40k to 46k upgrade

Will you be allowed or need to have 46K on your drives? Different states have different laws. Here NY will let you go to 107,000lbs on 6 axles, 58,000 on a tri. So if you are 12,000 front, 40,000 drives, 58,000 trailer tri thats 110,000lbs. No need to increase drives.

 

A swap like that is never as easy as it seems. Usually it looks like every thing will go right in then these little differences start a rising. I would want the whole donor truck if possible. You may know but be sure to put a bolt and nut in any left over holes in the frame or weld them up and grind down.

 

Would you not need some sort of certification from the OEM that the truck is now rated for the new weight? Also consider other things like U-joints and frame ratings. The diffs may not be the lowest common denominator.

 

Yes, anytime that you increase a trucks weight capacity you need to get a new sticker or some sort of certification to make it legal in the eyes of the DOT. I am not sure how these are obtained, when I started pricing everything to make my other truck capable of hauling more weight it was cheaper to just go buy a different one.

 

Just a suggestion...if you're going to go to the expense of putting 46k rears under your rig, the only thing I could see that would make it worth it is if the diffs had lockers. Yes, 46k is stronger, but for OSOW purposes, some states are going to give you the same restrictions as to how much weight you can have on the drives.

Quite a few of the Landstar and Daily drivers pull the 2+3+2 trailers with 40 k open diff drives.

 

Realistically, depending on the truck you can buy a 46k cutoff. If your running a Pete with an Air Leaf, the Air Trac (44k/46K) should be a straight bolt on. As far as re-certifying the weight of the tractor that's can be done by any dealer and most of the bigger truck repair shops. Its verifying the upgrades.

 

If you have the space wouldn't it be cheaper and less of a headache to install a drop axle? No need to re-certify, no worrying about matching up gear, axle lifts when not needed.