The GMT400 pickup was launched in 1987 for the 1988 model year and continued in production in various forms until 2002. I’ve never owned one but their appeal to me has grown a lot recently, compared to other trucks of this era. To the point that when I saw that this 1992 GMC version, a long-time resident of my neighborhood, had sprouted a For Sale sign, I had to pause. 4.3 V6 TBI, 5 speed manual, long bed 2WD. A far better utility truck than my own Tacoma. But I’ve talked myself out of it … for now.
Other than this brochure shot, all of the photos in this post are mine, taken over the past couple of years.
Earlier versions of GM’s trucks often had family names, like Advance Design and Task Force, and have been featured here at CC quite a bit. Deservedly so, as they were often design and engineering winners, though some features like torsion bar IFS and coil spring rear suspension may have been ahead of their time. The new trucks didn’t get a family name but became known by the model code GMT400. They replaced the previous generation, colloquially referred to as “Square Bodies”, starting mid-1987 (as pickups; it was a few years before chassis cab and crew cab and SUV versions transitioned).
At the time, I was driving a 1986 Ford Ranger, my second pickup, so I paid attention to trucks and my reactions to the new GM truck were mixed. I liked the styling, and finally GM was offering an extended cab, years after Ford, Dodge, even Nissan and Toyota offered this. But there was also a perception that it wasn’t a REAL truck, reinforced by the fact that crew cab and heavier duty versions, as well as the Suburban stayed with the Square Body design. And the thermally actuated front axle locking mechanism quickly gained a reputation for slow actuation in cold weather, a situation where you might actually need four wheel drive immediately. Maybe rural legend, but I heard of 4wd Chevies stuck in snowbanks because the actuator couldn’t warm up enough to engage the front drive. Eventually GM replaced the thermal actuator with an all-electric (solenoid) actuator.
As I mentioned above, I don’t have any real first-hand experience with these trucks, other than briefly driving and disliking a Chevy Tahoe based on the GMT400, so this won’t be a deep dive into their history. But my interest grew when I saw this truck on the ferry traveling from Bellingham, Washington to Ketchikan, Alaska in the summer of 2023. To be fair it is a 2500, nominally a 3/4 ton, but still quite the load! That’s a boat trailer on top, loaded with building materials. The open tailgate had a new-in-box cast iron bathtub resting on it. And in case you’re wondering why the trailer is on top and not hitched up, I can only guess that it’s because the ferry fare increases a lot for vehicles over 20 feet long.
But not all GMT400’s are sitting by the curb in showroom condition, or loaded to the max with supplies to build a cabin in Alaska. I spotted this one a few years ago in Moab, Utah. And not all trucks in Moab are 4 wheel drive, nor are all bikes there mountain bikes. This one (Chevy? GMC? I can’t tell) sports optional stepside bed (shortbed only) and some handsome styled wheels, though I’m not sure about the whitewalls.
I initially thought I’d post this photo, which I took last summer in Taos, New Mexico, as a CC Clue. But I wasn’t sure if it would be too easy, given the common nature of these trucks, or too hard given the lack of features. I ended up taking a lot of pictures of this Chevy; it just seemed so deserving of getting documented.
Hard earned patina, though the interior plastic and upholstery look quite good. This is a working truck, probably over 30 years old. The logbook on the seat shows that it was last used just a few weeks before I took the pictures (sorry for the reflection) with over 210,000 miles. Still in government service (University of New Mexico).
Just a few hours before writing this post on the Monday after Thanksgiving, I walked past another GMT400. Probably a trade worker’s truck, but also their daily driver. Stripped of all badging, and with an aftermarket grille, I’m again unsure of whether it’s a GMC or a Chevy. And like the white shortbed Stepside in Moab, it’s not quite my style. But it’s still a good looking truck. The GMT400 is a true Curbside Classic.
Joseph Dennis wrote about the GMT400 here a few years ago, featuring a Chevy C1500 he spotted in Flint. Joseph describes that he also felt these trucks were too “pretty” to be taken seriously. We were both proven wrong.
I’ve had my share of time with them,and I don’t like them. I will say the interior in these is light years ahead of the previous version. And I’ve never heard the older called Boxbody, just Squarebody
I think of them as box body but you’re right, Square Body is the more common term and I corrected that. Thanks! If Wikipedia is to be believed, the Square Bodies were officially called Rounded Line by GM but that seems odd; they are hardly rounded, especially compared to their predecessor, which apparently was the Action Line.
I see what you did there…
“…hardly rounded,…”
I owned four of these, an ’89, ’92, ’95 and ’98. My ’89 had the peeling paint issue similar to the one in your Taos, New Mexico photo. I think this was caused by GM using the new water-based paints due to VOC emission regulations and they did not have the formula quite right. My ’89 also had the “Rally” wheels with the thin beauty rings and chromed plastic snap-on lug nut covers. After being popped on and off a few times, they never fit tightly anymore and rattled when rolling. For the 1990 model year on the caps were retained by plastic nuts that screwed on to external threads on the lug nuts as is shown on the Taos truck.
The 4 headlight system used on the up level ’88 and ’89 models was individual sealed beams and I have often wondered if these were the same headlights used on the 1993 to 1997 Camaro. For the 1990 model year on composite headlights were used.
I thought the radio in my 1992 was unusual in that in consisted of 3 components: a control head, tuner and graphic equalizer with a cassette player. I think the vacuum-fluorescent display on the radio and HVAC servo controls was really cool.
The new dashboard and instrument panel in 1995 with driver side airbag was a big change over the ’94 truck and 1996 saw the introduction of Central Sequential Multiport Vortec fuel injection for a big horsepower increase.
The Moab, Utah truck obviously has the similar looking Buick “Road” wheels.
I quite liked the styling of these when they came out; very clean and as compact as a full size truck could be, the exact opposite of current trucks. The initial IP was very cheap looking, but that was improved a few years later.
This generation’s successor, the GMT800, is often considered to be very reliable and a good choice for a used truck.
A writer referred to needing “gorilla” arms to reach the radio controls in the first of these models, and the interior picture reminds me of my neighbor’s truck and that long reach.
These were the trucks around when I was a kid, and while they look ok enough I never really gave them much thought. Hagerty has said recently that these are one of the hottest vehicles in terms of quote requests among people 35 and under, which makes sense if this is what you grew up in.
I had considered one of these as a vintage-ish project/play truck for home projects, but while they’re pretty high on functionality, I still don’t view them as cool enough to treat as anything other than a work vehicle
I have owned several GMT400’s. They were something of a revolution in the full size pickup field when they debuted in mid-’87, featuring a largely welded frame with a boxed front section, flush-mounted glass, and torsion-bar IFS on 4X4 models. Ride and handling were superior to Ford or Dodge and the GM’s cab was very roomy with great visibility. For the most part the trucks proved to be quite reliable and the styling aged well. Clean examples are becoming expensive, particularly special editions like the 454SS and Sierra GT. Here’s an interesting video covering some of the GMT-400’s development:
Here in the Land that Rust Forgot™ I still see tons and tons of these, from hard-working contractor trucks that probably have over 300k on the clock to lovingly restored and modified trucks.
They’re essentially the last of the old school trucks, in that they were pretty much the end of the line for the original Chevy small block & big block engines, before the LS engines began. If you’re an old guy who grew up modifying Chevelles, etc, you know exactly how to work on one of these.
Paul is right in that the GMT800 were probably better trucks, but if you like old-school, these are great!
My appreciation for these trucks grew a few years ago when my brother-in-law acquired a 1993 (I think) GMC 2500 from an older relative who’d used it only sparingly. It’s a great truck, and with the 454, it could probably tow a house. I’ve driven that truck a few times, and I’d consider one if I needed an older truck, though build quality and interior trim, etc. is not the best.
Gotta hand it to the University of New Mexico for getting all they can out of tax-payer dollars. That old Chevy looks like a glacier melting in the sun.
I bought an ’88 K1500 regular-cab, long-bed 5.7L TH700 8.5″ axle in the fall of 1997. Essentially ten years old, 170K miles.
Two engines, two transmissions, one transfer case, one rear axle and one-and-a-half exhaust systems later, it’s got something like 320K on it now. Still running strong. Odometer gave up a while ago. Should be good for another ten-plus years.
Picked up a ’97 K2500 extended-cab short-bed 7.4L 4L80E 10.5″ rear axle perhaps five winters ago. I use it to plow snow. I fixed the faulty logic of the original owner–who buys a plow truck and DOESN’T get a locking/Positraction rear axle? Again, needed (and still needs) some TLC. Starts and runs and pushes drifts.
Correct door count, now youre talking pickup or Ute, And with bed sides low enough to be able to use it as is instead of throwing the wellside in the scrap pile and putting an alloy dropsider body on, Makes me wonder why this simple design went away
The two biggest complaints I see about GMT400 vehicles are 1) Steering looseness, and 2) Brakes.
Steering looseness of course stems from worn steering/suspension components, these trucks are not spring chickens. But there’s a design flaw that makes things much worse–the “rag joint” connecting the steering shaft to the steering gearbox. This “rag joint”–a textile fiber-reinforced rubber coupling–is just too small and overloaded. It soon loses all stiffness, and then the steering is accomplished by the safety-stops built into the coupler. The result is perpetually sawing the steering wheel back and forth to keep a straight course. FIXING this is really easy on ’94–older GMT400s. GM sold a steering shaft (26015779 plus bolt 11610555) that had a U-joint instead of the rag joint (now discontinued.) The aftermarket has stepped-up to provide similar steering shafts. The ’95-newer GMT400s have air-bags, and a somewhat different steering column that the prior shaft won’t work on. Again, the aftermarket has solutions.
Brakes are another matter. 5- and 6-lug-wheel trucks use Low-Drag front calipers, and the attendant Quick Take-Up master cylinder, if the calipers get sticky, the pedal can be quite low. The 1500 (5-lug 2WD, and 6-lug 4WD) usually have the fragile 8.5″ rear axle along with REALLY HORRIBLE 254mm (10″) Leading/Trailing shoe rear drum brakes, and that’s where most of the trouble lies. The 11.150 Duo-Servo rear brakes are an ENORMOUS upgrade for pedal feel, and actual braking power. This brake upgrade is usually accomplished by installing a Treasure Yard “light-duty 2500″ 9.5” six-lug rear axle along with the better brakes. A K2500 six-lug axle for a K1500 truck; a C2500 six-lug axle for a C1500 5-lug truck (so you need the rear wheels, too.) The axle widths are different between C and K trucks. Be sure to match the gear ratio to the original axle especially on 4WD. New U-bolts and nuts, and a conversion U-joint are all that’s needed to fit the upgraded axle and brakes (plus whatever repairs and fluid-change is needed on the Treasure Yard axle.)
The Rear Wheel Anti-Lock on ’88–89–maybe ’90 trucks has an iron body, and a bleeder screw. After that, RWAL or ABS will HAVE to have a scan tool to properly bleed the brakes. Almost nobody bleeds the brakes with a scan tool to chatter the ABS valves, so air trapped in the ABS is common. The combination of three things–faulty low-drag calipers, engineering screwup on the leading-trailing shoe brakes, and air in the system accounts for a HUGE proportion of brake issues on the GMT400 line.
Brakes and steering were exactly the two things I remember about the only GMT400 I’ve driven, which was my brother-in-law’s Tahoe. At the time we had a Land Cruiser FZJ80, which was not exactly a sports car. But the Tahoe’s brakes and handling took me back to the golden age of Detroit, and not in a good way. The 350 V8 almost made up for it, but not enough.
We had a Tahoe of this generation and have generally good memories of it. I liked the styling, the seat comfort, and the power. I didn’t like various small but niggling repairs such as leaking oil cooler lines and especially the little doohickey in the steering column that when it went bad made the wheel “catch and release” as if you hit a patch of ice mid-corner. It helped move us to Colorado without incident, the key to enjoying driving it was being as relaxed as possible and perhaps slouching behind the wheel more than a bit…
When we bought it (well used) I preferred the styling to the successor GMT-800 generation, by the time we sold it I preferred the newer styling.
I do recall when they (the pickups) were released a decade before our Tahoe was, they seemed a huge jump forward from the squarebody. There’s a good book called “Road Fever” by Tim Cahill in which he takes a very early and perhaps slightly preproduction one (’88?) on a GM-sponsored trip from Tierra Del Fuego all the way up to Prudhoe Bay in something like 3 weeks which is a very short span of time for that distance and topography (15,000 miles or so). A very good read, highly recommended, it’s on my shelf of car books…
Ive owned two, great trucks with no serious problems. The one pictured is my current rig, 2000 K2500 C6P (HD payload option) 5.7/4L80E 3.73 gears, State of California fleet auction bargain. Torsion bar front end rides better than lighter, unreliable ’94 F-150 it replaced.
First GMT400 was a ’93 C1500 Work Truck 4.3/4L60E 3.42 posi, purchased new. Close to 100k mostly trouble free miles. Found out, even changing to all-terrain tires, that posi was worthless in mountain ice and snow. Traded for a ’94 F-150 4×4 5.0/E4OD 3.55 gears of similar mileage that was gutless, could hardly stop and generally trouble. That is when I started looking and found the present ride. Burns quite a bit of expensive California gas but no other complaints.
This is what I’m talking about, such a handsome truck!
Nice looking rig there.
Just FYI, both of the trucks you weren’t sure about are GMC’s. Even though they have aftermarket grills, they are the same shape as the GMC grill.
Thanks.
Absolutely my favorite pick-up. We had a variety of these at work, and while I have driven Fords, GMT800s and older Dodges, I preferred these by far. They were very durable in their time at work, where they served for years but not a lot of miles. When our crew had our ’76 Dodge replaced by a new 2500 in 1989, people in other departments, who never borrowed our Dodge, suddenly came out of the woodwork to borrow our new 2500. Later, after a re-organization, I landed on a crew with a new ’95 2500 with the 7500GVWR, a husky truck but still a pleasure to use. I used these trucks during the balance of my career, and have fond memories of them.
I have really soured on GM over the years, but I will always have a soft spot for the GMT400
I worked for a company in the ’90s that had a small fleet of these with several 1/2 & 3/4 tons and a single 1 ton all with gas engines as well as a couple Tahoes. They were overloaded almost daily and we also pulled 25′ gooseneck flatbeds. They would regularly get 300 to 400k highway miles without any major problems.
The first picture and the last one illustrate how I like to see older trucks. All stock and original in good condition, or slightly modified; lowered with nice wheels, a custom grille and good paint. Either way it’s obvious that the owner takes pride in his machine. I hate to see them beat up, neglected, and sun burnt. Don’t get me wrong I don’t expect them to be perfect, they are tools after all, but I also. take care of my tools.
I still see some of these in daily service in my area. These seemed far less prone to body rust than the following generation (GMT 800). A guy I work with switched between 2 different ones for his daily driver until he sold one recently.
I just noticed that the one on the ferry isnt even the 8600lb version that I have, six lug rims mean 7500 and still carries all that load. Due to odd emissions classes, 7500lb version was not sold in California.
I have two of the GMT 400 trucks, a ’99 C1500 Chevy Suburban and a ’97 C3500 Chevy Silverado Crew Cab. Burb has been in the family for 11 years and replaced a very similar Burb we had for 7 years before it was totalled in a wreck. Dad and brother walked away from that wreck, more than can be said for the idiots in the fwd Monte Carlo that caused it by running a red light. A few parts of that first Burb are now on the current one.
This Burb was bought to be a weekend swap meet truck, since we had newer cars for daily driving. But when they both gave out, the Burb picked up and kept going. It has a few mechanical things I need to fix, which have it currently parked. Bought the Crew Cab a few years ago, from the grandson of the original owner, this truck has just under 143K on it, even with the 20K we have driven it. I have had to spend some money on both of them, but they’re still way cheaper than payments. And more suited for my family’s needs/wants than most newer vehicles, and I can still work on them when they need it.
The truck on the ferry, heavily laden, is a LD 2500 as evidenced by its 6 lug wheels. 7200# gvwr, and it’s probably pretty close…but it’s not sagging too much in the back(and probably the cast iron bathtub is responsible for most of that! Since it is behind the axle a bit…). The Buick wheels on the white Sportside are the 5 on 5″ lug pattern from the full size cars, available in 6″ and 7″ width; the wider ones were on the Estate Wagon. We had one of those when my brother was small, and I still have a couple of those wheels.
I see this era of trucks all around the greater Houston, Texas area, every week, and on trips across the state too. I’m a member and regular contributor to http://www.gmt400.com, the largest and best forum group for these trucks; we have thousands of members, primarily in the US and Canada, but many from all over the world.
I had a 1990 Chevy, 2WD, shortbed. It was my work and personal vehicle. It provided about 55k miles of trouble free operation at which point I had to replace the rear U-joint. The U-joint was fixed in place with a genius GM innovation that required plenty of heat to melt out.
That was a foretelling of drive train issues to come that started at the 350 TBI engine and ended at the rear end. Before it became a huge problem, I traded it in for a 1994 Dodge-a vastly superior truck to the Chevy.
My biggest mistake with the Chevy was buying it instead of the leftover 1989 Dodge/Cummins/stick that I test drove. I was annoyed the dealer wasn’t willing to move much on the price. Regrets…
One of GM’s best ’80’s designs. Unfortunately, they appeared to be bad rusters
This is the only vehicle from the late 80s that I -still- see being driven here in the Calumet Region.
I have driven many as working “yard” trucks over the years. They always seemed to be the most reliable and hard-working trucks, jump starting the other makes in sub-zero temps, pushing the others out when they got stuck in snow or mud, and idling for hours on end around the clock. One looked like the silver one in the above picture complete with tool box. It was a manager’s truck that did yard duty as well as his personal transportation.. This was in the mid 90s, when it had over 200,000 miles on it. He was long retired around 2018 when I last saw that truck around town or in his driveway. Plus they were handsome trucks as well. For me these trucks are legendary.
I had a 1997 K2500 for about 10 years, dragged my camper, motos and track cars all over the midwest just fine, but I had to replace the original motor with a Goodwrench crate 350 at ~110k — coming back from camping at the lake one weekend it started knocking and I tried to just get home instead of stopping. Never did sort why the bottom end gave out, but it only held 4 quarts of oil in the sump and I think that wasn’t enough. Pretty truck, rode nice and I loved the color. I had the Cheyenne trim, a half-step up from Work Truck: no carpet but it did have cruise.
In 1998 I upgraded from a 1987 Silverado to a 1993 Silverado. Indigo blue/silver two tone reg. cab 8′ box. Like a pickup should be. I probably never really appreciated that pickup until it was long gone.( Think I drove it 8 or 9 years). Now new ones cost as much as my first house! Should have kept some of that old iron.