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HOW TO: Extend passenger seat. Increase leg room. No Welding

27K views 26 replies 12 participants last post by  WoodButcher 
#1 ·
This is a build thread of how to add 4 more inches of leg room to the front passenger seat will still allowing it to move back and forth on the original rails, there is no welding needed, only minor metal cutting/grinding on the new brackets not on the original equipment which can be achieved by an angle grinder, and fastening of bolts. This mod can be reversed at anytime and you can go back to OEM.

I did this because my 'full sized' friends complained about the lack of leg room and did not like to ride in the van because of it. Now they have no qualms about riding in the passenger seat, they can fully stretch out their legs. Unfortunately GM/Chevy did not leave much room in the passenger side for peoples feet. So this is a quick cheap fix(10$).

I will go from start to finish.

Starting with the tool & material list.
Tools you will need(or I at least used):(refer to pictures below)
Ratchet Set
Angle Grinder, with a metal cut off wheel and a metal grinding wheel.
Drill and Drill bit(I used 7/16")
Vise(optional)
Eye protection for grinding and cutting.

Parts:
Four - 6" cuts of angle iron. I went with 1½"x1½"x3/16"
Four 3/8" bolts, Four lock washers, Four Nuts. I went with Grade 8 for strength and even did a larger shank then what was on there, so I know they are strong enough.(refer to picture at bottom)

Quick note:
I do intend to pull this all back apart and paint them with a gray primer, so that they match the van.

I wanted this not to be a permanent thing if I decided I didn't like it or something, So I didn't want to have to do any type of welding or anything like that. So this is totally reversible if your not happy with it.

Removal of seat:
Remove any attached equipment you may have to the seat frame, underseat storage.
0422131632.jpg


Loosen and remove the 4 nuts that hold the chair frame to the floor, then lift the chair up and out.
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Remove the four bolts that hold the rails on to the chair frame.
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Now I determinded that 4 inches more of space would be adequate will still keep the main structural integrity of the seat.
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You could probably use a thick grade flat stock, but I chose angle iron because it is stronger and having the lip on there would keep it from really doing any deflection or deformation when you had someone sitting on the chair with it in the all the way back position, especially if they had the back rest lowered or if you were out four-by-ing. I wanted it to be really strong and not able to bend.

After looking at it for a moment or two, I decided how I wanted to mount it.But I wanted to remove a ¼" of an inch from one side of the angle iron so it wouldn't drag against the seat stand.
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After I cut it and ground away the sharp edge to make it nicer. I am doing my preliminary looking at how I would like to attach these.
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0424131812a.jpg


Here is a picture of the bracket ground down, I only ground it down enough to make it look alright, If you wanted you could take a fine grit sandpaper to it and make it really nice and smooth, after painting this will be fine enough for me, I just didn't want someone cutting themselves on a sharp edge.
0424131813a.jpg

0424131813.jpg


Here I attached the rear bracket to the seat frame. I drilled one hole to see if this is where I wanted it, it was, so I marked it for the next hole while fitting it. (also I had to widen the stock holes on the stand to fit my larger bolts, just used my drill for that)
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So I decided to drill the hole's 4 inches apart which would give me a seat setback of 4".
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I attached the front brackets to the seat frame and did a test fit of the stand, and then determined that the stock bolts needed their heads ground down a little bit so I took about half the head away for less clearance.
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0424132018a.jpg


Now I was ready to attach the stand to my new brackets and to the seat frame.
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0424132027a.jpg


The seat picture will be in the next post since I have ran out of my attachment space here.
 
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#2 ·
Now I set it in the van bolted it down and had my friend who was complaining about lack of leg room try it out, he said it was perfect he could stretch his legs out fully now.
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:banana:
And I am done the only thing left to do is to pull it back out and spray paint the new brackets, I think I will spray the stands too because in my van some of the paint is peeling off of them.

Here are the nuts and bolts I used.
0424132048a.jpg


NOTICE: Remember when doing this you are changing the seating position of the seat. If by chance you were to get hurt by not securing the bolts tight enough or by means of the air bag going off to far away, or seatbelt failing you, or any other malfunction. You are doing this at your own risk. I just told you how I did it, and claim no certification or anything against damages.

Thank you for reading my build, and I hope this inspires you to get out there and work on your van. Feel free to leave comments I will leave this topic open for people to add their :2: or what they think of it, when I do finally get it out and paint it I will post pictures of that :D
 
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#4 ·
picked up a couple of rattle cans, will pull the seat off tomorrow and spray the brackets and repaint the base also
 
#5 ·
Didn't get the weather I was looking for till late sunday.

So I pulled the seat off the frame and pulled my special brackets off gave them another quick sand with my angle grinder this time with a piece of sandpaper wheel I believe 400 grit, so it smoothed out the edges a little bit more then the metal grinding wheel did, but like I said previously I am not going for anything to 'spectacular' After that I gave them a spray with some gray rust-oleum, I bought another can that I thought was going to be close that I was going to hit them up with a second coat, but upon doing a test spray it wasn't what I wanted, to shiny. So they will stay this light gray until I can find the right 'slightly darker' gray color. If I can't find it I may try to order the color match from the dealer ship(or if you guys know a good place to get interior body paint colors for these vans that would be nice too)

Heres some pics.
Spray 01.jpg

Spray 03.jpg

Spray 02.jpg

Spray 04.jpg

Spray 05.jpg

Spray 06.jpg

Spray 07.jpg

Spray 08.jpg


Now they've been curing all day inside, so I may decide to put it back together and install it tonight. We'll see.
 
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#7 ·
Thanks CC!

Heres another photo.

Found a color that was closer then the gray primer, it is a little darker then I would have liked to have gone, but it will match my dirty carpet gray... :rofl: .... If it ends up bugging me in the future I may try to match it exact to the OEM. But for now I am sure this will do.

Going to reinstall the seats tonight and take final pic!

0430130657.jpg
 
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#8 ·
here you go, all painted and back in the van.
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Hope this inspires you to do your own modifications.... If I can do it you can do it... believe me :D
 
#10 ·
Thanks Mr. Bowtie,

I think I may do it to the drivers side now too. As it is now it sits far enough back for me, but it moves all the way forward to where my knees are in the dash. So I really don't need it that far forward, and it looked pretty simple to do because that side is electric.

Plus I think I want to spray all my seat bases with that darker gray now, its kind of grown on me now... and the seat bases for my rears look like crap because they have been taken in and out so many times...
 
#11 ·
Has this been stickled yet????

:rofl:
I need to look that one up!
"Stickled" is what the spell checker came up with. :shrug:
:rofl:

Nice write up SB, I just came by to check the numbers because I need to move the queen's throne in my '93. The Gen 1 van is worse than the gen II so I had to do something for her. Come to think of it in my '97 I changed out the seats many moons ago with those from a suboobaroo so I may have move the passenger seat back a bit with that.
 
#12 ·
Update:

The passenger seat has been used by my friend multiple times. I get no more complaints about lack of leg room or cramps :D

This thread should be stickled that would be a good idea.

Glad you enjoyed it :D
 
#14 ·
Finished, with the seat and my rib-eye, the bride is pleased...
I always get fed when I please the queen :lol:

I did it a little different, took about an hour. I used 1/4 x1 steel, 5" long, holes 3 1/2" OC. 3/8" dia. for the seat bolts and drilled and tapped for 5/16" 18, 3/4" to bolt through the slides. I bent the front pieces in the vise so the mount downward to allow for the arch of the seat base.
Easy-peasy, thanks for the ideas and pics SB!
 
#15 ·
Thanks WoodButcher, glad that I was able to inspire you to fix your queens throne.... Now wheres my piece of the Rib-Eye? :dance:

Glad you were able to do it in a nice timely fashion, I could have probably done mine quicker and a lot more simpler, but I am kind of a perfectionist when it comes to some things, so thats why I ground it down like I did and primed it and painted it and all that jazz.

I am sure yours came out nice, would love to see pics of it.
-SB
 
#17 ·
AstroWill said:
I bet is is REALLY easy to remove the doghouse now :)
Have not tried yet, but when I do, I will be sure to post my success :D
 
#19 ·
Looks pretty good, I knew when I was doing mine that I was way over engineering them with the angle iron. But better safe then sorry in an accident. Yours look good and not obtrusive, you probably can't see them from the sides. :thumbup: :thumbup:
 
#21 ·
I'm a little late to the party, but I just stumbled across this topic because my son was complaining about pass side legroom. For anyone thinking about moving the seat location /swapping seats, be aware: This completely changes everything as far as crash safety. These mods would in no way meet Federal NHTSA requirements. Technically, the requirements are FMVSS (Federal Motor Vehicle Safety Standards). Moving the seat location changes the loading into the mounting base no matter how strong the extension pieces are. It also changes the entire seat belt geometry compared to the certified OEM design. There is a huge amount of effort put into seat and seat belt design and testing by manufacturers.

I've also never seen any aftermarket captains chairs, in any conversion or motor-home, that would meet FMVSS. Conversion companies and RV manufacturers get around this by claiming an exemption if they build 500 or fewer vehicles per year( I think this is still true, it's been a while). If you've seen the video of a Winnebago crash you know what I mean....sawdust everywhere!

I did testing for many years at a competitor (4 letter name, ends in "d" :cool: ) including FMVSS cert testing.

Safe bet is replace your Astro seats with other junkyard Astro seats and make sure to use OEM fasteners and bolt torques.

Now I'm not saying don't do it- but if you do, you might want to increase your following distance to the vehicle in front of you..... :)
 
#24 ·
It's not uncommon even for OEM seats to break in accidents. A lot of mods that we end up doing wouldn't pass safety standards, but it's good to be aware of these facts.

The one I'm thinking of is the s-hook mounts I have in my front pillars for hanging my hammocks, I really do need to design a removable setup for them for the new van.

Then again that makes me think of how Provan bolted the rear seatbelts into the plywood floor in the rear of the Tiger(not that anyone should be riding back there anyway), that might not pass today either ;)
 
#25 ·
Regarding Astro/Safari mods and oem safety equipment vs modified oem equipment: Its not as if our Astro/Safari platform in its stock oem configuration is a model of five-star crash greatness (see link below). But...its good to be aware of how an oem stock Astro/Safari will perform when stopped by an immovable or heavier object...and how an end-user mod may or may not contribute to safety and performance. Hey shiatsu happens, but in the meantime we should do our best to be safe whether driving solo on a deserted road or sharing a muli-lane cross-street infested roadway with other motorists. I'm 6ft tall with (ahem) robust proportions...and I wear size-14 boots, so I'll be doing this mod.

 
#26 ·
Thanks so much for this! I'm a bit too tall for the Astro and I've been trying to figure out how to get another inch or two of leg room.
Now I need to find another inch of headroom.
Are the mechanical seats able to be lowered? The electric ones have the actuators in the way making lowering the mounting frame a bit difficult. But I will find a way.
 
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