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Gear Vendors - How many gears do I have NOW?

Discussion in '1969-1972 K5 Blazer | Truck | Suburban' started by Greg72, Aug 8, 2001.

  1. Greg72

    Greg72 "Might As Well..." Staff Member Super Moderator

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    I've been reading up a little on the Gear Vendors Under/Overdrive unit. This is the 2WD only version (connects after the transfer case to the rear driveshaft only). It seems like an interesting way to get some better highway RPM's without doing a transmission swap.

    Here's the question for those of you that know:

    Their website claims the unit will add an overdrive to each gear from 2nd on up (1st is too low to work with OD). So if I add this to my existing TH350....it would seem that I'd have 1st, 2nd, 2nd OD, 3rd, 3rd OD ....effectively a 5-speed transmission when driving on the street.

    Is this really how it works, or are there limitations to the way it shifts?

    If from a dead stop I was to just "floor it" what would happen? (I mean after all the tire smoke! [​IMG]) Would it go through all 5 gears in the order listed above, or would the shifts be different because it's full throttle?

    There seems to be a solenoid button and and ECU as part of this package too. How much of this shifting can be automated, and how much will I have to "actively" remember? (Like disabling the OD before shifting into 4WD so that the driveshafts don't spin at different speeds and scatter all my driveline parts!!!! [​IMG]

    Any input?

    -Greg72
     
  2. arq

    arq 1/2 ton status

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    i was going that way, but 2 people told me that they "blow" the hydralics when you hit reverse. also they tend to leak and parts are hard to find(germany). that's if it's the same gearvendors that you are talking about. both suggested going with the th700r.

    hope this makes sense,

    ARQ.



    1-72 4x4 CST Blazer
    2-71 4x4 CST Blazer
     
  3. Greg72

    Greg72 "Might As Well..." Staff Member Super Moderator

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    Arq,

    The one's I was thinking of are in El Cajon, CA the URL is: <a target="_blank" href=http://www.gearvendors.com/>http://www.gearvendors.com/</a>

    Is that the one you were thinking of.....?

    -Greg72
     
  4. 71RestoRod

    71RestoRod 1/2 ton status

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    Greg,

    I too looked into the Gear Vendors OD. That is the way it works! It will shift at full throttle, and you lock it out in 4WD. Folks I talked to claimed it to be bulletproof. I saw them installed in RVs w/ big blocks, which seems to be the favored application.

    Trouble was, it was more expensive than the 700R4 swap and I didn't like OD working on the back end of the t-case only. They're actually pretty long too which could get you into CV mods with your lift.

    I know what you're saying w/ the gear splitting... my '49 Willys wagon has a 25% OD on it, and it's a real kick to run through all the gears... takes talent to work two shifters at the same time. With the 4:88s I can always find the perfect power combo on the mountain highways and trails around here.. and can still point the spedo at the "P" of MPH. Nothing beats split gears for pulling hills and trailers.

    My first vehicle, at age 15 (many moons ago), was a '49 Willys 4x4 pickup truck. Bought it for $100 and had it towed home. It had a Y-block 292 F*rd engine conversion and a Studabaker overdrive hanging on the rear yolk of the transfer case (2WD style) that I've since learned was an option on some of the old Willys. You had to pull a freewheel cable and flip a switch to engage it. I never had a problem with it freaking out in 4WD... It just wouldn't engage if I was in 4WD.

    For the '71, I ended up having a custom 4L60 and torque converter built to my specs by a local shop. This thing should be way beefier than the TH350 and it was still less $$ then the Gear Vendors route. Once I get it all together, I'll let you know if I can achieve a spontaneous disassembly. I do plan on trying...
     
  5. Greg72

    Greg72 "Might As Well..." Staff Member Super Moderator

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    RestoRod,

    If you've got transmissions going into the beast, it sounds like the restoration project is coming along really well! Do you have any more pictures to share with us?

    Have you decided on a final paint/interior color scheme?

    -Greg72
     
  6. JungleBoy

    JungleBoy 1/2 ton status

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    I think, as well, that the 4L60 is a great swap for a TH350, but, it is weaker, not stronger, than the TH350, owing to the frailty of the OD planetaries. The bulletproof OD combo with reasonably available parts is the TH400/Gear Vendors, which is stronger than the 4L80E.
    JB
     
  7. 71RestoRod

    71RestoRod 1/2 ton status

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    JB,

    You'll get no argument from me! TH400 &amp; GV is a stout combo. I meant that it should be stronger than my TH350! I was hesitant to use even this custom 4L60 setup, but shouldn't be able to shred it with the engine I'm building. I also live at 8500 feet... which robs power to the tune of ~25%. Time will tell.

    Greg,

    Still just a pile of parts... waiting on axles &amp; misc. I'll post the chassis assembly in a few along with some rocker box and tub resto pics. I really need to invest in a digital camera... been waiting for the prices to go down. The other pics were snapped off of video... hence the poor quality.

    Paint? The wife wants it to match her nails... Looks like another classic red resto. To tell you the truth, after all this time, I've grown rather fond of the DP40 look.
     
  8. JungleBoy

    JungleBoy 1/2 ton status

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    I've got a 91 V1500 Sub with the 4L60, 101k and no problems yet. The 4L60E in the 97 K1500 Tahoe puked the OD planetaries at 50k, after being driven by my little schoolteacher wife.
    When I put the TH400/GV setup in the Sub, I will put the 4L60 in the 72 K5, replacing the TH350. It is a good tranny, but not one you can abuse at will.
    Another thought, you may consider a 28k GVW, or better, trans fluid cooler for long life, and use the factory deep pan (about 25 or 30 bucks) and synthetic tranny fluid. I use Mobil 1.
    Good luck
    JB
     
  9. 71RestoRod

    71RestoRod 1/2 ton status

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    JB,
    Thats good advice. I put in the deep pan already. I wanted to go with the new Mag-Hytec pan, but they're back ordered beyond belief. Haven't addressed the cooler yet. I'm toying with some sort of auxiliary setup w/ an integrated electric fan but I can't think of a safe location where it would do any better than crowding a HD cooler in front of the radiator &amp; AC condenser. The last piece of the puzzle is to rig up a trans temp gauge in the blank spot on the gauge cluster. I'm not a big fan of synthetics in the engine, but it seems totally appropriate for the trans. How often do you swap out your trans fluid &amp; filter?
     
  10. JungleBoy

    JungleBoy 1/2 ton status

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    I believe a big plate type cooler (GM, B&amp;M) will fit ok in front of the condenser - new brackets would have to be fabbed. Dunno bout the electric fan in front, I'd rather have the cooler if I had to choose, although someone here, or on the vmag Sub board, just installed a dual fan setup.
    I flush the trans every year (done by a shop, costs about 90 bucks for the flush) and change the filter and fluids, about when I flush out the cooling system.
     

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