I was intrested in the best method to install my hitch. My last truck was a 2500HD with a factory plastic bed liner. The hitch shop used steel spacers under the bracket to fit in the groves of liner. I always had a hard time cleaning the box out . My hitch is going in a new 2008, this is why I was not sure about if I will get a liner. I see some people with sprayed liners but since it was never removable I just could not see my self going that route. A friend mentioned the spacers may not be legal and the hitch should make direct contact with the box. If this is true a plastic liner would have to be cut.

Get a spray in liner and forget about it. It's the first thing I'm going to do. You won't regret it, box liners are a thing of the past IMO.

My liner is cut out around the rails so when i trade it or sell it i'll put in a new liner and take out the fifth wheel only drilled holes in bed none in frame used custom kit for install for draw tite

My bed is Rhino lined...very nice

Line-x first, then have hitch installed.

I just bought a 2007 Classic GMC 3500, I had the B & W Turnover Ball Gooseneck installed then they sprayed Line-X. There are only five holes in the bed and everything is flat when not in use, you can add their fifth wheel hitch to the Turnover ball setup without any other holes, it leaves a nice clean setup and you can use your truck to haul anything, even sheets of plywood.

I put a rubber mat in mine. The box is already beat up from previous owner. Then I just cut a flap door for my gooseneck. I would do the same with a 5th wheel. I would cut some slits, make a door that I could slide over the plate, and then I could lay the mat down and cover up as much as possible. Then if I need to clean under it, I can just pull it all off.

Doesn't protect the sides of the bed, but mine was already beat up.

The problem with plastic liners is stuff gets under them and rust out the beds really bad. I used to have one and learned my lesson on that. Pull the bedliner and mount your hitch. I would not use spacers. If you have the coin get it spray lined if not then keep it open and clean.

I just installed my superglide 5er hitch in my new LMM.(see my garage pics) I cut 4 holes in the bed and I mounted the brackets under the bed. I will get my line x sprayed on Saturday. I used no washers and when I remove the hitch, there are only 4 holes left exposed in the bed.

Spray it then install the hitch, linex woudl be my choice.

The previous owner of mine installed the B&W turn over hitch and had the bed Line-Xed = Lucky me. The sprayed liner is NICE. I hope to be in a 5th wheel soon so all I have to do is pick up the 5th wheel companion. Very slick setup, free and clear bed when I need it.

Get the spray in liner you will not regret it. I had the rhino spray in liner done to mine before I installed the fifth wheel hitch back. In my 2500 it had the drop in liner and when I removed it to put in the hitch it had rubbed some of the paint off of the bed and was quite nasty under the liner. I will never have another drop in liner again. The spray in liners are a little more expensive but they are well worth it.

I have a Sig. Series Reese and had it in my 05 with cut out bed liner. Hated it. Went with Line X this time and I like it a lot better.

I just had mine sprayed with reflex liner over the rail then put stainless bed rail caps over that; then installed the fifth wheel hitch. if your not going to get your bed sprayed dont bother with the drop in junk had one in my 97 and it wore off the paint to bare metal

line-x first, then have hitch installed. x2

Line-X. Then, install hitch.

Steve

I disagree, I installed the hitch and then sprayed Line X. The spray protects the metal from rust and looks much better than the rough hole saw cut that you will have to make. It can also hide any scratches that you make while cutting the holes.

I would always mount the rails before putting the spray on liner in, because the liner will compress, and it is harder to get the rails to stay tight. I have the rubber mat, cut to fit around the rails. I have seen a liner that was heated, cut and ironed out flat under a set of rails, looked pretty good, but not sure if I want plastic between the rail and the frame mounts.