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Discussion Starter · #1 ·
Hi All :

I thought I'd pass on my recent successful mini-project to resolve the passenger seat height issue so passengers don't have to feel like they're sitting on the floor. First, apologies for going back and forth between metric and SAE but, I find SAE easier to visualize distances but the hardware specs need to be in metric to purchase the correct parts.

I first looked at the third-party parts suppliers solutions and felt that $200+ (I live in Canada and so must be punished) for their kits was expensive for what amounted to a bag of market-available hardware and so I began a month-long investigation on acquiring similar pieces, which I'll share here.

Firstly, all the hardware is M10 (10mm) and I removed one bolt to use as a sample to enable the hardware matching. The approximately 1" factory bolts are also a combination of a bolt, flat washer and lock washer all in one however, they do not separate. So, these three pieces need to be sourced separately with an obviously longer bolt. I wanted to keep the same depth of thread going into the car frame so I chose a 70mm long bolt (Full bolt spec. - M10X1.25X70mm). This gives the passenger seat a rise of around 1.5". Now, to take up the now longer space between the seat rail and the car frame, I chose metal spacers or washers (Full spacer spec. - M10X30mm). You could really use almost any solid stable material by simply drilling a hole through the middle of it and cut so fits under the seat rail. However, with the spacers, you can stack up more or less spacers to get to the desired height and even change the height in the future. In my case, I used 15 spacers to get to the 1.5" seat rise with another spacer and lock washer on top of the seat rail (64 spacers + 4 lock washers). All the hardware was black oxide metal so it get's lost in the gloom of the footwell and so you really don't see it.

Installation is a little bit tricky but pretty much the same as the third-party kits in that you have to "slot" the rear seat rail bolt holes so the new bolts will fit. KIA very "kindly" elected to tap the seat bolt holes on a slight forward and rear angle so that if you raise the seat rails up, it causes a misalignment with the seat rail and the car frame holes. I needed to enlarge the seat rail mounting hole by one full hole towards the rear of the rail to correct this. I drilled a new hole and then used a Dremel tool to make the sides straight. The third-party kit suppliers don't tell you that in their product description, but read the buyer comments. To start the installation, remove all the seat bolts buy lifting up the plastic doors in the front and removing the entire plastic piece in the rear. Prop up the front of the seat with something like a small piece of 2X4 slightly higher than the new seat height. Lubricate the new bolts and run then in and out the frame holes until they go in nice and smooth. Starting with the front, pre-count (all four have to be exactly the same) the hardware and stack it up beside the frame hole. Put the bolt, with the two upper washers through the seat rail holes and move the stack of spacers over the frame hole and then lift the bolt partially out of the frame rail hole until it clears the top of the stack and then drop the bolt down through the spacer stack until it sits in the well were the threads start. This is very important, you should have previously put some WD-40 or other lubricant in the frame hole and now hand start the bolts into the frame. The reason for this is to prevent any possibility of cross threading the new bolts which if occurred, would cause a major headache to repair. Leave the first bolt as lose as possible and repeat the process for the second front seat bolt, also leaving that one lose as possible.

You can "slot" the seat rail at any point after the seat bolts are removed, but I did mine with the front bolts installed but lose. Test fit the now slotted seat rail and the new bolts by swinging the seat up/down and with the seat at the approximate new height and once again test fit the new bolts to ensure they go in smooth and easily. If your slotting is not back far enough, you will find the bolt angle will not allow the bolt to easily start. If that is the case, simply remove the bolt and Dremel a little more off the rear of the hole. The last hole is a little tricky in that you will not be able to raise the seat high enough to clear the top of the stack and so you have to "load" the spacers three or four at a time, holding the spacers up as they are "holed" until all the spacers are loaded. then let the seat down while making sure no spacers fall out and once again, hand start the new bolt. Once all the bolts are started, simply tighten all the bolts to a fair degree of torque and you're done.

Once all the bolts are tight, the seat should feel like a rock with no sway or movement of any kind. If for any reason you want to revert this modification back to factory, you can simply take out the spacers/bolts and reinstall the factory bolts leaving no visible trace this was every installed. Also, this mod will not interfere with any other movements of the power seat.

Good luck and hope this works out for you !
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