I need some expertise. I have a over-the-rail spray-in bed liner on my '94 F250 4X4 (with 20K original miles:~) I would like to install a tonneau cover but have been told by the Extang folks that theirs won't work due to the over-the-rail spray-in liner. Has someone on this forum installed a cover with a over-the-rail spray-in liner? If so, could you please advise of the manufacture/type?

Thanks...

 

Have a Downey SST cover (http://www.downeyproducts.com) installed on my wife's '02 F150. The way the rails are clamped to the bed, I don't see how an over-the-rail spray-in bedliner would interfere. In fact, on their FAQs page, they even talk about using their cover with an over-the-rail DROP-in liner!

 

I just installed a Extang RT Tonno cover yesterday on my 04 Superduty. The only problem I had was with linning up the side rails. When I would tighten down on the clamps they were not square. Had to add shims in the back.
I also cant see how the over the rail spray in liner would interfere in you case. The instructions for Extang mention that if you have a over the rail (bed liner) you may have to trim. Anyhoo the Extang is a nice cover.

 

The only real reason the tonno cover might not work would be if the spray liner was too thick the clamps might not fit. You could get longer screws to get the clamps to work if you go with Extang. Make sure you use never seaze on the screws because they usually are a pain to get back out after a few years.

 

I have the Downey LTD never had a problem and dry as a bone.