How to repair a broken seat.


Registered Member
Sorry if it is in the wrong place.

Difficulty: easy if you know how to weld or know someone that does.
Estimated Time: 45min with vacuuming out crap from under the seat.
Part Numbers: None
Cost: FREE!:biggrin:

Tools Needed:

socket wrench
18mm socket
flat headed screw driver

The drivers seat in my Trailblazer broke from me plopping down on it when I get in. At first only one of the front adjustment arms was broken, so I lowered the front of the seat all the way down. That was fine till the other side broke. So I could now flop the front of the seat bottom up and down. It was getting annoying, every time I got in or out it would shift around, so something had to be done about it. I looked and looked and found nothing online on how to fix it. So I am writing this so others know how easy it is to fix.

Step One:

Remove the seat:
Move the seat all the way forward, there are two plastic cover that need to come off. I used a flat head screwdriver to pop them off. Be careful as they are only plastic and will break if to much force is applied. Take your 18mm socket and remove the two nuts. Now move the seat all the way back. Remove the one plastic cover. Remove the nut and the one bolt next to the center counsel. Unplug the power from under the seat. Lift the seat out.

Step Two:

Inspect the damage. Mine was bent on one side, so I had to bend it back straight. Line up everything, making sure it is all straight and were you want it. Get out your welder and put down a tack weld. MAKE SURE TO ONLY WELD THE TUBE AND THE ARM. If both sides are broken like mine was, make sure that the other side is where you want if and tack into place. Double check it is where you want it and then lay a bead down, making sure to get good penetration on the arms and the tubes. Let it all cool down, in the mean time I vacuumed out the 9 years of crap that was under the seat.

Step Three:

Put the seat back in. Put the one nut and one bolt in the front, replace the cover. Plug in the power. Move the seat all the way forward. Put the two nuts and covers on. Make sure everything works the way it should and moves up and down.

THAT IT! :thumbsup::wootwoot:

Here are some pictures of the broken arms and the before and afters.

Broken Arms



All lined up ready to weld



All welded up. Might not be pretty but they are hell of a lot stronger then what was there.




I typically do not resurrect old threads but I had to thank you for the write up and photos. At lunch today I went and sat in the truck. I'm not an overly big guy and don't "plop" on the seats but mine broke exactly how yours did. In looking at the break my first thought was welding it but not being sure of the construction I wasn't sure it was possible. Now I know! Thanks!


Registered Member
Thread Starter
DocBrown said:
I typically do not resurrect old threads but I had to thank you for the write up and photos. At lunch today I went and sat in the truck. I'm not an overly big guy and don't "plop" on the seats but mine broke exactly how yours did. In looking at the break my first thought was welding it but not being sure of the construction I wasn't sure it was possible. Now I know! Thanks!

Your very welcome!

That's why I love this site!

It was a very bad design on GM's part to only weld the back of those.


Registered Member
I know this is an old thread, but mine are broken too so I'm going to do this.

I'm new to welding so excuse me if these are dumb questions... Has anyone done this? I assume this was MIG? Do you know what voltage you were set at? Any issue with Burn Through? Did you remove the seat covers before attempting this?



Lifetime VIP Supporter
(1) Visit THIS Link to get the Basics of MIG Welder Settings. Remember this… MIG Welding with NON-SHIELD GAS using Flux-Core Welding Wire demands an Electro-Negative Polarity arrangement. This means that the Wire coming out of the Gun GROUNDS to the Work Piece during this process... NOT the Other Way Around. This means you may have to reverse the present “Out Of The Box” Wire polarity attachments inside of your MIG Welder.

(2) I’ll suggest using Hobart Part# H222106-R19 Alloy E71T-11 Gas-Less Flux-Cored Wire @ 0.030” on a 2 Lb Spool as being adequate for this kind of work. Since you are NEW to Welding… Spending TOO Much Money at the outset is just as much of a Big, Bad Sin as NOT spending enough on what is really necessary. The YT Videos on this MIG Welding Topic will make plenty of suggestions on what is necessary. Just look up "" Videos.

(3) It goes without saying the “Preparation of the Work Field and Piece is 99% of the Trouble…” . This means performing the hassle of removing the Seat Cushion from the Seat Frame AFTER the ‘Chair’iot has been unbolted and removed from the vehicle. Set your work OUTSIDE at least Waist High on a small table and prepare the surfaces well in advance using a Wire Wheel over the involved areas.

(4) Beware of welding on either Galvanized or Zinc Coated Metals or Stainless Steel as they produce toxic and carcinogenic gas including Hexa-Valent Chromium. Inhaling these Vapors can KILL You. Also… Use proper Eye and Hand and Skin Surface Protection and set your Auto-Sense Auto-Darkening response within your proper Welder’s Mask NO LOWER THAN LEVEL 9.

(5) Use a LOT of Common Sense well in advance of spending around $200-$300 for a “One-Off Repair” just to prove that you ‘can do it yourself’. Welding anything is really not that difficult, but it requires the Right Tools, The Right Skills and if done thoughtlessly or carelessly ...can get You and other people hurt.

(6) No Offense to your intrepid Chops and Desire to DIY this thing… but realistically, it might be cheaper and wind up with a better outcome if you locate either a Muffler Shop or a Welder’s Supply House and get the local contact of someone who can perform this task for you at much less cost than you might think. This approach could spare you all of the other aggravation and the necessity of having to Learn How to Do this Right… and have to Pay Out all that Moolah ...up front.

(7) If you are Bound and Determined to Soldier On… Visit YouTube and view as many Videos and Programs as necessary for you to get the Gist of the Basics of MIG Welding and then realize that you'd damned well better practice FIRST on some Thin-Wall Square Stock Steel Tubing and/or some similar dimension Practice Steel Coupons to get the “Yips” out of your system before even removing the Damaged Seat from the Truck.

(8) Mind where you do this work, else setting your garage ablaze when incandescently hot metal drippings and dross ignites anything flammable makes everything go sideways and ruins your day. I’m not kidding. You won’t be able to see what has happened around your location in time to react while you’re wearing a Helmet and listening to that MIG Gun making “Bacon Spatter” and sizzling away as you focus in on things.

(9) Plan ahead and have a New ABC Fire Extinguisher close at hand for any and all circumstances. The more these safety suggestions sting your finer sensibilities right NOW… the better it will be if it means not burning your house down later on because you did NOT have any “Failures of Imagination”.

(10) NEVER Weld inside or around your Vehicle around flammable materials ( when the Smell of Gasoline is Present ...and items like Foam Seat Planks are adjacent the Work). Likewise, NEVER ground your MIG or Arc Welder to ANY Motor Vehicle without removing the Negative Ground Cable from the Battery FIRST unless you want to end up having to Buy a Brand New PCM and/or a BCM.

'Nuff Said.
Last edited:


Registered Member
@MRSSM said: (7) If you are Bound and Determined to Soldier On . . .
Practice on similar materials, configuration & position till you are comfortable & satisfied before you attempt to work on the actual joint.
Edit: Make sure the pieces are properly aligned & clamped.


Registered Member
Thank you for the info... It definitely would have been cheaper to take it somewhere... I am taking a Welding class and what I paid for tuition, I could of had this fixed multiple times over... But I've always wanted to learn how to weld, so I'm taking the class. I'm taking the seat into school and fixing it there. The have good MIG guns that use gas...

But... The main reason I am working on this is that when my wife adjusts the seat front to back, it grinds. I looked and saw the broken up-down adjuster so I'm going to fix that. But... I would guess now that will not resolve the issue she is having. When I pulled the seat... I found 1 lone ball bearing on the carpet... I looked at the motors, slides and did not see where it came from. If I had to guess, it came from the slides the move the seat front to back... Anyway, I plan to fix the broken bracket and it that doesn't fix the grinding, I'll just tell my wife not to drive my car... :rolleyes:

Do you know what the rails that the seat slides front to back are called if I have to replace them? (It might be cheaper just to find a seat at the junkyard.)


Lifetime VIP Supporter
Practicing on a Junk Yard Seat Mild Steel Frame also means that you can salvage the parts needed again and again using a 4" Cut Off Wheel... Just keep chopping pieces out of it for practice.

Kind of like what Eric "O" from SMA (South Main Auto) demonstrated last year after he purchased a Miller "Miller-Matic 211" 120VAC MIG Welder + a Cylinder of C25 Mixed Argon & CO2 Gas.

Eric "O" shows that he has very decent Basic Welding Skills by using a few chopped up segments of Square Tubing tuned up with a Wheel Sander and then displays running some very nice beads with his New Rig.

He features describing his own New Machine Set-Up Preferences as well as using the Miller "Auto Selection" features. These options will appeal to Experienced Auto Shop Mechanics as well as with Novice Hobby Welders. This is a VERY Nice Basic MIG Welding Demo "Show-N-Tell":


Forum Statistics

Latest member

Staff online

Top Bottom