Cummins 5.9 guys, you happy with your swap?

[pcoplin]

I swapped in a Dodge 5.2 into the wife's 85 Wagoneer. But been thinking of getting her a new Grand Cherokee or Durango, and takin git for myself. Do a SOA with custom front springs, 5.9 diesel, and 48RE.

You happy with the swap? Would you have done something different? Thanks!

[Lumpskie]

Bump!

I'm just starting my research on swaps. I called up Aaron Reeves, who has done a number of Cummins swaps, and he steered me away from the 4bt because of massive vibration. He said that the 6bt vibrates way less and gets the same gas mileage. (mid 20s) My question is: Would the 6bt be a good option for a daily driver/tow rig application? You guys that have done the 6bt, how happy are you with your decision? (Both with picking the 6bt and deciding to go diesel in general)

Thanks for putting up with my noob questions,

[will e]

Well, look at how many people posted up they were happy!

I am a noob to diesel swaps but have seen a few include at least one 6bt. The main problem, as I understand it, is the 6bt is really heavy and to do it right you need to beef up the front suspension and frame. This may include a larger axle.

As of late the Vortec swap seems to be in fashion. I think overall it is less complicated. You get a nice powerful engine with a nice OD transmission. You would be able to tow with it and get better gas milage.

[Lumpskie]

^This sounds interesting! Any idea on the gas mileage and availability of a 5-speed?

(I'll search the internet too)

[will e]

Search the site for Vortec. The results are a little cluttered but there are a couple of good build threads with A LOT of detail. I think some will include results.

We are never going to get great gas milage due to our aerodynamics.

[Lumpskie]

^Awesome. I'll check that out.

I'm not looking for incredible gas mileage, but 20mpg on a motor that could tow 5000 lbs without sweating would really make me happy!

[Mudbull]

Im a big fan of the LS engine, but for me i wouldn't want anything but a Cummins in my truck; im planning on doing another conversion hopefully in the near future. The thing with diesels, if your towing a lot, is that your fuel mileage doesn't drop off as quickly as in a gas truck. In my donor Ram I was getting 15-17mpg towing 5000lbs. In my Kaiser not towing anything im getting 20-23mpg easy.

The cummins is a very heavy engine (~1200lbs), you would need to reinforce the front end and get something like a dana 60 for the front. It isn't a light duty engine that was thought up for the consumer market, its a heavy duty diesel engine. With that being said, it is not the most refined of rides-its loud under the hood (mechanical noises, injectors...) and rattles worse than any v8 at idle.

For an easy swap that will be good around town you may want to just go with an LS, let me know if you have any other questions.

[243]

I never had a 12V but two 24V's for about 6 years, loved them both.

The pigs were just hell on the D60 ball joints, track bar and to a lesser degree tie rods, I would not want any less than a D60...

I will be happy with an LS in my Chero but that smooth and quiet 12V is TEMPTING!

[The PIG Smith]

Everyone I know and have spoken to have loved their Cummins 6BT and 4BT swaps.
However, I do know of some folks that Diesel is not for them.

Tad told me once when I asked him about SOA for one of my rigs, that I need to ride and then drive in a SOA rig before I decide if that is way I wanna go.
He went on to say that SOA rigs are not for everyone.

Same advice applies to Diesel swaps.
They are not for everyone.

[243]

Put me in the love diesels crowd, I don't mind the smell of raw diesel and far prefer diesel exhaust to gasoline exhaust.

My wife used to complain I didn't pay enough attention to her, I said, "put a dab 'o diesel behind your ears", she was not amused...and she is my EX now

[Lumpskie]

So, you guys, I've got another noob question for you on the subject. I understand why you need to beef up the front springs for the 6bt but why do you need a beefier axle up front? Wouldn't the torque from the motor be loading the rear axle?

[Gumby]

So, you guys, I've got another noob question for you on the subject. I understand why you need to beef up the front springs for the 6bt but why do you need a beefier axle up front? Wouldn't the torque from the motor be loading the rear axle?

I love my diesel and if the gods permit I too would do a swap only with the CRD though, they idle and vibrate much less. About the axle, have you ever seen one of those power wheels after the big kids drive them too much? Same result with the Cummins in a "light" vehicle like a FSJ.

This swap is not for everyone but it is one he'll of an improvement if you do it right.

[will e]

It's the physical weight of the engine that the front axle is trying to support that will be the issue.

[tndonor]

Ive had two FSJ Cummins rigs.

My first was a 1980 J10 with a 4B. The only time they vibrate more IMO is on shutdown. Of the dozen or so conversions I have been around, the "vibration" issue came from motor mounting choices. I used a hydraulic isolating mount. It vibrated no worse than the 6.2 GM Diesel that was in the J truck before that.

My current truck is a M715 with a 6B. It doesnt really vibrate but is loud as the military trucks are single pane metal everything. No sound dampening. Its also sprung over, has 39 inch tires, etc so Engine vibration was never on my radar so to say.

Most people who dont like the Diesel dont have needs/goals that Diesel will fullfill. Putting one in just because or thats what the cools kids are doing will disappoint everytime. Perhaps posting what you hope to accomplish with a powertrain swap and both sides of this coin can chime in and lend some more pointed informaiton and advice.

[Lumpskie]

I see what you're saying about the weight of the engine... that just never occured to me! (I come from an import vehicle background and I hand carried the Acura motor for my last swap!)

I'd love to hear more opinions on what you guys suggest for a swap, but don't want to clutter this thread. So, I'll start another one. Post over there and give me all your opinions and experiences!

[Iceman0502]

Ford used Dana 44's under thier 7.3 diesel 3/4 ton trucks back in the 90s, maybe early 90's. They were full width 69"ish and equiped with 8 lugs and bigger brakes.

Waggoneer axles are narrow width so i would think it is less span to bend and can be converted to 8 lug with big brakes.

Aren't Dana 44 ball joints all the same and it doesnt matter the vehicle manufacturer??

There are still untouched ford diesels driving around with original ball joints.


Also J20's are considered 3/4 ton trucks. They use a front Dana 44 front which is the same as J10 D44. J10/20 front springs could have front springs with a load rating or 1400 lbs each (total 2800 lbs). Stock wagoneer springs are 960 lbs each (total 1920 lbs). Thats a difference of 880 lbs, which is about the difference from the stock 360 (600 lbs?) to a 6BT (1200 lbs?).

Just think about how many J10/20s are driving around with plow mounts and overhead racks, etc. Also chevy put a 10 bolt under thier 3/4 ton suburbans with 6.2 diesels.

I personally think the Dana 44 would hold up for daily driving, towing, camping activities. Something larger will be necessary for offroading.

[tndonor]

As far as weight... I only know the Cummins side of things.

A 4B is about 750 pounds, a 6B just south of 1200 pounds. If you add a bumper, winch, etc......it adds up quick. Larger front axle is to adequately support the weight more than it sends the power to the rear.

[husker77]

Ford used Dana 44's under thier 7.3 diesel 3/4 ton trucks back in the 90s, maybe early 90's. They were full width 69"ish and equiped with 8 lugs and bigger brakes.

I am not positive but anything with the diesel would be a f250 or f350. The f250's would have a ttb dana 50 under the front, the outers are the same(or close to) as dana 60's. Any f350 would be a dana 60, except for a few I think had dana 50's.

[Iceman0502]

I guess besides the choice of axle.

What did everyone do with there registration? Is it worth changing gas to diesel? or becuase most of these trucks are before OBD2 does it even matter with no emissions? Keep the gas registration and drive the diesel?

[tndonor]

Registration is largely a function of where you live. Check your local laws regarding engine swaps, emissions, etc. There is no panacea answer unfortunately. It can even vary within a county