Going from dual rear wheel to single rear wheel, and 24 vs 12 valve pros cons

Jb1rd

Explorer
My search continues and it seems to me that dual lays are more plentiful in the dodge family as are the 24 valves, is it worth the time effort and money to wait for a 12 or are 24 good candidates? My only dodge experience has been 2 5.9 a 06 crew cab and 07 mega cab we had for our contracting business and we bought both of those brand new. I know this might be a bit of Pandora's box but I seem to be pretty good at opening them :sombrero:
 

redthies

Renaissance Redneck
Well, there are things to like about both 12v and 24v Dodges. I'll fess up at the start and say I love my 12v dually. I think the 12v is a simpler, more reliable engine and it will be worth more now, and in the long run. The down side of a 12v is the kdp, which can be fixed for far less than $100. 24v engines have the #53 blocks that are prone to cracking, and the lift pump failure issue. These are both $1000 + repairs. You can make good power with either. 12v by mechanical tuning, and 24v by adding a chip.
 

MT6bt

Rock hound
I thought the #53 block and the lift pump issues also happened on the 12 valve?

That being said, the growing consensus among cummins owners is the 12 valve is the best engine; due to its simplicity, reliability, economy and how "cheap" it is to repair and achieve good power out of.
Like redthies said, it will also be worth more now and in the long run. I bought my truck 1.5 years ago, have driven it 30,000 miles and could still sell it for the same price I bought it for.
 

bikemanx2

Observer
You also have the option of converting an early 24 valve to the mechanical p-pump on the 12 valve thus eliminating the electronic pump. Don't remember the details but I know it's possible.

Sent from my SCH-I545 using Tapatalk
 

Darwin

Explorer
I just went 700 miles on a tank in my new 97 12 valve 5 speed manual. Not bad gas mileage for a big truck.
 

Mundo4x4Casa

West slope, N. Ser. Nev.
I guess I need to chime in on 24v engines. IF you had a #53 block, some of them went south. Mine was not. The lift pump issue with the 24v Gen II is way overblown, usually by 12V., Gen I and Gen III, or Ford owners who have never owned one. It is wise to relocate the lift pump to the frame in front of the fuel tank as it becomes a pusher instead of a sucker, and you loose a lot of the vibration you had with the pump on the engine block. I did this cheap fix. I also added a low fuel pressure idiot light, idiot as i am. A failing lift pump is the #1 culprit in loosing an injector pump. It's starved of fuel which is used to cool the apparatus. There were a couple itterations of the 24v Cummins. In the 2001-2002 era, the regular output 235 HP, 460 pound feet of torque, increased in the H.O. to 245 HP, 505 pound ft. of torque. Also the compression ratio is higher in the H.O. giving the ability to make even more power easily. Both of these have the legendary 'low end' that slowly went away with the Gen III and IV motors.
I have really had very little woes with the 24V engine. It get pretty good mpg, not quite as good as the '89-97, 12V's. When I was running empty I constantly got 18-19 mpg, and with 2600 pounds of camper on got 15 mpg going 55, and 12 mpg going 75 mph. The 12v sweet spot on rpm's is about 1600, right on peak torque, whereas the 24v's sweet mpg spot is 1850-1950 rpm a little closer to peak HP than the 12v.
The 12v can be tuned to produce a lot more power and torque. So can the 24v.
I guess my only reservation about the 12V's is how little power they make (in stock form) and how awful all the transmission lashups were. Yes, all of them.
'89-93 160 H.P. and 400 # ft. TQ
'94-95 160 H.P./400 TQ w/ auto (these were purposely detuned as not to rip up the dainty little Mopar trannie)
175HP/420 TQ w/manual (slightly less detuned for the slightly less dainty manual)
'96-97 180 HP/420 TQ w/auto 420 TQ (we're getting into the Diezel Warz now)
215 HP/440TQ w/manual (this era manual trans was built to take more gut busting torque)
98-00 during this 1st year, the end of the 12V's. 215HP/420TQ w/auto
235 HP/460TQ w/NV4500 manual
'01-02 235HP/460TQ w/NV4500 manual and auto
245HP/505TQ w/NV5600 manual. this is the first Mopar trans that could take the heat, so to speak with that gut-thumping Cummins in front of it, and is reflected in it's non-detuned-ness.
Which is better? Depends on what you want out of it, how much you want to 'fiddle' with it, and how much you are willing to pay for it.
I guess i have just been the luckiest guy around since I've had so little trouble with the 24v.
regards, as always, jefe
 

MT6bt

Rock hound
@Mundo4x4Casa. Thank you for that description. It was very informative.
I agree on the transmission. Mine is still running well with 170k on it but who knows how much longer it'll last. I am seriously considering swapping a NV4500 or even a 5600 if possible when the day finally comes.
 

Mundo4x4Casa

West slope, N. Ser. Nev.
MT6bt,
You've had good luck too, i see. Mine is only @ 146K mi. My neighbor across the lane from us was so impressed with ours, he traded his much newer F-250 4x4 for a used '01 Dodge 2500 like ours except with the auto trans. It looks sharp and runs great, especially considering the mileage on the truck/engine. Three-hundred seventy eight thousand miles. Yes, 378K mi. I'm sure there are 12v's out there with even more miles piled up, but you won't see Ford and Chevy diesel truck owners holding up their hands. I bought the CTD because it had the best chance of outliving me. So far, so good.

From a Dodge representative I got this info about people ordering autos vs. ordering manuals. This was back in 2001. He said the ratio was roughly 100:1. One out of a hundred ordered manuals. I was one of those. Right now, Dodge is the only truck mfgr. of the big 3 that you can order a manual trans. Ford and Chevy have dropped out of the manual business. Why? The newest automatics are SO superior to the ones of even a decade ago that they are just waiting for us stick-shift, old-timers to die off, since the new crop of kids can't drive a manual anyway.
I can add this observation re:diesel engines in general. The farther you get away from stock; the more you 'hot-rod' the engine, the more woes you will have with the drive train. The reason i jumped in '01 to a Dodge is because of the drivetrain; front to back;top to bottom. The engine has enough power, but not too much for the rest of the drivetrain. The NV5600, six-speed manual is encased in cast iron. No aluminum/flexy, bearing eating case need apply. The downside is it weighs 360 pounds/dry. A total boat anchor.
NV5600 Ratios: from low to high: 5.63/3.38/2.04/1.39/1.00/0.73/5.63R
NV4500 Ratios: from low to high: 5.61/3.04/1.67/1.00/0.73/5.61R aluminum case. Notice the big hole between 2nd and 3rd. Some woes with the 5th end gear nut coming loose. Somewhere along the line they reverse threaded the shaft and that fixed it. It's still not built to go behind a hot-rodded engine.
The transfer case: it was the first year they put an NV241HD t-case in there. What's the big deal? The NV241, non-HD has the narrow chain for normal off-road use, but the HD model has a very wide chain to mitigate the effects of shock loading while snow plowing. The rear output bearing is the same, so they are rated the same because of that weak point. That's why I ordered the snow-plow prep package. It was like $25 more for the HD t-case. This was the first year they put a true 35 spline, FF, 1.53" axle diam. Dana 80 in there. Previously, only the V10 had the 35 spline shafts.The Dana 80 has a 13,500 pound max load rating. Quite a bit higher than the Dana 70's that came with the 12v. Previously, only the V10 had the 35 spline shafts. My 2500 came with a Camper Package, which included upper secondaries (or overloads) just like the 3500 duallie. In fact is was the first time Dodge did a 2500 with a 3500 suspension making it a defacto SRW one ton. Virtually everything above was the first year they did these upgrades, and that's the reason i jumped for a 2001.5 CTD. What's the .5 you ask? One major change around mid-year was addition of disc brakes, to the rear. The best manual trans that Dodge puts behind the CTD is the German/Mercedes Benz G-56, 6 speed transmission with a stump-puller low gear. The ratios: 6.29/3.48/2.10/1.38/1.00/0.79/5.74R
That's enough,
regards, as always, jefe
 

redthies

Renaissance Redneck
I thought the #53 block and the lift pump issues also happened on the 12 valve?

There were a very limited number of 12v with 53 blocks, and for some reason they didn't seem to crack like the 24v 53s do.
I have heard of a few 12v lift pumps failing, but all that happens is the truck runs poorly. When a 24v lift pump goes, (most if not all stock ones do, that's why FASS and Airdog etc are in business) it WILL take out the injection pump. This is due to the unfortunate design of the VP44 ip that uses the flow of fuel to cool the electronics piggybacked on the pump. It is not a deal breaker to have a 24v with a stock lift pump, but the savvy 24v owner will spend the few hundred bucks to put a quality aftermarket lift pump on to avoid the inevitable failure of the stocker, and the resulting death of a costly injection pump.
 

redthies

Renaissance Redneck
I guess I need to chime in on 24v engines. IF you had a #53 block, some of them went south. Mine was not. The lift pump issue with the 24v Gen II is way overblown, usually by 12V., Gen I and Gen III, or Ford owners who have never owned one.

Jefe, do you have a 53 block? I know a lot of them have been fine. It's just a bit of a roll of the dice. I will however have to disagree on the lift pump issue being "overblown" by non-24v owners.

I'm not one of those guys who thinks what they have is better than everything else (just most other trucks:D). Probably the nicest DRIVING Cummins I ever drove was a 2000 with 24v and NV5600. I've since learned about lift pump issues, 53 blocks and the rarity/cost of parts to rebuild a NV5600. If it hadn't been so filthy and beat on, I probably would have bought it, and may have had to deal with some or all of these issues.

All of the generations of Cummins have their idiocincracies, you just need to buy with as much knowledge as you can get.
Cumminsforum is a good place to learn about the various incarnations.
 

evilfij

Explorer
As a perpetual cummins shopper, the first gen trucks all seemed to rust out on the east coast no matter how well cared for. The trans all seem to be crap with 12v first gen. Second gen seem to rust less, but still rust and all seem to be auto in my shopping.

The unicorns are out there, but not around me. A low miles extended cab 92/93 W250 with a manual ....

Missed a 93 rust free (came from Florida) W250 extended cab auto with a blown trans about six months back. Still sold for 5k ....
 

redthies

Renaissance Redneck
Evilfj, you should start shopping in Florida or other points south. You will save way more than airfare and fuel to get home buying down south. Lack of rust, and lower prices are everywhere, and hell, this IS ExPo, surely you WANT to drive it home, no?
 

Darwin

Explorer
I just picked up 1997 from the original owner in mint condition 5 speed with BD exhaust brake for 10k, not cheap but not overly priced in my opinion. I'm happy, it's my second 12 valve.
 

UHAULER

Explorer
MT6bt,
You've had good luck too, i see. Mine is only @ 146K mi. My neighbor across the lane from us was so impressed with ours, he traded his much newer F-250 4x4 for a used '01 Dodge 2500 like ours except with the auto trans. It looks sharp and runs great, especially considering the mileage on the truck/engine. Three-hundred seventy eight thousand miles. Yes, 378K mi. I'm sure there are 12v's out there with even more miles piled up, but you won't see Ford and Chevy diesel truck owners holding up their hands.

This is silly. There are plenty of 7.3 fords with High miles. I personally know of a 99 7.3 ZF6 trans with over 560 thousand miles on the original turbo,injectors and HPOP.Trans never been touched.

The perfect truck for me would be a 12V Cummins in a Ford with a ZF transmission But I don't have the time or the place to do it so I bought the cleanest, low milage 7.3 I could find.

Most people who talk about how long an engine will go(myself included) will never put that many miles on a truck before getting bored and switching vehicles.
 
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MT6bt

Rock hound
I just picked up 1997 from the original owner in mint condition 5 speed with BD exhaust brake for 10k, not cheap but not overly priced in my opinion. I'm happy, it's my second 12 valve.

And acquaintance of mine picked up a mint condition 97 reg cab manual with 70k on it. Topper, custom bumpers, and a winch. The owner of it passed away and the lady barely got the "FOR SALE" sign on the window before he picked it up.

OH, yeah...he got it for $6500. BASTARD! That truck could easily sell for 14k
 

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