Yeah, any 3rd Gen with the factory LSD can have the dreaded "C-Clip" issue which can implode the rear differential. Luckily, these clips can simply be pulled with no ill-effect on the operation of the diff or LSD, or you can simply put a better, after-market LSD in.

The 5.9 is a tank of an engine, it's only real issues are it likes to blow the plenum gasket, which causes a pretty major oil leak and loss of power. Parts to fix it for good are cheap, but labor is a bit intensive. Also it's mated with the 42re transmission which is basically the transmission that got earlier Ram trucks the reputation of having the best V8 engines on the planet mated with the worst transmissions. Plan on a tranny rebuild at some point as miles get over the 100k mark.

The only thing I'm gonna warn you about the 5.9 is it likes to drink it's gas and despite it's displacement, it's not much stronger than the 4.7. I had a '98 RCSB 4x4 with the 5.9 and with 4" of lift and 35" tires I couldn't get into double digit MPGs unless I was driving strictly highway AND kept it to 70 mph and then I might manage 11 mpgs.
But the thing has basically been around since the late 60's with only a couple minor changes over the years and with decent maintenance, 200 - 250,000 miles out of that engine isn't a stretch. I personally know a guy with almost 300,000 miles on his 5.9, but he's on his third tranny rebuild.

With the Hemi getting 100 more HP than the venerable old 5.9 at the same time getting about 25% better fuel economy coupled with the fact the Hemi comes with the 545rfe transmission (which has proven to be the most reliable transmission Dodge has ever had in a truck), I'd still look for an '04 or '05 Hemi if you can find one within your budget.

Keep in mind, you start looking at trucks up around 10 years old and they are gonna require maintenance. Simple things like ball joints & tie rods right on up to transmission and possible head gasket, timing chains, etc. which is normal BUT costly and it doesn't sound like you're the shadetree mechanic type. If you can budget maybe $2000 more for a six or seven year old truck with decent mileage on it, you may save that much money in the first year alone on maintenance cost and have a newer vehicle with a better engine/transmission combo at the same time.

Again, I'm not trying to talk you out of an '02 5.9, I'm just trying to prepare you for what you may get yourself into...

 

Thanks again Hammer!

 

Do the 4.7's use the same tranny?

 

The 4.7s initially used the 45rfe, but went to the 545rfe in '03. It's the exact same transmission physically, but the 545rfe has an additional gear programmed in, essentially a 2nd over-drive.

The 4.7 is pretty reliable, it has an issue with oil sludging, but this can be avoided by using a good quality synthetic and changing it at the recommended intervals. It's only real flaw is that the coolant channels sit VERY close to the cylinder walls. So neglecting coolant changes and allowing the coolant to become acidic will eat thru these walls, basically destroying the heads. Again, normal maintenance and this should never be an issue.
Because of this though, the 4.7 does NOT rebound well if it's allowed to over-heat, often this will blow the head gasket and/or crack the heads.

If you find a 4.7, I'd have a mechanic check the oil, look for signs of sludge and have a compression test done, this test will rule out a head/gasket problem. If it passes and YOU take care of it, you should have no issues.

I'm not trying to deadpan any of these engines, if you look at Ford or GM (or Toyota) for that matter, they all have a couple of major flaws. The Ford Tritons blow the plugs out and require costly re-tooling of the heads for example.

Again, aside from initial cost, since the 4.7 gets essentially the same fuel economy as the Hemi, yet the Hemi has about 100 more HP and after the '03 weak springs were upgraded, it has no real common flaws. Some may site the "Hemi Tick" but it's never been shown to cause a problem, it's just a nuisance sound...

 

Hammer: a 42re behind a 5.9? I've never seen that...only 46re's. My old dakota with a 3.9 had a 42re. Also, doing head gaskets on a 5.9? Never heard they were a problem.

As for a hemi vs a 5.9...hemi hands down. Dad has a 95 1500 with a 5.9...farm has a 99 2500 with 5.9 and I have an 06 with a hemi and there's a big jump in power and modest gains in economy with the hemi.

 

My bad, I was just chatting with someone who has a 4.0 I6 and I had 42re on the brain, I meant to say 46re. That's what I get for being on two different forums at the same time trying to make two posts.

As for the head gasket issues, I was talking about the 4.7 - did I screw that up too, or did you just misread? 4.7 is head gasket/heads, 5.9 is Plenum gasket as far as issues go...

 

Maybe I did misread...all is good, you're giving this guy good info.

 

My vote's for the hemi. Get a shop to replace the valve springs at $4 each and you've got a solid engine. Took me a couple hours and I'm not all that experienced, shop shouldn't charge too much

 

Thanks again for the replies. I got a line on 04 Hemi. Any issues with the 04's?

 

Aside from the "C-Clips" which plaque all the 3rd Gen 1500s with factory LSD, nope. Pretty solid...