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1st gen cummins advantages and disadvantages

24K views 26 replies 18 participants last post by  RXT 
#1 ·
Before I buy a 1st gen cummins I want to know what problems the cummins comes with when I buy it. What's something good or bad that you wish you knew when you bought your 1st gen? What things do you love about your 1st gen? Thanks for your help.
 
#2 ·
89-91..NO COMPUTER!!! But that also means no intercooler. 91.5 to '93 Intercooled, but has computer.

Suspension was under enginneered for the Cummins. Aftermarket parts have helped fix that. All are prone to rust...hence the millin mile engine and 100,000 mile body saying.

The technology is quite simple though.

That said, I love my '90 D250!!! Very reliable.
 
#4 ·
Anything steel is prone to rust. But yes, older vehicles tend to have rust issues, depending on where the truck lived most of it's life.

I like my cummins for the fuel mileage and power. It's also fairly simple to work on, and modifying the truck for more power can be fairly cheap. But honestly, I love driving something yout don't see that often. I wish I would have known what stuff was going to break on my truck before it broke, but that's been a learning experience. It's part of the experience of being an owner of one of these things.
 
#9 ·
Isn't this the truth :hehe:

I like my first gen over pretty much any other truck out there just because of its simplicity. There isn't a thing on the truck that I couldn't work on or replace if I had too, and there's something to be said about that because that is not the case with many vehicles on the road today. The 12 valve Cummins sounds amazing with a good exhaust, starts every time you need it to, makes good power and is easy to hop up if wanted, I'm definitely a fan! The only cons I can really think of are the not so good turning radius (which I am used to by now so I don't even notice it), lack of room in the rear seat (not a big issue for me), and the rougher than average ride (just part of the fun of having a first gen haha)
 
#8 ·
The reason I asked about prone to rust and where the person that said that lives it that I disagree. from the 80's forward dodge had good rust protection in my opinion. Steel is going to try to it's natural state no matter what you do, but that fact that they are old doesn't make them prone to rust. I live in an area where vehicles that are prone to rust do, and those that aren't last for a very long time. and most 1gen's aren't rusty around here.
 
#11 ·
Roof rot. Questionable electrical system. Hit and miss on fit and finish. Dated brakes, not so great steering. 4wd prone to cracks on steering box mounting area. Rough suspension by modern standards. Windshield prone to leaks leading to floorboard rot. Non lockup automatics that typically don't handle a lot of additional power. Single wheel trucks had a weaker 32 spline Dana 70.

Motor is pretty good though :)
 
#13 ·
yes and no on Dana 70. 35 spline with power loc from factory Dana 70U2 and 5 spd. Started to rust on windshield and leak to the floor. got it bed lined. Rocker panel started to rust and surface rust . got to get her restored... there is few rust bucket driving around .
 
#15 ·
My concerns would be whether the dowel pin had been killed yet and how much tinkering (good or bad) the POs did.

Other than that its the cheesy electrical system (fusible links, lack of relays, etc) but you can improve that as you go.

And the obvious body and suspension issues the others bring up.
 
#16 ·
Plus;Folks that drive the new Ram Trucks want one. They walk over to you @ the fuel island and talk truck.

The negative; Holes in the body.
 
#18 ·
Haha how small are you? I can barely fit my hands in some places, much less fit under the hood with that beast of an engine.
 
#19 ·
Pros: It's sexy and gets the women with the sound and square body; Fuel mileage; It's a goddamn tank

Cons: It's a goddamn tank; It gets the wrong kind of women sometimes because it can haul a "heavier load"; It only does like 75 with 4.10s from the factory and that makes me sad.
 
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#21 ·
Stock 6,300 LB truck with automatic trans, Diesel, 3500 4+4, extra cab, dual wheels 22 to 24 MPG on level ground at 60 MPH. :love: Simple to work on compared to new trucks. Engine does not run on a computer. Computer runs various other items. Most non Dodge made parts are good quality. Engine it OUTSTANDING and easy to increase power. Trucks look cool.

The bad, (and there is plenty) Manual trans G360 too weak and will fail. Auto trans not suited for this truck/engine combo. 2 1/2 first gear ratio not suited for towing heavy weight. Non lockup torque converter creates too much heat. Neither trans suited for increased engine power. Coined lug nut stock rim design is TERRIBLE. Rear duel rims don't self center on the hubs. Radiator is too small. Leaf spring suspension is TERRIBLE and almost non existent and will beat you and the truck apart. Electrical system is questionable.

Lots of time and $$$ can rectify most of the problems. ;)

Dodge made parts are of poor quality.
 
#25 ·
I like the 2wd ride. Even though its rated for 3800-4000#, its not a real heavy-duty suspension IMHO.

The trucks with the 5/8" rear spring eyebolts are a lighter pack - also helps the ride. SRW and lower the air pressure helps even more.
 
#27 ·
These are some of the most durable and dependable engines out there. The only thing stronger is an anvil, and not by much. The only known problem with these engines and it's an easy fix is what's called the Killer Dowel Pin syndrome. What it is, is a small metal pin that's press fitted in the block under the timing cover case. It has a tendency to fall out. It can pass harmlessly into the oil pan or wreak total catastrophic damage. I suspect that at this age, it's been addressed, but have it looked at anyway and have the pin tabbed if it hasn't been touched so it can never fall out.

Not so much of a problem for 1st gens, but for 2nd gens there was the dreaded #53 block. For some reason, all blocks marked with a #53 were prone to cracking under the turbo and external heat exchanger area, resulting in a loss of coolant. Apparently it was a manufacturing defect. The first gens weren't affected, BUT if for some reason the engine was swapped (Which isn't not likely but still possible) have a peek under the injector pump for the block casting number.

From the factory, the 1st gens were rated at 160HP and 400 ft-lbs of torque. By today's standards, this is grossly underpowered, but when it was new, it was top tier factory performance. In reality these engines were actually detuned because the old 727 automatic transmissions that were bolted to them were not up to the power one of these engines could dish out. So that's a really good thing because no matter how hard one of these engines may have been used in it's life, it was never near breaking point (somewhere north of 800 HP) So long as the engine was serviced, they will last a very long time and that means that so long as it was serviced, at the power levels it was set, it's probably got lots of life left in it and could still handle more power if you choose to turn it up.

Any real con would be mostly related to what's bolted to the engine and wether you want to turn it up for more power. The first 400 hp isn't very expensive or difficult to achieve but after that if you want more, it becomes very expensive and much more difficult.

Ed
 
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