Home Forums Gear Hunting Trucks and Four-Wheel Drives 12 valve Cummins

Anybody have one? I sold my 1994 2500 regular cab long bed about 4 years ago and have been kicking myself ever since.

Looking at an early 98 QCSB 2500 4x4 now with the 12 valve. Pretty good condition, basically stick with the exception of a few minor mods and exhaust

I am seriously considering it. They are amazing engines

I'm NOT selling mine! '93 w/ just shy of 180000miles. All stock.

One thing, you can't put a Compression Brake on them unless you change out the valve springs as I understand it. That is why I specifically waited until the 98&1/2's came out with 24 valves

The early 98's are the most desirable 12 valves. Saddlesore is right about the exhaust brake, gotta change the valve springs to make one work. Fix the killer dowel pin and drive it.

https://www.genosgarage.com/product/tst-kdp03/engine-upgrade

KDP is already tabbed in the truck I'm probably buying

This one also has the NV4500 but I'll need to upgrade the 5th gear nut and the original is prone to failure

I've got a 98.5 24 valve with the NV4500. 385,000 miles on it, a lot of it pulling heavy, and I've had no problem out of the 5th gear nut. Even if it does come off it usually doesn't do any damage, you just lose 5th. Unless you just want to tinker you might consider just letting it ride & fix it if it ever gives you trouble.

Now you give me some thing to worry about , 150K on my 98.5 and no trouble with 5th

Dad has a 92 with the 5 speed getrag with around 300k. Still runs like a top

I have a 97 4x4 with 5spd, 387k on it. Motor is pretty much bullet proof, no problems with the 5spd (NV4500). 241D transfer case is garbage as it is chain driven. I've gone through 2 of them and have changed over to an Atlas 2. Front end has been rebuilt with urethane bushings, Thuren trackbar and Dynatrac freespin kit with upgraded axles and a Detroit Trac in the pumpkin. I love my truck and won't be selling it.

Do you like the Dynatrac setup? Get any better mileage?

The Dynatrac setup is great. I got 1-1.5mpg increase in fuel economy which helped offset the 1.5-2mpg loss in fuel economy when the fuel formulation changed 10yrs ago. I also love the manual hubs with this kit, I got Warn hubs and not the Dynatrac. Steering feels a bit freer/looser. I don't have to worry if the front end is engaged because of a leaky vacuum line or if its frozen from getting immersed in freezing water.

Difficult to install? It's a pricey kit but I may be in the market for one. I prefer manual locking hubs

I didn't do the install. A buddy of mine who's a mechanic along with a friend of his who's a heavy machinery mechanic did the install. It's good to have friends that can do stuff like that

Bought it...










A lot of people consider this one to be the "holy grail" for Dodge diesels because they made so few 1998 12 valves and these have the updated interior with the rear doors. I'm thrilled and I can't wait to fly to NM and pick it up

That is a good looking truck!

Interior is incredible for a pickup that old. Nice looking rig

Didn't you buy a sweet Tundra a couple of years ago? How do you find such nice rigs?

Wow! 98's are the holy grail 12 valves with mechanical lifts and to add with a manual transmission makes it even a rarer find!

Nice find!

Yes sir and thanks! This is the stable, all vehicles are tools and are used for specific purposes

This is my Toyota pickup I purchased 5 or 6 years ago from Nitemann here on the fire...



I use this to run around the country I hunt when I'm by myself and in a hurry. It'll go anywhere and with the 22re and 5 speed gearbox it sips gas

This is my 06 Tundra with Old Man Emu suspension and 255/85/16 ST Maxx tires. This is when I have more than one client or I need to haul the family somewhere



This will probably be the truck I sell if I sell one.

The 98 Dodge and the 93 Toyota are the kinds of trucks you keep forever due to the simplicity, reliability and economical nature of them

My Tundra took me 4 months to find, I bought it for the 4 doors and the drivetrain which is the 5 speed automatic and the 2UZ-FE (4.7 liter V8) which is as good an engine as Toyota has produced imo

The little red Toyota was pure luck as I posted a WTB ad here on the fire

Same with the 12 valve I just bought. I wasn't looking to buy but always looking for a truck if that makes sense. Sold my last 12 valve 5 years ago and have been looking ever since

Looks a heck of a lot better shape than than my 98.5

Mine too

Mine hasn't looked that good for a long time.

Pretty cool truck, looks almost new. Probably pretty rare to find a manual in that nice of shape.

Nice truck, just like voiced above, those engines are darn near bulletproof. Lots of them rusted out around here, but engines running strong. We had one on the farm, best pickup we ever had...

First phase is completed and that was to baseline the truck and make sure that anything that needed to be addressed was addressed and the fluids were changed. I replaced the original clutch with a South Bend 13125OFEK clutch and flywheel and it is awesome!!! This clutch is so nice. I also replaced the clutch slave and master cylinder, replaced the rear main seal, replaced the transfer case output seal, put on a 5th gear but retainer, fixed a leaky gasket where the posi lock goes in, replaced my battery cables with a custom heavy duty set, put on Nitto Terra Grappler G2 tires in 285/75/17 on third gen alloy wheels and checked the valves and replaced the valve gaskets. We also tuned it back a little and it doesn't billow black smoke as I go through the gears. The drivability, at least for me, is much improved.

Second phase will be the suspension and I am either going to go with Thuren springs and Fox shocks or the springs that frojoe is having made. I'll see how he likes his and make a decision. I am also wanting a pacbrake but I will wait a bit for more funding before that happens

I apologize for the tire shop parking lot pic. I won't be headed to scout for a few weeks....

Looks nice. Those wheels look good on that gen. If you end up selling the Tundra, let me know - I might be interested.

Will do! I'll probably hunt out of it this year but will definitely let you know

Damn nice

Had a chance to take the truck to a ranch I outfit hunts on in NM this past weekend. I wanted to get it out and see how it would do and see if there was anything that needed immediate attention and the truck did great. I averaged 18.7 MPG for the entire trip and I'm happy with that

Got to get away and see amazing country. I glassed a bunch of elk, deer and sheep and checked a bunch of trail cameras







A better suspension is next on the list but it may be a couple months before I pull the trigger on it

Loaded up the family, rented a Rockwood Roo Hybrid toyhauler and headed to Grand Teton National Park. It's not normally how I roll BUT it's been a fantastic trip so far. The wife and kids are thoroughly enjoying themselves and that makes for a great getwaway.

I've always wondered what one of these 12 valves would get for mileage if you kept it between 35 and 50 mph and today I was able to find out. Daily driving it over the past month I've seen anywhere from high 17's to right at 20 mpg. If I'm on the interstate it'll get right at 20. The other day I filled up at the campground and we made the run to see Old Faithful and a few other sights with the kids and we made a 142.7 mile loop and ended up back at the filling station at the campground. I filled it to the brim as I normally do and it only took 5.737 gallons. I couldn't believe it! We never got above 2k RPM's for any extended period of time and probably averaged 45 mph. It got 25 MPG on the loop. Crazy how efficient these old trucks are if you keep the RPM's down

Huntsonora: My 1996 Dodge 4x4 extended cab five speed has the 12 valve Cummins engine - I have been especially happy with it and the truck as a whole.
It gets great mileage and only comes out of its enclosed garage to take me Hunting or fishing.
I have 142,000 one owner miles on it (average of about 6,700 miles per year) and hope it will be the LAST new truck I ever have to buy!
No "mods" no "exhaust" just a supremely reliable and economic truck!
Hold into the wind
VarmintGuy

Huntsonora: On the highway I get 22 to 23 M.P.G. (with camper shell on it) at 66 to 68 M.P.H.
Maybe I should drive even slower and get even better mileage?
Hold into the wind
VarmintGuy

My 97 has 253K miles and still going strong. 5 speed manual. Definitely not stock. I replaced injectors, turbo, air system, and a bunch of other stuff 10-15 years ago. I've also been running an exhaust brake since 2000 with no problem. Don't know where that myth came from! Pulled lots of horses and at least 6 bumper and fifth wheel trailers and 4 of the biggest and heaviest Lance campers. Best of all, it has the brakes to stop them.

The engine gives over 375 horse power with almost 700 foot/pounds of torque. Used to get 18-20 around town, 22 on highway, but now doing only 18 for everything.

I've have many offers from douche bag 20-30 somethings wanting to "build" it and drive around town with the tow mirrors up all the time. Mirror [bleep]! I'd never let this truck go to one of those dicks!

Added an all aluminum Denver Off Road bumper with 12k lb Warn winch today. Thuren or Carli suspension next...

gonna add a lightbar?

I am. We have a lot of deer and elk as well as black angus cows down in NM and it'll be nice to be able to see them.

That's one sexy ass bumper!

What tuner you running to pump out 160 more hp and 260ft lbs more torque out of the 5.9?

You tune a 12 valve with a screwdriver. That's why I love em. Its impossible to use a "tuner" or a chip on a 12 valve

Not impossible, one could always install a computer controlled fuel injection controller. I can't see why one would do so, but any thing is possible when common sense and budgetary constraints are ignored.

Lol, ok. Or they could buy a 24 valve.

So with a screwdriver one can crank out 160 more hp out the 12 valve 5.9??

Pretty much. It's the cheapest, easiest diesel to make power with. You might upgrade the injectors, mod the fuel plate, advance the timing and add 4K gsk springs but you use a screwdriver to do all that so I guess the answer is yes, with a screwdriver. Point being it's all mechanical so you don't chip it because there's nothing to chip unless you do as 458 Lott said was possible and add computer controlled fuel injection which defeats the purpose of buying a truck with a 12 valve anyway

I'm sure no diesel mechanic, but do some of my own work. Someone mentioned you cannot put a compression brake on a 12 cylinder Cummins. .Mine is a 98 &1/2. First of the 24 valves back then. My user manual on the compression brake that I had put on in 99,says not to install in a 12 valve diesel as they require a 60 pound compression valve spring. Changing out the valve springs to that spec or above will permit the compression brake to work. At the same time it said not to use on an automatic transmission. Since then, with automatic lockup torque converters, that may be done. I understand most compression brakes are electric now. Mine is vaccum operated. ONlyrelayinhwhatmy manual says

The trick on the traditional wheel bearings for the front end is to use 88ish ford f250 front end parts. The stubs match the axle at the ujoint and the spindles out are ford. I think the rotors were dodge....I forgot.

Late to the party, but I'll throw in my name on the "dibs" list for the Tundra. I regret selling my 05 Sequoia with 275k on it....

Ahhh, the Holy Grail of 12Vs, the 1998 QCSB 4x4

All you have to do is change out the 6 exhaust valve springs if you don't want to buy a set of 12.

Yes, tiny flathead screwdriver + hit a couple locknuts + turn a couple screws = almost double the stock HP & torque on a 12v

Keep that injection pump & injectors happy with your favorite lubricity additive added to the silly ULSD fuel, or use 2% biodiesel except in deep winter.

I think the VP44’s benefit more from lubricity additives but I do run TCW3 2 stroke in the 12 valve. I’ll run 1/2 to 1 ounce of 2 stroke per gallon of diesel. It’s noticibly quieter

I also try to run 2% biodiesel when I can find it

Not to mention my humble VE pumps.....

I've got a 93 12V in a 2wd truck with 75,000 miles on it. Use it for towing a 4000 lb supply trailer (I'm a contractor). Also have a 99 24V 4x4 5 spd, 180K, used for pulling equipment, 14K excavator, Bobcat. . Good trucks.