1. Registration trouble? Please use the "Contact Us" link at the bottom right corner of the page and your issue will be resolved.
    Dismiss Notice

Manual Transmission Advice? Choices, Choices.

Discussion in 'Jeepster Commando and Commando Tech' started by Elijah Oldham, Nov 12, 2018.

  1. Nov 12, 2018
    Elijah Oldham

    Elijah Oldham New Member

    Kentucky
    Joined:
    Jul 15, 2018
    Messages:
    21
    After some consideration and research, I am thinking about putting a manual tranny in my 66' commando. Leaning towards a 5 speed with overdrive. Sporting the Buick 225 dauntless and a Dana 20. I'm looking for something easily adaptable, this is just a daily driver on 33" tires. What would you gentlemen propose? NV4500? AX15? NV3550? T5? Something else?

    Thanks!
    Elijah
     
  2. Nov 12, 2018
    TIm E

    TIm E Aggressively average

    NW Arkansas
    Joined:
    Mar 2, 2017
    Messages:
    683
    dnb71R2 and Elijah Oldham like this.
  3. Nov 12, 2018
    ITLKSEZ

    ITLKSEZ Hope for the best, prepare for the worst

    Liberty Lake, WA
    Joined:
    Aug 13, 2015
    Messages:
    6,656
    You didn't give us much to work with...

    What trans is in it now?
    What's the current axle gearing?
    Why a 5-spd?

    IMO, the overdrive coupled with the 33s will be unusable if you have axle gearing (numerically) lower than 4:88s.
     
    timgr and FinoCJ like this.
  4. Nov 12, 2018
    FinoCJ

    FinoCJ 1970 CJ5 Staff Member

    Bozeman, MT
    Joined:
    Jul 18, 2013
    Messages:
    5,593
    Agree with ITLKSEZ here - If you have 3.73s, and 33s, I would go with TH400. If you have 4.88s, then an overdrive will be nice. So what about a 700r4 OD 4speed?
     
    dnb71R2 and Elijah Oldham like this.
  5. Nov 12, 2018
    ITLKSEZ

    ITLKSEZ Hope for the best, prepare for the worst

    Liberty Lake, WA
    Joined:
    Aug 13, 2015
    Messages:
    6,656
    He's looking to go with a manual. :contract::)
     
  6. Nov 12, 2018
    FinoCJ

    FinoCJ 1970 CJ5 Staff Member

    Bozeman, MT
    Joined:
    Jul 18, 2013
    Messages:
    5,593
    Damn - for some reason I read that the other way around...thanks...
     
  7. Nov 13, 2018
    Elijah Oldham

    Elijah Oldham New Member

    Kentucky
    Joined:
    Jul 15, 2018
    Messages:
    21
    My bad. Axles are 3.73s. DANA 27AF front and DANA 44 Rear. I'm looking to swap the front with a DANA 30 with discs. Current transmission is a T14. I initially wanted to go with a 700r4 but I'm having second thoughts, lots of choices. If I go automatic I want the 700r4. But I thought id consider a 5 speed overdrive. For the purpose of the overdrive and because it might be an easier installation. This is going to be a daily driver, I'm in the middle of a frame of restoration. I happen to have a SM465 4 speed I considered using, but I'm kinda set on having overdrive. Of course I'm happy to hear input from some persons more seasoned than myself.
     
  8. Nov 13, 2018
    heavychevy

    heavychevy Sponsor

    Danielsville georgia
    Joined:
    Sep 7, 2008
    Messages:
    181
    The new 5 speed that mahindra uses in their roxor might be an option
     
    Elijah Oldham likes this.
  9. Nov 13, 2018
    ITLKSEZ

    ITLKSEZ Hope for the best, prepare for the worst

    Liberty Lake, WA
    Joined:
    Aug 13, 2015
    Messages:
    6,656
    Yeah, like I stated before, an overdrive with 3.73s on 33s will be wasted money. The OD will take you up into speeds that the 225 won't have the power to hold at the rpm you'd be pulling. Fuel efficiency will be nil because you'd probably be below the optimum torque curve. I'm not sure I see the motive besides the coolness factor? (Unless you plan on re-gearing the axles.) And I'm a little lost on the 'ease of installation' benefit?

    If you're keeping the 3.73s, you'd get a greater (and more practical) gearing spread out of an SM465 than any of the 5-speeds you listed, and at half the cost.

    Just my $.02
     
  10. Nov 18, 2018
    Keys5a

    Keys5a Sponsor

    Florida Keys
    Joined:
    Jan 23, 2014
    Messages:
    4,170
    I agree that a transmission with a 1:1 (non-overdrive) top gear works very well with 3.73 gears. The 33" tires are on the outside range of running a 1:1, in my opinion. Many 5th gear ratios are in the .82 to .72 (overdrive) ratio. This would prove too tall unless you had a high torque engine like a 383 stroker.
    -Donny
     
    Elijah Oldham likes this.
  11. Nov 19, 2018
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
    Joined:
    Aug 10, 2003
    Messages:
    23,596
    If you want a manual transmission, all the truck 4-speeds are a pain in traffic. They are strong, but have heavy gears and slow shifting. Why do you want to swap? Most pick the truck 4-speeds (SM465, T-18, etc.) for that super-low 1st gear, wanting to get that for trail use. The T-14 is an easy shifter and quite ok for daily driving and most trails. If you want something a little stronger, the T-15 is strong enough for V8 power, shifts pretty much like the T-14, and the adapter is inexpensive. There are also car 4-speeds that could be adapted.

    If you want more capability on the trial, you could add Tera gears to your transfer case, or selectable lockers front and rear.
     
    Last edited: Nov 19, 2018
    Elijah Oldham likes this.
  12. Nov 19, 2018
    Elijah Oldham

    Elijah Oldham New Member

    Kentucky
    Joined:
    Jul 15, 2018
    Messages:
    21
    Well now I'm going to have to do some thinking again. Would y'all recommend swapping out my ring and pinions for something like a 4.11 or 4.56? Im going through a full frame off with this jeepster and im just trying to figure out a good setup. Im NOT worried about offroading. it might find itself offroad on my farm or on some bad gravel roads but thats about it. So I dont want a granny gear tranny, nor does it really need to be that heavy duty. I wanted to originally put a 700r4 into it for an automatic with OD. But the Jeepster is already a manual and adapters for the automatic to the 225 and DANA 20 are not the cheapest. I only wanted a 5 speed for the OD aspect as well. Can someone explain the effect the tires have on overdrive? Do the larger tires create an overdrive effect as is? Whats the cruising RPM of a 225? If an overdrive is useless Im back to a TH400 or a manual. Maybe a T18 with a 4.02 low gear, or a Tremec T176, or stick with the T14 I already have...
    Thanks to all you guys for sharing some info with me.

    As a side note, the oil pickup for my 225 has a hole ate through one side of it. Would early 231 pickups be the same? Ive fould a MELLING 20-IS1 that looks the same. Is a 225's the same oil pickup used in Buick 300, 340, and 350's?
     
  13. Nov 19, 2018
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
    Joined:
    Aug 10, 2003
    Messages:
    23,596
    The T-176 would be a good choice, but it has a New Process transfer case pattern that won't work with your existing Dana 20. You could instead adapt a Ford Top Loader passenger car 4-speed to the Dana 20, and use the T-176 shift top (same transmission). The top shifter is a nice feature for a Jeep.

    If you want to regear your axles, both the AX-15 and NV3550 5-speeds would be a good choice. They also have the New Process pattern and would have to be adapted at both ends... or use a different transfer case.

    Yes, the height of your tires matters. The taller the tire, the larger its circumference. One turn of the tire travels farther with a taller tire, having the same effect as a gear change.

    For what you describe, there's nothing wrong with the T-14. Many happy owners put thousands of miles on these Jeeps using the factory drivetrain. What rear axle do you have? Do you have a factory limited slip differential?
     
    Elijah Oldham and ITLKSEZ like this.
  14. Nov 19, 2018
    Elijah Oldham

    Elijah Oldham New Member

    Kentucky
    Joined:
    Jul 15, 2018
    Messages:
    21
    Rear has been swapped for a 3.73 Dana 44 positive traction I'm pretty sure.
     
  15. Nov 19, 2018
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
    Joined:
    Aug 10, 2003
    Messages:
    23,596
    Some of these Jeepsters had a Dana 30 rear axle. A 44 could be either a flanged axle or tapered (nutted) axle. Each came with a different type of LSD.
     
  16. Nov 19, 2018
    Elijah Oldham

    Elijah Oldham New Member

    Kentucky
    Joined:
    Jul 15, 2018
    Messages:
    21
    Its a flanged 44
     
New Posts