First mod on our new 2017 Rubicon Recon was to install a rear seat recline kit. I purchased a kit from a reputable company in Ohio that came with black Delrin blocks/spacers for the seat. Read below for helpful info if your installing similar kits...

Removing the factory bolts wasn't difficult. I didn't have access to an air ratchet, however a longer breaker bar helped.

Installation was an issue with the supplied 19mm longer bolts. The rear seat frame, spacer/block and threaded hole didn't want to line up. I spent over an hour trying to align. Read a few posts on several forums where others had the same issue and they modified their seat frame (I wasn't about to file or cut into a brand new Jeep seat frame).

While trying to line-up all the parts together I decided to try one of the new longer bolts without the block/spacer in the rear seat. I could not get the longer bolt in the threaded hole. I tried the front holes and they worked. Thought this was odd so I tried all the threaded holes. Yep, all the back holes wouldn't accept the longer bolts from the kit. They only fit the front. I have no idea why other than the factory bolts have a tapered end.

Since most other rear seat recline kits reuse the factory 18mm bolts for the rear spacer, I decided to give them a try. Sure enough they worked and pulled all the parts together and were aligned. I used the longer bolts from the kit on the front without issues. I added a little anti-seize lubricant to all the bolts as well.

With the rear seat kit installed, my kids said it was a noticeable difference. I sat in the back and could tell it was more comfortable.

Lesson learned: When provided new bolts, test fit before installing to ensure they are a match with factory threaded holes.

Here's a pic showing the angle of recline from the outside. Wish I would have taken a "before" pic.

 

Noticed the same when I installed the aluminum version in my 2011 last week. I just reused the rear bolts as well. The grip length of the threads on rear bolts was still sufficient.