I m looking for structure of an us army lance launching battery during 1980s..does anybody have an idea?

Check out FM 6-42, Field Artillery Battalion, Lance October 1984. It should contain the information you require.

There also is DTIC ADA127320 Lance Firing Team Leader's Handbook.

Thank you both..do you know what vehicles were in the battery `s maintenance platoon?

I contacted the Field Artillery Museum at Fort Sill and provided them the number of the TO&E which was included as a reference in the FM 6-42 in Joseph's note.

And the answer is that the Maintenance Section in each Firing Battery was a part of Battery HQ (along with Supply, Mess, etc.), and consisted of 3 vehicles as follows:

1 M35 2 1/2 ton truck with a trailer (almost certainly an M105 1 1/2 ton 2 wheel trailer although that specific information was NOT provided) This vehicle was for parts and tools.

This is SPECULATION on my part, but I would also add the following: First of all, I'd GUESS that this M35 would have been equipped with a winch, but that is a GUESS!
And second, I would also guess, that the unit would have made a field modification to the M35 and built a plywood box into the bed of the truck with a rear door and a removable stair/ladder from the floor to the ground. This is based STRICTLY on my own experience with FA units at the time. The Maint section typically turned the truck into a "workshop" and covered the plywood with OD canvas, and built all sorts of stuff inside to make it a shop. BUT THAT IS A GUESS!!

Vehicle number 2 was an M578 light recovery vehicle. This makes sense as the launcher vehicles were small enough to NOT require an M88 to recover them.

And the third vehicle was a 5 Ton Wrecker to be used to assemble and transload missles if the Loader-Transporter (LT) vehicle was down. Based on the time period (and again this is a guess because I didn't see the TO&E myself directly) this PROBABLY would have been an M816 and again, probably would have been equipped with a winch on the front of the bumper.