“I Just Got An Amazing Deal One Of The Greatest American Pickup Trucks Ever” I wrote earlier this week after spending under $5000 on a 129,000 mile, four-wheel drive, manual transmission, rust-free GMT400 pickup — a Chevy K1500. Now I’ve owned the truck for a couple of days, and while I love it, I also think that maybe I didn’t get as good of a deal as I thought.
The first thing that got me is something that I didn’t think would be such a huge deal. During my test drive, maybe I did notice there was a bit of input shaft bearing noise when I was off the clutch, but how expensive could a new NV3500 five-speed transmission possibly be? They’re a dime a dozen.
Unfortunately, I was mistaken. It turns out that early the NV3500 only went into GMT400 trucks in 1993; prior to that, these trucks were equipped with a dastardly Getrag five-speed — the 5LM60, also called the HM290.
Transmission Digest — a publication devoted to the transmission repair industry — has a whole page on the HM290/5LM60, and it’s bleak.
“The HM290 was by any standard an extremely complex unit that most technicians considered time consuming and difficult to work on. The unit requires some essential tools, available through Kent-Moore, without which working on it is all but impossible.”
[…]
The 5LM60 …uses the overly complicated and cumbersome four-rail shift design with its myriad number of parts. In 1993 the 5L60 went through further design changes and was designated the New Venture 3500. At long last the four-rail system was scrapped and replaced with a single-rail
Someone on Car Junky automotive forums claims to have been a trained GM transmission technician, and he/she also has very little good to say about the 5L60:
When I received training at the GM training center in Minneapolis in 1991 on this transmission. The training manual (which I still have) refers to it as a 5LM60 Formerly HM-290. At that time I was told the transmission was currently being built by New Venture gear and New Venture Gear is a joint venture between GM (Muncie transmission) and Chrysler (New Process Gear).
In 1987 it was referred to as MG-290 My guess is the G is for Getrag
In 1988 it was referred to as HM-290 HM= Hydramatic / Muncie
In 1989 it was referred to as 5LM60
In 1991 it was referred to as NVG 5LM60 NVG= New Venture GearThere are two designs for the input shaft, input shaft bearings and main shaft bearings. The first design, which documentation will show as 1988-1990, had a ball bearing and a roller bearing behind it. The second design only has a ball bearing but it was a much larger bearing. The first design bearings were more prone to fail. They were failing when these trucks were under warranty with very low miles on them.
There is no way I would suggest fixing your transmission. The bearings are very expensive. Last one I did an estimate on, it was over 2 hundred just for the GM input bearing. The input shafts are different so you can’t put the better bearing in the earlier trans. Also if you take apart the main shaft, many of the parts cannot be reused, and you need an oven and melt sticks to heat the parts to the correct temp for pressing them together during reassembly.
A large holding fixture (special tool) is used to hold everything in position when assembling the transmission.
It is almost always less expensive to replace these transmissions then it is to rebuild them. Even in parts prices alone. It is hard to find good used ones.
But that’s on me; I should have looked at that odometer when I was test-driving the truck, and I should have done a bit more research into the different transmissions of the various K1500 model-years. Alas, it’s my second recent California car-purchase blunder, and while I still don’t think it will lose me any money when I resell, it is a bummer.
The rest of the truck is in good shape. There are a few loose bolts holding the transmission crossmember to the frame, but I’ll just tighten those. The AC leaks at one of its Schrader valves, but I bought a tool to fix that without having to evacuate the refrigerant:
And the headliner is shot:
And the radio makes loads of static
The biggest issue is the odometer (which I can fix easily) and the transmission. If I can get the transmission replaced for a reasonable sum, I honestly won’t care that much about the odometer. Sure, the truck’s value took a hit, but as far as usability, this GMT400’s motor seems healthy, the frame is solid, the body is straight, and pretty much all systems are a-go except the transmission input bearing and the AC.
It’s still a good truck, but just not quite the deal I thought it was.
on the one hand, i’m sorry that you didn’t buy the perfect truck. on the other hand, i’m glad that even a total car expert doesn’t notice things during the test drive.
cause my last buy was pretty bad and I was too excited to notice the problems.
I wonder if the odometer was disconnected during previous transmission work. Which might also explain the loose cross member bolts as well. The truck is certainly old enough.
Ahh the goofy era of GM transmissions. Just like how the Fiero had Isuzu and Getrag transmissions at the same time for no good reason.
Sucks that you got the bad egg, but if you found a junkyard NV3500 you should be able to rebuild it on your bench in a night and have a solid transmission going forward.
Wow! I haven’t seen Transmission Digest in years. Ever since the local lap dance place GRINDERS closed. They used to have free copies at the bar to peruse. I seem to recall the publication briefly tried to get all millennial and trendy and re-branded as sTD. I should check out one of Torch’s illicit tail light dens. Maybe they have copies there.
For what it’s worth. Even Lego makes parts that will fit that truck, so maybe just spend sometime in a junkyard.
A lamp dance place with a magazine called STD! The jokes just write themselves.
Sounds like a terrible Gentleman’s Club.
I mean, if you’re there, even at the bar, and the most interesting thing to look at is and old magazine…
well, it had to Tracy itself somewhere LOL
First, as a Kern County resident and a lawyer, I would have warned you about trusting ANYTHING from our mountains and deserts. Including and maybe particularly Tehachapi.
I’d honestly be worried this is a grey market truck that can’t be legally registered in California. Particularly given that odometer issue which suggests it had a guage swap to disguise its origin in Mexico or elsewhere. (The original would have metric units – a obvious sign of a foreign vehicle.)
I literally had a case 20 years ago involving one of these, so I’m not kidding.
At minimum, I’d recommend demanding a current smog certificate on any used vehicle that runs, and checking the VIN on the title versus the dash. A good mechanic (or DT) should also be able to tell if the intake manifold and smog equipment was recently removed or replaced – a common way of clean piping a foreign vehicle.
Here’s hoping it’s just a crapcan, and not a scam…
That headliner makes me think you are right. It has clearly forded a deep river at some point.
As if Bakersfield is any better.
Don’t forget your initial impressions of the truck. Even if the mileage is higher, it appears cared for.
The transmission? Put some money away and drive the current unit until it pukes.
These issues are minor, enjoy it for what it is and put it on the fix-as-fail plan. It’s not your daily, so worst-case you’re out a tow call one day.
This is why I warn people that going cheap can get awfully expensive.
Still, you have a solid truck here. With a new or newer transmission you’ll have it set for years of service. The rest of the broken systems can be fixed as you go, or not fixed if you don’t want to. A/C was still an option in most vehicles of your truck’s era. You can fix a broken radio with a cheap Bluetooth speaker and your phone. Even replacing the head unit with something more modern won’t cost you too much.
A GMT400 near me for this money would have giant holes in the body and frame, so you are still ahead.
I wouldn’t worry about the transmission noise until it’s louder than the engine while driving.
Also, you should expect quite a few minor problems. While the GMT400 trucks have a relatively solid platform and powertrain, basically everything around the engine is less then great. The interior quality is just straight up bad. The gauges on those dash always have problems – it’s a miracle yours are working. The radios are notorious for failing and there isn’t an easy way to switch to something else. The automatic climate control systems like to break actuators and then your truck just goes “click click click click click” constantly. The electrics on those trucks are also pretty sketchy in general – the bulkhead on the passenger side of the firewall with the bolted ring-terminated electrical connections feels absolutely archaic – even by late 80s standards.
I think the interior and electrics of the same year Fords was a bit better sorted
(especially when we get to the OBS generation), but they had the weirdo front suspension and slightly problematic electronic transmission.
There is only one (modern) aftermarket head unit that fits pre-1995 GMT400 trucks: the RetroSound “Santa Cruz”. Obviously no screen or CarPlay/Android Auto, but at least there’s Bluetooth and a radio.
Thank you for reminding me that those trucks are not as great as they might seem to someone who doesn’t like modern vehicles (me). Every time I look for one they seem overpriced and I wonder about all the little issues, especially since they are now all qualify for Antique plates. Any tips for the best simple, solid pickup?
I’m sure you’re a little disappointed that it’s not quite as good as it seemed, but it’s still good and, after all, every day you wake up and see the sun is a gift.
I don’t mean that in some treacly hyper-positive “every day is wonderful” way. Every day is most certainly not good. Most days are both too slow and too fast and involve some substantial degree of existential pain. I simply mean that every day you wake up without a knife sticking out of your chest with your lovely and patient wife’s fingerprints on the handle is undeserved bounty. Take the win.
T56 price while providing a sub t56 trans is a choice
This is mountains from molehills liking at a 5k truck.
The trans will likely last thousands of more miles before it becomes a serious issue and if it doesn’t a used 3550 or an NV4500 is an easy swap.
Yeah I was going to say if he really needs a new trans why go for an actual new one and not look for a used one?
Because articles about problems that sound massive and insurmountable get views.
It feels like the manufactured drama of a reality TV show.
Eh, I’ll give you $6 grand and take that junker off your hands 😉
I would suggest to take that offer and run. Then find something better.
Oh man, with a little spit and polish that thing is worth so much more than that here in the rust belt. Luckily he won’t take my offer, because if he did I’d have to dig up $6 grand from somewhere!
Oh shit. Bidding war now.
That’s still a solid deal and looks like a solid truck. You’ll come out ahead. Could’ve done worse, it’s not a Mini Cooper S with a N14 and 100k miles.