The difficulty enhancement engineers at GM strike again

I need to remove the passenger front seat in my Silverado to get some working room on the HVAC system.

Shouldn’t be hard, right? It wouldn’t be until I saw the nuts holding them down. E-Torx! I had never heard of these, but GM decded that the seats should be held down with a nut for which the sockets/wrenches are unobtainable locally.

I went to Harbor Freight and found a set, $26. Took them home, only the E-16 fit the back nuts. The front nuts are larger than the E-18 in the kit. No one locally sells any larger than the E-18.

There is a kit on Amazon that goes up to E-20 but I’m not sure that is even big enough. GM really hates their customers. But I have to admit that the E-Torx look like they would not easily round out out like hex nuts do.

The girl at Autozone suggested that I go to Lowes and get one of those DIA universal sockets. Those are the ones where the pins recess around the head to grip any shape or size (within limits) nut or bolt.

Never heard of an E-torx plus socket?


Home depot has their Husky brand E-Torx that goes up to E-24 for $27

So are the “plus” E torx a different animal than the standard E torx"? Up until a few weeks ago I’d never heard of these now it looks like I’d better get a set or two?


Since I own a Volkwagon Audi Group product, I need triple square sockets as well as E Torx for my GM truck.

I wouldn’t recommend that. My kids got me one of those for Christmas years ago. But just by looking at it I wouldn’t trust it with any amount of torque. Mine has never touched a bolt. Seat bolts require a substantial amount of torque and I doubt one of these tool will work.

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Some may remember my recent post about my Sonoma electrical glitches. I had to remove the steering column cover behind the steering wheel.

For some inexplicable reason GM chose to use 2 t25 torx screws for the bottom cover and a single e25 for the upper cover. I have not checked but I think they even used a slightly different thread pitch between upper and lower screws. Makes zero sense to me.

And GM is not alone. First time I went into a VW manual transmission (Golf) I found the main shaft bearing held in by a thrust plate. The plate was held to the case by five 5.5 MM Triple Square fasteners; all with very countersunk heads. Again, no earthly reason for this and for not using the common 6 MM TS ones in use forever.
Seriously? New tooling/hardware to shave a half MM?
VW special tool was on back order and it took me over a week to come up with an alternative. Thanks to the Cornwell tool vendor as MAC and Snap-On were futile. Buy a tool, use it once, and never need it again…

Cautionary not on buying Torx sockets - I bought a set on Amazon without paying much attention and they turned out to be 12 point rather than the normal 6 point torx. Those were pointless and would not remove the rear axle bolts on my BMW. Just buggered up a bolt. I had to make an unexpected run to Harbor Freight for 6 point Torx sockets.

I surmise that security of the seat is paramount (crash safety issue), speed and reliability of installing a close second. Ease of removal, not so high a priority.

Out of 1,000 trucks, how many need to have a seat removed in their lifespan?

I remove mine every now and then. Best way to get a good deep cleaning of the carpeting.

What always irritated me about the Big Three was their propensity to use those oddball sizes; as in 7 MM, 15 MM, 18 MM, and so on.

The Japanese got it right IMO. Checking the chassis bolts is a part of the PDI and major maintenance services. Time consuming? Not really.
A pair of 12 x 14 MM and a 17 x 19 double boxed end wrenches will get the job done in a few minutes.

I learned how to work on cars with my 72 Chevy Vega. You could tear apart 90% of the car with just a 9/16 and 1/2 wrench.


You are working with passive restraints, GM may be trying to discourage vehicle owners from disassembling these things.

There might be a tool dealer in your area with the socket, I have three dealers that visit once a week.

The occupant classification system should be calibrated after installing the seat (manufacture’s instructions).

I expect Nevada above is correct, GM trying to discourage owners from messing with safety devices like seat fasteners. Apple Computer did (maybe still does) this sort of thing. The first Macintosh (circa early 1980’s) computer required a special screwdriver to open the case. Sort of like a torx bit on the end 12 inch shaft. Not something the ordinary diy’er would have on hand in other words. In Apple’s case I imagine they were thinking they’d get fewer calls from confused customers trying to put their computer back together if the customer couldn’t open the case in the first place.

I think the seats on my Corolla have that sort of fastener , now I think about it.

Discovered some puzzling GM engineering on my Sonoma recently. The center console lid was rattling. The cover needed to be adjusted forward about 3/32 of an inch for the latch to catch. No big deal I thought.

The cover hinge has 2 Phillips screws; one on each side with a slot for adjustment. They put a 3rd screw in the middle but instead of a slot used a hole. Then in front of that they added 2 holes to the hinge and used nubs from the console in those holes along with the 3rd screw to prevent adjustments. This means if the cover is to be adjusted…

  1. Elongate the 3rd screw hole into a slot and grind the nubs off the 2 forward holes.
  2. Grind the nubs off and throw the 3rd screw away.
  3. Elongate the screw hole and both nub holes.

GM probably spent a quarter million dollars for that Catch 22 design.

Sorry guys, lightning strike Wed morn took out my internet and phone, just got it back. After spending $26 at Harbor Freight for an E-Torx socket set and finding that the front nut was too large for the set I bought, I came up with an idea. Find the best fit 6 point hex socket, then cut two 8d nails to about a 1/2" length. Hold or tape the nails to two opposing slots and fit the hex over it. The would work (I think) to get the front nuts off.

I was just getting ready to try it when I had another idea for what I was working on (the HVAC blend door) and it worked so I didn’t need to move the seat. BTW, I was not going to disconnect any of the wiring to the seat, just unbolt it so I could move it back about 6" to give myself some working room.

So now onward to finish the HVAC issues, I hope.

I’ve having a difficult time envisioning this method. If something like that would work, it seems like vice grips or channel lock pliers would also.

The front nuts are in a hole, only a socket will work.