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Changing the rear in a 4x4

Discussion in 'Chevy Trucks' started by Crazy_Eddie, Mar 31, 2003.

  1. Crazy_Eddie

    Crazy_Eddie Member
    Messages: 38

    I've been lurking for a little while and have come to learn that you fellas know what your talking about..

    I recently bought a '94 K1500 4x4 w/ a rebuilt 350 and 3.42 rear. I bought the truck to pull my boat, but have found it doesn't pull as well as I'd like it. I was thinking about changing the gearing to 3.73.
    I'm pretty good with a wrench, but yanking the T-case is beyond me. About how much money am I looking to spend if I have someone do it?

    Thanks..
     
  2. Chuck Smith

    Chuck Smith 2000 Club Member
    from NJ
    Messages: 2,317

    Eddie,

    First of all, to change the axle gears, you do not need to remove the T case. Changing the gears (IMO) is best left to a pro. Going from 3.42 to 3.73 might not give you that much more power when towing. Remember, the better the truck will pull, the lower your fuel mileage will be. You'd notice a BIG difference if you swapped in a set of 4.11 gears, and you'd notice your fuel gauge dropping faster too. :)

    Since the truck is a 94, you would want to rebuild the rear axle along with changing the gears. I don't know how many miles you have on the truck, but if you are swapping gears, you may as well have all the bearings replaced too.

    Since it's 4wd, you also would need to change the gears in the front differential as well. Again, the T case would not have to come out to do it. The front and rear ratios need to match.

    If I was to take it to a shop around here, I would expect to pay between $700 & $1000, not including the gear sets, per axle.

    Welcome to PlowSite :waving:

    ~Chuck
     
  3. wyldman

    wyldman Member
    Messages: 3,265

    Chuck's right on the gear change.It won't help that much,and can get costly for front and rear gearsets installed.

    You may want to look into some other mods,like increasing the power output.An intake system,good exhaust and a chip,might just help and be a little easier on the wallet.
     
    Last edited: Mar 31, 2003
  4. John DiMartino

    John DiMartino PlowSite.com Veteran
    Messages: 2,154

    Eddie, I feel for you, I had the same combination in an 89 Chevy,it couldnt pull car on a trailer worth a darn. If you swap go with 4.10. You might try searching you local salvage yards as welll, you may be able to buy a complete rear axle with warranty for about 5-600,then swap them in about 1-2 hrs. To be honest if the truck isnt meeting your expectations by a long shot,it never will,only a big block,or diesel will pull that thing like it isnt even there.i tried headers,chip,exhaust,TBI spacers,and different iginitions,they werent worth the $ ,and made truck loud when towing.I finally bought a Cummins diesel,problem solved.
     
  5. nben

    nben Senior Member
    Messages: 101

    I have 4.10's in my current truck, had 3.42's in my last one and my father has 3.73's in his truck. I've tried them all and the 4.10's are better than 3.73's. Fuel mileage isn't really any different (between 4.10's and 3.73's) either. We used to have a 1 ton with 4.56's, but it was horrible on the highway even with overdrive. So IF you decide to do the swap, 4.10's all the way. Also may be a good time to think about a locker in the rear if you don't already have one. I think that John is right on the money with the salvage yard swap if you can find a donor. Good luck.:D
     
  6. Crazy_Eddie

    Crazy_Eddie Member
    Messages: 38

    Thanks for the replies.. If I do the switch I'll go with the 4.10s...

    Thanks
    -e