Extend Your Seat!

Here's some good repair guides for your Tercel :) Look here for help first!
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Abletobecain
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My tercel:: 1983 4WD DLX, 1986 4WD SR5, 1985 4WD SR5, 1983 4WD SR5
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Extend Your Seat!

Post by Abletobecain »

I'm not sure if this is the right place to post this as it's a modification, not a repair, so please move it if it should be elsewhere.

So I'm 6'3" and I don't fit in my T4 that well. I didn't think it would be a problem but I drive about 50 miles a day and I developed a nasty muscle knot from my gas/brake leg always being cocked at an angle.

I was looking for seats that would directly swap in or someway to extend the stock seat. At Petros' suggestion, I got some angle iron and "rigged something up." Thought I'd make a post if anyone else want's to extend their drivers seat.

First, pull your seat (obviously), remove the trim panels from both sides and unbolt the seat bottom (4 bolts).

You'll find the slider mechanism (that's attached to the brackets that bolt the seat to the floor) is riveted to the seat frame in five places...3 large rivets and two small rivets.

All of the following pictures are from the inside rail but it's the same process for the outside rail as well.

These are the rivets that need to be drilled out.
Image

I started with a small bit, then a larger one, and finally a 5/16" bit popped the rivet out completely. Start with one end on the large three rivets and drill all the way through. Then move the slider to get the other outside rivet. For the middle rivet, drill carefully and stop as soon as you're through. A piece of the rivet will pop off and get trapped inside the slider which you'll work out by moving the slider back and forth while it's upside down after you drill out the two small rivets. The two small rivets (maybe spot welds?) don't go all the way through so you can go straight at them with the 5/16" bit and stop as soon as they pop.

When you're done, it'll look like this...Slider separated from the frame.
Image

I used 1 1/4" x 1/4" angle iron cut to 20" which will extend your seat back 4" when it's all done.

Image

Mate the front edge of the angle iron with the front edge of the slider (which will make the angle iron extend 4" to the back of the slider) and mark the two holes. Make sure the angle portion is on the inside of the seat so that your trim will bolt back on. Then drill the holes out of the angle iron.

Next you'll set the seat frame on the angle iron so that the frame goes to the very back edge of the angle iron (forgot to take a picture here but it's pretty straight forward). Mark the three holes on the angle iron and drill them out. At this point you'll temporarily bolt the angle iron to the seat frame using the two outside holes. Then flip the seat over and drill through the seat frame for the back slider mount hole.

Image

Now you should have four holes through the seat frame and it's time for assembly.

First bolt the angle iron to the seat frame using three 5/16" x 3/4" bolts, a washer, a lock washer, and a lock nut on each.

Image

It ends up looking like this.

Image

Next you bolt the slider to the angle iron using two 5/16" x 1" bolts. Put the bolt through the slider and then stack 4 washers (to compensate for the bolt heads on the previous step) before running the bolts through the angle iron and securing them with a washer, a lock washer, and a lock nut on each. (Sorry for the blurry pic)

Image

Now you need to notch the angle iron so that the rear seat pan mount will fit back to the original bolt hole. It should look something like this:

Image

I didn't want to cut all the way through to the angle of the angle iron (and compromise the strength) so I notched the rear seat pan mount a bit so that the angle iron would slide into it.

Image
Image

Repeat the whole process for the other rail, then you bolt the seat pan back in, reinstall the trim panels, and install your seat back into the car and it ends up way back there!

The passenger seat is stock in this pic:

Image

My leg angle before the extension:

Image

My leg angle after the extension:

Image

I took it on a decent drive and it feels fantastic...what a relief!

I've also realized that you can put just about any seat you want into your car using this process. I saw some nice black leather Pathfinder seats at the junk yard that I'll be snagging soon.

Hope this helps someone!
1977 BMW R100S 1WD ("Brunhilda"/Summer Fun)
1983 DLX Tercel Wagon 4WD ("Charlie"/Daily Driver)
1987 SR5 Tercel Wagon 4WD ("Sprocket"/Off-road-Camping)
1985 SR5 Tercel Wagon 4WD ("Lucky"/Project)
1983 SR5 Tercel Wagon 4WD ("Cadaver"/Parts Car)
1985 Ford F250 6.9IDI ("Franklin"/Hauler)
1987 SR5 Tercel Wagon 4WD ("Ravensburger"/in a million pieces)
2006 BMW 530XI Wagon ("Inga"/Roadtripper)
1969 Mercury Montego MX Convertible ("Big Ed"/My Dad's Old Car)
1983 SR5 Tercel Wagon 4WD ("Al"/for sale soon)
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ARCHINSTL
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My tercel:: Goldie is a 1986 SR5 attualmente con Weber/also owned the first T4WD in STL in late '82
Location: Kirkwood, a 'burb of St. Louis

Re: Extend Your Seat!

Post by ARCHINSTL »

Well done and certainly well described!
Tom M.
T4WD augury?
"Oh, do not ask, 'What is it?' Let us go and make our visit."
T.S. Eliot - "The Love Song of J. Alfred Prufrock"
"Now and then we had a hope that, if we lived and were good, God would permit us to be pirates."
Mark Twain
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simon84
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Location: Banff, Alberta, Canada

Re: Extend Your Seat!

Post by simon84 »

Great work! Thanks for the comprehensive repair guide.
I've wanted to modify my seats but I've wanted to lower the seat. I'm 6'1 and I always tilt the seat way back so that my eyeballs are not at such a high vantage point and so that I have a bit more space. But the leg extension thing is interesting to consider. I hadn't noticed it except I find that I try to balance the leg extension with arm extension to reach the steering wheel. I have made a steering wheel mount for an after-market steering wheel that does bring the steering wheel out about an inch, which I like. And it's not so far that you can't reach the signal toggles etc. I should get pics of that on here somewhere.
Your how-to guide is encouraging me to have another look at this.
I'd appreciate any tips on lowering the seat. I think even an inch might help. I doubt that lowering more than an inch would be easy or even possible. I have had the seats apart to re-cover them and it's a lot of work but turned out great. I guess I can also consider pulling them apart again and possibly shaving some foam to get my butt lower. That might be easier.

I have to ask, is that a baseball bat tucked in beside the gear shifter?
Please explain?
Cheers
Driver: 87 Tercel SR5, white, 4ac, weber carb (aka the Tercedes)
Road Tripper:95 Mitsubishi Delica L400 2.8L Turbo Diesel
Motorbike: 94 Kawasaki Ninja ZX6
Project Car:Red 68 Plymouth Sport Fury III
Previous Tercel:Orange 84 Tercel 4wd (aka the pumpkin)
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Abletobecain
Top Notch Member
Posts: 415
Joined: Sun Dec 09, 2018 9:18 am
My tercel:: 1983 4WD DLX, 1986 4WD SR5, 1985 4WD SR5, 1983 4WD SR5
Location: Kitsap County
Contact:

Re: Extend Your Seat!

Post by Abletobecain »

Thanks Tom and Simon.

Simon, I'd love to see some pics of your steering wheel extension. I can still reach mine pretty well but I mostly grab it on the bottom now and I'm only using about 3" or my possible 4".

My seat mod definitely doesn't help with seat height...actually raises it about a 1/2" from the bolt heads and the angle iron. I think lowering it would be a PITA. The first thought that comes to mind are that the holes for the seat pan bolts are just holes in the seat frame...the nut part are on the seat pan so maybe you could drill new holes lower on the seat frame?

Yea...that's a bat shoved in there. I've always kept one in every car I have. Kinda my version of a Trunk Monkey...anyone remember those commercials?! https://youtu.be/XW8iAVwt_Yc
1977 BMW R100S 1WD ("Brunhilda"/Summer Fun)
1983 DLX Tercel Wagon 4WD ("Charlie"/Daily Driver)
1987 SR5 Tercel Wagon 4WD ("Sprocket"/Off-road-Camping)
1985 SR5 Tercel Wagon 4WD ("Lucky"/Project)
1983 SR5 Tercel Wagon 4WD ("Cadaver"/Parts Car)
1985 Ford F250 6.9IDI ("Franklin"/Hauler)
1987 SR5 Tercel Wagon 4WD ("Ravensburger"/in a million pieces)
2006 BMW 530XI Wagon ("Inga"/Roadtripper)
1969 Mercury Montego MX Convertible ("Big Ed"/My Dad's Old Car)
1983 SR5 Tercel Wagon 4WD ("Al"/for sale soon)
User avatar
ARCHINSTL
Goldie Forever
Posts: 6369
Joined: Sat Apr 30, 2005 1:52 pm
My tercel:: Goldie is a 1986 SR5 attualmente con Weber/also owned the first T4WD in STL in late '82
Location: Kirkwood, a 'burb of St. Louis

Re: Extend Your Seat!

Post by ARCHINSTL »

@ Abletobecain:
O - M- G - ! On the Trunk Monkey link!
I just sent it to a bunch of my motorhead buds!
Thanks!

My version of a Trunk Monkey - and - it fits under the DS seat!
https://www.autozone.com/test-scan-and- ... /48199_0_0
Granted, it is not as long as a bat and prob not as 'whomping' as a bat, but it is perhaps easier to deploy - and - it has pointy ends!
Tom M.
T4WD augury?
"Oh, do not ask, 'What is it?' Let us go and make our visit."
T.S. Eliot - "The Love Song of J. Alfred Prufrock"
"Now and then we had a hope that, if we lived and were good, God would permit us to be pirates."
Mark Twain
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