lift axle

[butterfly610]

If driving a straight truck with lift axle registered for 54,000 pounds, what would the legal axle weights be?

 

[zorry]

Here's your first guess: the pair of rear axles, if closely spaced, would be rated at 34,000 lbs. This would be with 8 tires, or 4 wide based singles. Your front axle would be rated at whatever axle and tires are built for. Typically 12,000 # on a class 7 or 8 truck. Sometimes 10,000# on an M2 type truck. Add it all together and you are probably good only to 46,000 #. It doesn't matter what size plate you buy. There should be a tag on front axle stating it's rating. This info also is usually on a sticker on driver's door jamb .

 

[zorry]

If you have 4 axles, ratings will vary state to state , by tire size and spacing. A truckers atlas describes this in detail.

 

[butterfly610]

I was thinking 34,000. Thanks. So it doesn't matter how much the rear and lift axles weigh individually? It's just they can't be over the 34,000? Never used them, so just curious.

 

[Doggie Daddy]

46,000 is correct, so if you are paying more to have it registered at 54,000, it would be wise to drop back to the 46,000 limit.

 

[Rocketman]

Where does the 2290 heavy highway use tax start? Seems like either 52k or 54k. You definitely want to avoid that by staying under it with the tags unless you can legally scale that much and have a real need for the capacity.

Just for verification... you have a single axle truck with a lift axle correct? 3 axles total? That would 46k lbs max most likely.

 

[zorry]

A single rear axle,dual wheels, carries 20,000#. a pair of those , usually spaced 54" center to center can carry 34,000#. A lift axle with 2 tires,may only be good for 12,000# additional . 55,000# plus requires paying an annual tax on an IRS form #2290. This I imagine is why the truck is plated for 54,000# . You're wasting money plating at 54,000 # if truck can only haul 46,000#.

 

[zorry]

I pulled into a scale and got inspected. A steer axle slack adjuster went bad. One brake out of adjustment. IF I had lift axle up, 25% of brakes ( 1 out of 4 ) would have been bad. I would have been placed O/S. I always leave my lift axle down. with 1/6 th of my brakes bad I got a fix-it ticket and continued on. The extra braking, improved ride and stability, to me makes a lift axle a false economy in expediting. Yes, it does have a fuel savings. OK for a linehaul operation with volume of miles. We aren't about volume. We're about quality.

 

[greg334]

If driving a straight truck with lift axle registered for 54,000 pounds, what would the legal axle weights be?

Straight truck with how many Axles it has?

 

[layoutshooter]

I could register at 54 if I wanted too, I don't want that. I have no need for it. I am registered at 48. I can legally scale 18. I have never got even close to that weight, and likely never will. No need to pay that extra tax.

 

[butterfly610]

It is a straight truck with 3 axles. The lift axle has two wheels, so rear is 8 wheels. My question is....if it can weigh 34,000 in the rear it doesn't matter how the weight is distributed on the rear and lift axles as long as in combination it is at or under 34,000 correct? This is not our truck, so i don't pay for registration, I'm just curious about the loading. But good to know for the day we buy our own, as far as the playing thing.

 

[greg334]

It is a straight truck with 3 axles. The lift axle has two wheels, so rear is 8 wheels.

Thanks, so then where is the lift axle located?

My question is....if it can weigh 34,000 in the rear it doesn't matter how the weight is distributed on the rear and lift axles as long as in combination it is at or under 34,000 correct?

yes. You still have to be careful of the weight on the front axle. The reason for my above question - if the lift axle is near the other ones, you "can" put a too much weight on the front axles but if the lift axle is towards the front of the truck, then you can balance it out.

This is not our truck, so i don't pay for registration, I'm just curious about the loading. But good to know for the day we buy our own, as far as the playing thing.

Yep them 2290s and the plates are a pain.

 

[Rocketman]

I am going to assume that the drive and lift axle are spaced at the traditional spacing (would look similiar to a tractor trailer tandem drive axle spacing with app. 6-8" between the tires). Also assuming that you have a 12,000# steer axle.

I know that you can't go over 20,000# on either axle. What I don't know is if you could carry 20,000# on your drive and 14,000# on the lift. I have done exactly that without getting bothered, but that does not mean it is correct.

I'm sure you know, but just so you don't forget. When the lift axle is up, you can still carry 20,000# on the drive + 12,000# on the steer axle for 32,000# total.

One tricky thing you have to watch for on a lift axle. Make sure that you load the truck so that the weight can be effected by the lift axle. My lift axle was in front of the drive axle (nothing to do with the tricky part..just noting where it was located). I have seen the time when I had so much weight toward the back of the truck that when I dropped the lift axle basicly all I did was take weight off the steer. I had to have it re-loaded.

Lift axles can be tricky. Mine was not set up at the traditional spacing either which made it a little trickier. The added capacity will get you loads when others are sitting and if your a good negotiator, they can pay quite a bit better at times.