Axle Swap Question:

Discussion in '6.9L IH & 7.3L IDI Diesels' started by harrietnorth, May 17, 2018 at 1:36 AM.

  1. harrietnorth

    harrietnorth Registered User

    Likes Received:
    Nov 15, 2016
    Buffalo MN
    My truck specifics are in my signature.. sorry for the novel here, I wanted to be complete in my backstory.

    Frank the Tank:
    Frank the Tank (aka Frank) has 4:10s and an LSI. His purpose in life is dump truck Wood hauler, bobcat hauler. etc. General Purpose weekend work beast. He's ugly, but low miles and starts in -20 every winter...

    Next winter his role will evolve into Plow Truck for the homestead.

    Given that the PO never upgraded the springs in the front I feel theres an opportunity for a front axle swap when I transfer the Plow gear from the "DT". adding all that weight is really sag, and push that TTB all over the place.

    DT - Donor Truck
    The DT's body is shot due to rust belt living combined with a Waldock conversion (fender flares and extra moulding). That said, I love the way the truck behaves. The turbo pushes about 7psi, has an R&D IP, injectors, GP's. He came with a plow, and used it this winter. Snapped the LH u-joint which blew out both the inner and outer axle shaft - on the last plow of the season no less. The DT is named as he is, because his Chassis is being donated to the Jessie Duke. Body Swap is eminent.

    Jessie Duke:
    When the chassis swap is done, his role will be 'fun truck', no mudding or rock crawling, just around town driver, hardware store and date night with the wife truck.

    The Plan:
    From a prior post, I acquired a Dana 60 350 Kingpin DRW 4:10 with 350 springs. I am going to swap the spindles onto the Dana 50, then swap the Dana 50 under Frank with the 95a Snowfighter springs and repaired LH axle shaft. Then put that Dana 60 under the DT.

    Double front axle swap.

    My logic is, it solve the problem of Frank's saggy front and sets him up nicely for the added plow truck duties and gets me common rims on all 6.
    It sets up the DT with the Dana 60 for that High-boy stock-ish look...

    The Problem:
    Dam Gears. I love the 3:54's in the DT, from everything I have read on this and other forums, Frank needs to keep his 4:10's, a C6 NA with a load is already slow, 3:54's in Frank would likely be unbearable.

    Shop cost for a gear swap (parts, labor) quoted $1400 just for the D60 move from 4:10 to 3:54. and to do that twice.. uhg. The Dana 50 needs 4:10's.

    Do the Ring and pinion myself. Excuse to buy a few more tools, but at the end of the day, I am not entirely confident in a high precision job, and from my reading seems like more Art then anything when it comes to gear swaps.... stated alternatively, something best left to Pros. The regular shop guys I use won't touch it (sometimes you luck out and hit it the first time, and others you spend 2 days on it)


    Swap the rear ends at the same time, and live with 4:10's on the turbo 'fun truck' and slog around in Frank with 3:54's.

    What sage counsel do you have for my dilemma?

    Finding a Dana 60 with 3:54's seems to be a unicorn in my neck of the woods. Same goes for finding used reverse cut 3:54's (Spicer 700020-1) ring and pinion. I have a spare Dana 50 4:10 ring gear and pinion on the shelf.
  2. u2slow

    u2slow Plan B

    Likes Received:
    May 8, 2007
    Salt Spring Island, BC
    You can probably pickup somebody else's Dana 50 leftovers for $100 or less. Swapping a whole pumpkin is a little more routine than a r&p setup.

    Another cost savings I've found with gears.... bring a mostly empty axle housing to a shop. Then you're not paying for the re & re of the hubs and shafts and hogging their service bay for a day.
  3. austin92

    austin92 Full Access Member

    Likes Received:
    Jul 20, 2016
    Brazil. IN
    I did my first gear set on a 10.25 that’s in my truck now. Also put a truetrac in. I was nervous going in to the project but with my new tools, lots of research, and patients, I’ve put almost 20k miles on my new rear axle. If you’re mechanical inclined, you can do a gear set. Look up my build thread

    Sent from my iPhone using Tapatalk
  4. riotwarrior

    riotwarrior Supporting Member Supporting Member

    Likes Received:
    Sep 19, 2006
    Cawston BC. Canada
    I have 1 3.55 d60 reverse cut gearset ...used in stock.
  5. zebrabeefj40

    zebrabeefj40 Full Access Member

    Likes Received:
    Mar 13, 2010
    Pepperell MA
    While gear swaps are a PITA (I've done a few including a D60 front) it IS a front axle. If you don't get it perfect it will still work fine for the times you need 4x4. I'd worry more about a rear axle gear swap where it's used all the time vs. a front axle where it will see limited use and not full torque by itself.


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