axl and spring question

[gto109]

I was talking with my local mechanic the other day and told him about the camper I'm lookin at.  He told me with hauling the 4 wheelers and that camper both I may want to upgrade to a 3/4 or 1 ton Axl and my 3/4 ton rear leaves should be plenty for holding the weight.  should i upgrade my front springs to 3/4 ton from 1/2 ton as well?  What is the difference in the axles other then gears?

[454k30]

Most 3/4 ton and 1-ton came with the 14 bolt full-floating axle.  Some 3/4 ton had the more rare and far less desirable semi-floating 14 bolt.  The full-floating 14 bolt is an incredibly strong axle designed to take the abuse of towing and hauling.  Replacing your 10 or 12 bolt rearend with one will certainly eliminate that weak link.  You would want to find one that has the same gear ratio as your front axle, and that may be a problem.  The gear ratios you are going to find in the junk yard are proabably going to be in the 4.10 or 4.56 range.  Your truck is probably set up with something like 3.42 or 3.73 gearing; that is only a guess based on your drivetrain configuration.  As for springs, sure you can upgrade those as well but you really don't have to.  Very little weight gets tranferred to the front springs.  Now, you are talking about hauling an incredible amount of weight in a truck with a 305.  Not that it can't be done, but you will be hating that little motor.  I'm very attached to my truck too so I know this will sound harsh, but you should probably go out and find a k20 or k30 that already has all those heavier parts as well as the larger motor to turn it all.     

[gto109]

I can get a 350 for around 300 running here.  I also have a 350 block on the engine stand.

[454k30]

350 would help.

[bake74]

     If you have 1/2 ton axles on your truck now, you would have to change both rear and front axles to maintain the 8 lugs on both.
     I agree with the 305 question, if you are planning on towing a lot with that much weight, then the 350 should be set up for low end power and not high end power, or else it won't be much different than the 305.
     If your budget allows, you will end up thanking yourself if you swap over to 3/4 ton axles, but remember, with bigger component's come bigger repair cost when doing things like brakes.  The next 4wd drive truck I build will be a 3/4 or 1 ton truck, just for the beefiness, and I plan on building it to sell.  People like big, tuff looking trucks.

[rustyMUD]

  Some 3/4 ton had the more rare and far less desirable semi-floating 14 bolt. 

    The semi floating 14 bolt is anything but rare.  It was introduced in 1981 on 3/4 ton trucks and since then can be found on anything from light duty 3/4 tons, heavy duty half tons(newer 1500HD) and even the Hummer H2.  After 1981 it seems like every 3/4 ton truck had one.  I have two 3/4 tons, both with a GVWR of 8,600 lbs, and both have the semi floating 14 bolt.  Maybe it's just a Michigan thing, but it seems like every eighties squarebody 3/4 ton has this axle around here.  I've seen only a handful of 3/4 tons with the full floaters after 81.  Now before 81, then yes the full floaters are everywhere.

The semi float 14 is fine for heavy use, there's a reason that GM put them on trucks with a GVWR of 8,600 lbs.  I've used my 81 3/4 ton for hauling a payload of around 3,000 lbs on a regular basis.  The semi floating 14 bolt rear axle is original and holding up just fine.  Some added benefits of the semi floating 14 bolt are that it weighs less than the full floater and also has slightly better ground clearance.  In terms of strength, they'll both hold up fine to hauling a camper and four wheelers.  I know of two people running welded 14 bolt semi floaters with 38.5 and 40 inch tires.  They don't go easy on them, and so far the rear axles are doing just fine.   

   To the OP, do as bake74 said and replace both front and rear axles.  Check Craigslist, people frequently sell sets of axles in the "auto parts" section.  Although it sounds obvious, make sure that both axles have matching gear ratios.

[Blazin]

Semi float 14 bolts are not much different than your half ton rear axle. They use C clips to retain the axles, they have a single wheel bearing that is fit inside the outer end of the axle tube. The axle itself not only drives the wheel but also carries all the weight of the truck, and what ever load it might carry.

Full floating 14 bolts how ever run two wheel bearings per side. They ride over the spindleinside the hub. The axles only job is to drive the wheel. The weight of the truck, and its load rides on the axle housing, not the axle itself.

As as front springs go if your going to change the rears to heavier, you should change the front too. Weak front springs can cause more weight to be transferred to the front. this will result in less on the rear wheels, could result in loss of drive traction or cornering traction. Could cause the rear to try and catch up with the front easier than if there was more weight on the rear wheels.
 
As long as you can find a matching rear gear to your front end you don't need to change it. You will just have to change from the knuckle out. The backing plate, spindle, wheel bearings, rotors, and calipers to the 3/4 ton 8 lug set up. Both Danna 44s and 10 bolts where made in 6 and 8 lug. the axle housing, gears, and axle shafts are the same either way.

[gto109]

There is a guy locally selling both axls out of a 3/4 ton for $250 from the picture it looks like springs are included.  I sent him an email today now its time to play the waiting game

[bake74]

There is a guy locally selling both axls out of a 3/4 ton for $250 from the picture it looks like springs are included.  I sent him an email today now its time to play the waiting game

     That right there is a great deal if it comes with springs, even if it doesn't have the gear set you want.  It would be worth the money to buy them and change gears and still be ahead of the game as far as money goes.  Great find.

[gto109]

This is the add I found.  http://classifieds.pennswoods.net/classifieds/viewad.cgi?adindex=1527213  I already emailed him now its the waiting game.

[gto109]

I'm going to look at them tomarrow.  he said the rear axl is a 14 bolt and the front is a 10 bolt.  I have a 10 bolt in mine now would it be easier to just change the gears, spring, and make it an 8 lug set up?

[bake74]

I'm going to look at them tomarrow.  he said the rear Axel is a 14 bolt and the front is a 10 bolt.  I have a 10 bolt in mine now would it be easier to just change the gears, spring, and make it an 8 lug set up?

     In my opinion, it would be easier to swap out the axle, even it you need to fix some of the steering componets.

[gto109]

I guess they was going to use them for a buggie of some sort and changed there mind.  So everything in the picture for the axles is included.

[thirsty]

He said in the add "rear locker sold as is". You should ask him what he meant by that. I hope it isn't broken. I would hate to see you buy something messed up.

[gto109]

I missed that I'll have to ask