 80s when they first came out. The Kenne Bell engine in the '51 was built for the Pikes Peak Hill Climb, and while the cam has been tamed back, it is still a lot stronger than any other 225 or 231s I've been around. The OD does just fine in it.
     
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  18. Jul 18, 2022
    duffer

    duffer Rodent Power

    Bozeman, MT
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    Those arrived at least a decade earlier. I bought my Warn OD for the CJ 5 in 71. It was a nice even $200 plus $5.00 shipping-still have the receipt. The one for my 3B was installed in 1975. I've had no problems with either but there are a couple of 3 decades+ old Warn rebuild kits still hanging on the shop wall.
     
  19. Jul 19, 2022
    Warloch

    Warloch Did you say Flattie??? Staff Member

    Falcon, CO
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    Your right - I looked at the original tag I still have for it and the adapter I bought from Novak... in '78 For some reason I was hoping I wasn't that old I guess :confused:
     
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