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Question #2... gears? or doubler?

Discussion in 'The Garage' started by Thumper, Nov 9, 2003.

  1. Thumper

    Thumper 1/2 ton status

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    Ok, does anyone on here run 4:10s with a doubler and 38 or 39s? I have had the 35s and 4:56s for a long time now. The crawl ratio with the stick tranny was great, but I suffered on the highway... running 3000rpm at 55-60 mph... gas mileage sucked. Also, on the trails, in 4hi, I was constantly shifting between 1st and 2nd (1st, not granny), granny for the tough stuff, and 4 lo for the rocks etc. Worked good, and didnt know any different... till now.

    Todays run was with the 38s, and the 4:10s in the diffs (cant afford 4:56s for the 14FF yet). Around town, she is pretty doggy, not a street racer at all. We head out the highway, Im leading three other trucks. I get a CB call... 'Mike slow down! I dont run that fast on the roads!' I look down, Im running at 2000rpm, speedo reads 80 kph (maybe 45-50 mph), I glance at the GPS and it says Im doing between 97-100 kph! The truck isnt even sweating! And the gas guage sure wasnt dropping like it normally did. So... I slow for the Jeep guys /forums/images/graemlins/smile.gif.
    On the trail, I am running in 4hi 1st gear... ALL DAY... the only times I shifted was if we hit a fast stretch I could use 2nd, or a real slow section where I used granny, or a rough crawly section for 4lo. It was amazing. The granny 4lo crawl ratio isnt what it used to be, but the rest of the gear ranges were way more useable.

    Basically, I am seriously thinking about leaving the 4:10s in the diffs, and spending the $$ on a doubler. What are your opinions?
    I am totally reconsidering my whole truck building plan. Up here, gears will cost me about 300.00/ end. Thats 600.00, plus install kits. I wont want to go just to 4:56, I was thinking about 5:13s. Which in a D44, according to some of you guys isnt a good idea. I have the 203 case laying here behind the garage, I have lots of abilityt to make the shifter, the driveshaft will cost a bit, and there is the cost of the doubler kit itself. Maybe its a better idea than swapping to lower gears...

    Need some opinions.
    Thanks
    Mike
     
  2. jms

    jms 1/2 ton status Author

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    Here's the plain numerology:
    Gears: 5.13 vs. 4.10: ~25% change
    Doubler: 3.96 vs 2.6 (or whatever a NP208 reduction is): ~50% change + more choices
    I plan to go D, but not just yet; I need driver upgrades first /forums/images/graemlins/laugh.gif
     
  3. yunit

    yunit 1/2 ton status

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    I think that in your case going with a Doubler would be your best option at this point. Run with the 4.10's for a little while and maybe upgrade to a D60 eventually and then 5.13's.
     
  4. jac6695

    jac6695 1/2 ton status

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    I have 4.10's and a doubler with a TH400 that works great. I think it would be nice to have lower gears, but I honestly do not think I would notice. I am switching to a small block and 4L60 trans and will have a lower crawl ratio and might change my mind. We'll see. James.
     
  5. 70~K5

    70~K5 1/2 ton status

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    Don't change the gears till you get a D60. At some point you're gonna start blowin' up the D44 runnin' 38s on it.
     
  6. 4GUNZ4X4Z

    4GUNZ4X4Z 1/2 ton status

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    Just like what everyone else said. Wait on the gears till you get a 60, meanwhile throw in a doubler.
     
  7. earl87gta

    earl87gta 1/2 ton status

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    I kept the 4:10 gears when I got my D60 and Im planning on running a dubler to make up for it but Im only going to run 38 tires. I think that I will be happy like this. my d44 had 4:10s in it and I got use to it it would get up to 60MPH slow off the start but it got thier.
     

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