Seat Height Adjustment

[nyprius]

<div class='quotetop'>QUOTE(darelldd @ Aug 2 2006, 11:57 PM) [snapback]296777[/snapback]</div>

Maybe the adjustment was put in to boost the short guys??? Or.. maybe they couldn't reach the EV button without this feature.
[/b]

I was thinking of that Darell, but the seat is already high enough for anyone over 4'6". The 5'3" person above told us she thinks the seat is perfect for her. And it is.

I always assumed the Japan Prius didn't have seat height adjustment, in the same way it has rear drum brakes and narrow tires, like the US Prius. I figured they were speading the pain around fairly. It blew me away when I learned (in the great referrenced post above) that the Japan Prius has seat height ajustment and the US Prius doesn't. I don't understand how they could make that oversight. Are they intentionally trying to annoy or insult taller drivers in the US? Again, I don't get it.

[dogfriend]

Originally Posted by nyprius

At 6'1", I feel the Prius driver's seat is too high. I like to ride with the seat back up all the way since it's more comfortable for my back on long trips. When the seat back is leaned all the way forward, I often must crouch down to look up at traffic lights. Also, my vision out the rear view mirror is restricted by the sloping roof. If there's a slight upward slope on the road behind me, I can't see very far behind me. I must use the side mirror instead (ie: if the seat was lower, I would have much better visibility out of the front and rear windshields). Also, the top of the speedometer numbers are cut off by the dash due to my high angle over the dash. And my head is too close to the roof of the car, which makes me feel more cramped than necessary. [snip]

Lowering the seats seems to be more difficult. Four triangular pieces of metal rise up from the seat rails to support the seat. The seat is secured by one bolt at the top of each triangular piece. It looks like you could drill holes in the triangles one inch below the existing holes and re-attach the seat.

Has anyone tried this or figured out a different way to lower the driver's seat?

I had the same issues as you. On my commute every morning I use a freeway on ramp which is a "cloverleaf" type. When decending the right hand curved ramp, I have to crouch down to prevent the rear view mirror from blocking my view of the car directly in front of mine. Last month I decided that I had to do something about it.

There is another post by MrBigh where he cut the rear seat mounts off and lowered the rear of the seat by approx 1/2 inch by welding the mounts to the seat rails. I don't have access to a welder (and I suck at it anyway) so I found a slightly different method to lower the seat.

BTW, I am not recommending anyone do this, and take no responsibility if anyone decides to do a similar mod. This or any other modification of the seat, seat belt or seat mounting could have negative consequences in the event of an accident.

I did the following steps to lower the rear of the seat by approximately .890 inch. :

1. Disassemble the bottom of the seat including the plastic covers on each side, the seat cover and pad and the white plastic pieces on both the inside and outside of the seat frame. The steps are covered in more detail in the Service Manual.

2. Unbolted the track assembly from the seat frame. There is one bolt on each side at the front, two bolts at the rear support where it attaches to the inner rail.

3. Grind off the rivet at the top of the rear support on each side. I used a Dremel tool to do this. There is also a tube which is welded to the support and runs from one side to the other. Leave it in place.

4. Cut the support about 3/4 inch away from the welded tube, so that the support can be removed while leaving the tube in place. I used a Dremel tool with a fiberglass reinforced cutting wheel.

5. Bolt the front of the seat back to the track assembly. With the rear supports removed the seat can pivot around the front bolts. Bolt the rear supports back onto the rails loosely. With the brackets on the outside of the seat frame, you can lower the seat frame down. When I positioned the seat where I wanted, I used a scribe to transfer the height of the hole in the seat frame (where the rivet used to be) to the inside surface of the rear support

6. Drill a hole for an 8mm bolt at the location you scribed. After I drilled the new hole, I measured that the new hole was .890 lower than the original hole for the rivet. Using the new hole, transfer the location to the other support (they are opposite hand parts) so that the height will be the same on both sides. After drilling the holes, I cut off the portion of the support where the rivet originally was located so that it would fit against the seat frame.

7. Bolt the supports to the outside of the seat frame (they were originally on the inside). I used two 5/16 washers between the support and frame so that the support would bolt on flush.

8. Because the supports were originally inside the seat frame, you need longer bolts and spacers to bolt the supports to the rails. You need to use approx. .670 inch thick spacers (two 10mm hex nuts and a 5/16 washer) at each location. Check to make sure the rails are parallel (approx 17 inches at the centerline)

9. Reassemble the seat pad and plastic pieces. I had to do some minor trimming because the supports are wider now at the rear, but all the pieces go back as they were originally.

I drove today and was able to see the cars in front of me in the cloverleaf, I can now see traffic lights without crouching and my hair is no longer touching the headliner.

[zenMachine]

Wow, that's a lot of work for .89 inch. Have you tried flipping your rearview mirror downside up as well?

[dogfriend]

Originally Posted by zenMachine

Wow, that's a lot of work for .89 inch. Have you tried flipping your rearview mirror downside up as well?

I'm aware of flipping the mirror, but this was only one of the problems that I had with the seat being too high. It doesn't sound like much of a change, but in my case it makes a huge difference in visibility. In my case, with the original seat position, my eye point (looking out forward and level) is above the SRS logo on the A-pillar; with the seat in the new position, it is slightly below the SRS logo.

It would be possible to drop more than .89, but would require fabricating new supports, which I was originally planning to do, but realized I could use the original ones.

I actually am considering fabricating new front and rear brackets, and making it adjustable. But I am happy with the result I have now, so my motivation level has dropped

If you look at the photo I posted above with the seat track removed from the seat frame, you can see another seat in the background. This is a Corolla seat I bought from Ebay. I was planning on using parts from this seat to modify the Prius seat but ran into 2 problems:

1. Although it was listed as a 2003 - 2005 Corolla seat, after buying it and studying the Corolla seat service manuals, I discovered that it is a 2003 - 2004 seat, not a 2005 seat. It is quite a bit different than the Prius seat and not suitable for parts.

2. Also, after inspecting the seat when I got it home, I realized that the whole seat track assembly is bent. It appears that the driver was probably hit from the side because the seat track is pushed toward the inboard side referenced from the seat frame. So, it isn't suitable for my car or any other car. Buyer beware.

However, I don't consider it a total loss, because I was able to see how the adjustable seat mechanism works, and I can measure the links and locations of the pivot points to figure out the geometry of how the seat moves. I have some ideas on how to make the Prius seat adjustable, but it will require fabricating some parts.

[ZC1]

Priuschat database posting problems (double post)

Can't wait till Priuschat server changes.

[ZC1]

I'd certainly pay for either a height or length adjustment on my Prius seat rails, God only knows I need the room and I'm merely 6'0".

I noticed the Prius driver seat is higher than the passenger seat and I believe its this way because Toyota attempted to give the driver more downward viewing of the hood (front-end).
I don't feel the seat height helps me in any way, since I still cannot see below the tip top of the windshield washer (on a 2008).

I remember over 25 years ago I had seat distance problems on an Mazda RX-4. Since seat modifications were not readily available, I improvised by swapping the passenger and driver seat rails which worked like a charm.

Unfortunately, for the brief time I stuck my head under the Prius seats last night, the seat rails seem to be similar in length, although the floor attachment points are different.

I'm gonna be a bit disgruntled if the 2009 model year comes with adjustable seats.

In many ways, the Prius is ahead of it's time, in other ways it's behind.

(lack of seat adjustment, lack of heated leather seats, drum brakes, No moonroof option, lack of auto lock doors, lack of auto ON headlights (at least on my pkg#6)... I can find more..)

Still, I highly like this car and find myself trying to personalize it.

ZC1

[wolfganghowell]

Hi All

I have finally made the correct adjustments to lower the driver's seat using Dogfriend's method. I mentioned this in another thread but would like to repeat it here since this were I got the idea from.

Below are my comments about the entire process and results.

BTW: I am not recommending this to anyone and you must do this at your own risk.

* Read Dogfriend's instructions carefully and print out the pictures. They helped.

* The entire process including several trips to Lowes was about 6 hours on a Sunday. (you need access to another car since you can't drive the Prius)

* I used a regular drill with a 3" metal cutting disks to cut the rear support frame off since I didn't have a Dremel tool. Buy a pack of 5 since I used 4 of them during the process.

* I used black tie straps to replace the round hook rings for the seat cover attachements.

Results: I am 6'5", 240 lbs and I can now see clearly and have about 1/2" head room at the top. Before, I had to slotch down with my knees pressed against the dash. Now there is about 1 1/2 " clearance. I drove to/from work for a week now and it is very comfortable. Today my wife of 5' 8" drove and she said she doesn't have a problem with the new seat adjustment and I sat in the passenger seat and WOW, what a difference between both seats. I think I may lower the passenger seat too.

Wolf

[dogfriend]

Originally Posted by wolfganghowell

WOW, what a difference between both seats. I think I may lower the passenger seat too.

Wolf

Yep, on my car I can see the difference in height between the two seats when looking from outside the car, but I don't think anyone would notice unless I told them. I'm pretty happy with it now because my hair doesn't touch the roof like it did before.

[brick]

After 5 or 6 hours of work, I'm happy to say the mod has been completed without a hitch. Grinding those two rivets didn't work so well (overheated and shattered the little grinding stone) but drilling worked very well with a 5/16" black oxide bit. I also want to say that those reinforced Dremel cutting discs are incredible. I managed to get both supports cut with just one! (I have a long history of shattering cutting wheels. ) Some of the trim obviously went on a little funny but I expected that, and could really care less as long as it functions. The only minor hiccup was overheating my cheap-ish black & decker rotary tool, which seems to be on its way out given that some of the magic smoke got out.

It sits well, and I can already tell that visibility is much improved. I'll report back once I've driven around a bit. Mostly I'm just thrilled that I didn't screw something up! Dogfriend, those instructions are top-notch.

[RobinCandace]

I too would like a seat height adjustment but for the opposite reason! I'm a 5'5" woman and I'd like to move the seat HIGHER just a tad so I can see the hood. In my Lexus IS300 I had the seat quite high so I could see a little better over the front of the car.

But that is just a preference thing. I suppose there is no reason I NEED to see the hood. I find my 2008 Prius quite comfortable to drive on my hour-long commute to work.

My husband is 6'1" and he would like a little more leg room and head room when he drives my car. I remind him that I didn't buy the car for HIM.