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!0 bolt / 14 bolt swap

Discussion in 'The Garage' started by gotchevys?, Oct 16, 2005.

  1. gotchevys?

    gotchevys? Registered Member

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    I own an 89 sub with 33s and 3.08s. I was considering swapping out the gears to 4.11s. The Sub is got to see serious trail use. Its main purpose is for transportation and once the 4.11s are installed it will be used occasionally as a tow rig. I will be towing probably 6,500 to 7,000 pounds max. Most of the time it will be 5,000 pounds or less, most of the time less. Also keep in mind that I will not be towing with it daily or even weekly just on occasion. Now for my question. Should I swap the gears in the 10 bolts or opt for 12 or 14 bolts that already have 4.11s. The main problem I have with this is that you never really now what you are getting when you buy used from somebody else. I am looking for an inexpensive solution. I purchased a 12 bolt with 3.73s used and insatlled it in my 89 jimmy and It turned out to be junk. If I install 4.11s in my 10 bolts I know what I have. It needs to be reliable as it may be driven fairly long distances. Also if I go with 14 bolts, what other modifications and changes need to be made besides the wheels. The Sub runs, rides, and handles like a dream. I hate to change anyting with it. Why mess with a good thing. But the gears are way to high. I know this is a lot of info but Thank you in advance for any input you may have. :burb: :usaflag:
     
  2. ryan22re

    ryan22re 1/2 ton status

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    replacing a 10 bolt with a 12 bolt is really not that much of an upgrade. i really think your best be would be a 4.11 14ff and an 8 lug conversion for the front with a matching gearset.

    not only will you get a stronger rear axle, you would get an upgrade in braking. lets face it, a 6000lb sub towing 7000 lbs needs alot of braking power.

    just make sure to pull the cover and inspect the inside of the diff if you dont know who you are dealing with. hell, pull the thing apart and inspect all the bearings before you buy it.

    ryan
     
  3. SUBFAN

    SUBFAN 1/2 ton status

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    Towing that much weight around and having 33's, I would look around for some 4.56's....I wouldn't wanna tow that much around in my 'Burb w/31's and 3.73's....
     
  4. AZPiNsTrIpEd

    AZPiNsTrIpEd 1/2 ton status

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    Definately go with the 14 bolt, 8lug swap. The rear is a huge upgrade in strength and reliability and like ryan22re said it would brake better too. I did the swap in my blazer and noticed a big difference in braking, and the 14 bolt should bolt right up :D
     
  5. 89GMCSuburban

    89GMCSuburban 1/2 ton status

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    I ran the burb on 33's to get here to CO. If you are gonna keep it in D for towing (as you should), 4.10's would be good for you. With 36's, I wish I'd put 4.56 in it when I had the chance, but I'm going 4.88 or 5.13 here sometime. But it all depends on your towing style, if you use OD while towing, or you like to go fast, or slow. These will help determine what ratio you want.
     
  6. fatbob

    fatbob 1/2 ton status

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    :thumb: You need to define your goals first, before you can get any good advise. :confused: Everybody wants those gears that are good for [serious trail use]so performance not fuel economy,[main purpose is for transportation]so fuel economy not performance,[The Sub runs, rides, and handles like a dream]. You already have decent gears if its MAIN purpose is transportation, and not towing or wheeling. :wink1: Have you noticed some guys are willing to give up some gas mileage for more performance, then when gas prices go up, they post questions on how to grt better mileage, or they need to sell it and get a more economical car. :doah: If you keep your eyes open you could probably buy a beater with the right gears for the same as you would spend on regearing or putting different axles on yours. I have a 3/4 ton with 33's and 4.10's and it really sucks up the gas on the highway if I go over 55 MPH, but it is more set up for towing, not a daily driver :thumb:
     
  7. gotchevys?

    gotchevys? Registered Member

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    10 bolt /14 bolt swap

    The MAIN use of the sub is transportation, but I do need to do some towing with it. It is currently geared 3.08. The other day I was towing about 5000 pounds estimated (dual axle lo boy flatbed trailer loaded with an 89 jeep cherokee) it was all the sub would do to maintain 65 in drive on the interstate. The Sub usually run about 190 degrees and when the temp reached about 210 I got of the interstate and took normal roads so I would not have to push it to hard. My dad purchased the sub new in 89 and he used to pull almost 10,000 pounds with it with the stock 235/75/15s. The truck will not be used for off roading so I belive that 4.11s will be my best bet in order to give me more pulling power and keeping the rpms down on the highway. Gas milelage is not a big concern. If it was I would not own a suburban.:burb: :usaflag:
     
  8. 4xcrazy

    4xcrazy 3/4 ton status

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    YEAH, you better put in a 14bolt and a Dana 60 for a transportating tow rig :rolleyes:


    you CAN tow good enough with the 10 bolt, and even with 3.73's,,,i have done it before with no issues, alittle slow up the hills, but what do you expect towing something that weights almost as much as the tow rig,,,


    if you do not see any serious trail use, just upgrade the gears,,,everybody on here is all about the 14b and d60 or 8 lug conversion,,,,to me it doesn't sound like you need to go that route.

    and are you sure they are 3.08's ???


    i thought they went with either 3.73 or the 3.42's in those years,,,i know mine had 3.42 when i got it..
     
  9. 3rdshiftdesign

    3rdshiftdesign 1/2 ton status

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    towing usually isn't the issue, it's stopping it when you need to in a safe manner.

    if you tow frequently, then i'd consider upgrading axles for braking purposes, and to get 4.10's easily.
     
  10. 4xcrazy

    4xcrazy 3/4 ton status

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    well seeing as he said it will be used as an occasional tow rig, i still don't see the reasoning for bigger axles for a mostly street driven daily driver,,,you are towing, you should be aware that the stopping distance is going to be greater,,,all common sense...
     
  11. 86sierra

    86sierra Registered Member

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    Just curious, what is the weight difference between a 14-bolt and a 10-bolt rear end?
     

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