New to Mack dump trucks and could use insight pls

[TAV]

I am used to driving tractor trailers with an 80,000lb max; however now, I am trying to help family with a couple of dump trucks.  We have a 1996 Mack model CL713 and a 1997 Mack model RD690S.  On the side of the CL713 it says an ID number, then GW 57,500 then NW 32,040.  On the RD690S it only says GVW 70,000.  They both have a 'trailing' or liftable axle, but the owner wants them removed to max out payload weight and in GA where we will be traveling I don't believe they are necessary.  What I am trying to find out is what is the GVWR for these trucks to be legal?  I am just not sure how to understand the numbers on the sides...70K lbs seems like a lot of weight for such a short truck and the aluminum box truck has the GW and NW and I'm not even sure I know what that means.  Please help...thanks in advance!

Leslee 

[tjc transport]

GW, and GVW are the weights the trucks are registered for. 

NW is net weight, which is what the truck weighs empty. 

[TAV]

Thank you TJC Transport.

[MackTech]

I'm not sure when it changed but when a truck is made at the factory they put the net weight of the truck which is the weight of the truck without a driver, without a body, with minimal fuel (maybe 17 gallons).

 

Removing the lift axles will reduce weight, but you need to check where they will be used that there aren't axle weight limits you may be affecting with removing the lift axles.  At the plant we refer to the lift axles in front of the first drive axle as a pusher axle, and the lift axle behind the last drive axle as a tag axle.

[OldRedMack]

GA is 64,000 lb gross on 3 axles, lift axles only mean you can haul less weight in GA. Also even though it's 64k gross, if you have a lift axle on the truck you have to use it. So you get less payload with more wear and tare.

[JoeH]

In PA those trucks are good for 73,280. Tandem axles are only good for about 58k I believe in PA.  What you're able to get on the truck depends on the axle weight ratings.  Example, steer is probably good for 18k, and the drive tandem is probably good for 44k.  Combined you're looking at a legal weight of 62k loaded without that lift axle, depending on what your state regulations are. In PA the lift axle only needs to be down if you're over 58k or the weight rating of any particular axle.

[JoeH]

Reason to keep that lift axle: it's an extra set of brakes.