Bronco Diesel Swap! HELP!!!

[Agnem]

There is great belief in the Bronco community that the stock axles won't handle the diesel. Where this comes from I have no idea, as guys have been hanging snow plows on the front of stock Bronco's since forever, and the added weight of that, and the distance it hangs out on the front, surely amount to the difference in weight between a 350 gasser and a 6.9 or 7.3. I've been running on the stock axles for over 2 years now, and have no problems with that at all. I don't go 4 wheeling but those who have been to my house will attest that Oakwood Drive is worse than most trails. I run 33" tires. Now if you want to go bigger than that, then that is enough reason right there to want a heavier axle. Otherwise, the weight carrying capability of the stock axles are fine. The other fallacy concerning the axles is that the gears won't take the torque of the diesel. When mine had the 302 in it, I could squeal the tires, same as I can with this diesel. Once the tires are spinning, I don't see a difference, do you? Now if you plan on towing more weight than the Bronco's advertised capacity, well then there you go. But you'd need an axle upgrade regardless of what motor was in it. Now I have had plans for a long time of upgrading the axles to 8 luggers just for the sake of coolness, and standardization of spare parts in my fleet, but since it's mostly a cosmetic and convienence change, I keep putting it off.

 

[JLep]

That is great info. I thought they would work, since I am a fairly conservative driver and am not planning on off road or tires any larger than you have. I talked to the auto tech guy here at school and he said 3.73 or 3.50 gears (not sure of the exact numbers) would give me decent take off in first gear and a good rpm for cruising on the highway. What do you think? Very encouraging news once again. Thanks!

 

[FordGuy100]

With 3.54 gears and my T-19 tranny, I can take off in 1st gear without giving it any throttle, it luggs a little if I go a little to fast, but its a diesel, they can be lugged.

 

[JLep]

So, I could lower than that even? Down to 3.10, really utilize that torque to get it rolling. I would like to gear for 65 mph at around 1800-2000 rpm's. I am planning on a turbo kit. Is that necessary, or can I open up the intake, bring the exhaust together and put a flow through on their with no cat? Does the turbo make a big difference? This is great info, I really appreciate all the help.

Another thing, I spoke with the Auto Tech. teacher this morning and the kids are going to rebuild this motor before it goes in, anything in particular I should do? Should I install head studs? Where do I get a rebuild kit? What else would be beneficial while it's torn down? I am thinking I will a pretty darn nice vehicle when I'm done.

 

[FordGuy100]

Are they going to machine it, or just tear it appart and reasemble it with new parts? I would put studs in just for the piece of mind of it. Other than that just have them go through it and put all new bearings and everything, turn the crank and all that kind of stuff. Somebody should chime in as to what to do to get a good running engine.

I think the turbo at highway speeds will net you better fuel economy because with the boost it will deliver, even if it was 1 psi which I figure is what it would make, maybe 1.5psi, that will give you a more complete burn of fuel. If you have a turbo, run it without a muffler or cat, this will get you less backpreasure=better fuel economy.

1800-2000rpms at 65mph would be about a ZF-5 speed and 3.55/3.54 gears with 33" tall tires, or at least it should be close. There are some speed and rpm calculators on the net.

 

[cleithau]

I mean assuming they know what they are doing they should tell you what you need to do, not you telling them what to do. After measuring and examining the internals of the engine they should tell you if it needs to be machined in any way or if everything is within spec. You can get some idea of what you might need to have done by its running condition but you won't really know till its apart.

 

[Agnem]

The 6.9 is way plenty motor for a Bronco. With a turbo it would be like a freakin' sports car. I wanted the sound of a big V-8 and dual exhaust, so I'm not going to ruin it with a turbo (I have two other turbo'ed trucks already for my whistle fix). But if I build another one, I very well may turbo it. 3.54 gearing is great for up to 60 MPH, but I want to go faster, and get better fuel economy, so I'm currently looking to put a GV behind the C6. If I had an E4OD or ZF5 I think I'd be content already.

 

[riotwarrior]

The 6.9 is way plenty motor for a Bronco. With a turbo it would be like a freakin' sports car. I wanted the sound of a big V-8 and dual exhaust, so I'm not going to ruin it with a turbo (I have two other turbo'ed trucks already for my whistle fix). But if I build another one, I very well may turbo it. 3.54 gearing is great for up to 60 MPH, but I want to go faster, and get better fuel economy, so I'm currently looking to put a GV behind the C6. If I had an E4OD or ZF5 I think I'd be content already.

YA HA A freakin sports car...or better yet build it into a monster something like this here cummins jeep conversion! http://www.youtube.com/watch?v=Fh45CBDc5iw

 

[FordGuy100]

YA HA A freakin sports car...or better yet build it into a monster something like this here cummins jeep conversion! http://www.youtube.com/watch?v=Fh45CBDc5iw

Or how about a powerstroke in a jeep http://www.youtube.com/watch?v=919TgDu43qI

 

[Diesel JD]

What transmission is going behind this Bronco Jlep? Your T19 or something else?

 

[Crumm]

F350 Bronco

Another possible option to get a diesel into a Bronco is to transplant the Bronco body onto a Diesel equipped frame. I have been thinking about this swap for years. On the North slope there are many trucks with low miles(they do have high engine hours)but beat up body's. I was thinking that putting a bronco cab on a F350 frame would make a tough unit. A guy could even use the firewall and dash out of the diesel truck so that all the wiring and such is already there. I was thinking mid 90's PowerStroke so the wiring would be nice to keep. IDI would not really matter as they have much less wiring. Just another option.

 

[JLep]

I was leaning towards the turbo, I like the sound of the straight pipes and I've heard that they do increase mpg's. I'm going to put a ZF5 behind the motor, I wasn't aware that my truck had a T19 (4speed). Could I divorce the transfer case? Highway and light off road abilities then. If I do put in the ZF5, could I use 3.10 gears in the rear? What do you all think about that? Like I said, I'm not looking for a speed demon here, I want the torque and power to be used to move the vehicle under normal conditions, normal driving, normal load.

Guy, you said you have 3.53 gears on a T19, no throttle needed to get it moving in first gear. Well, with that said, i'm thinking I could go down further, like I said, i don't want a granny gear here. So, I would just have to give it gas to get her moving.

The motors not at school yet, as for suggestions, that's all they are for now. The Auto Tech instructor is a great guy, they've done quite a bit of work for me and it's labor free. Good benny since I'm and instructor. So, the kids will take it down and he will work with them and they will make suggestions as to what is needed. So, with that said, where can I find a rebuild kit and head studs?

 

[JLep]

Got the truck all lined up to pull the motor out. The project is underway today.

 

[towcat]

I just picked up on this thread today. Only thing I have to add is be sure the heads are untorqued by proper bolt sequence. Otherwise you will have a very expensive cracked head repair job in front of you. My personal rule of thumb is that if the motor is not showing signs of any issues, leave it alone and throw it in. More than once I've seen a well intentioned re-gasket and freshing up job turn into a nightmare.

 

[JLep]

Thanks for the advice. Perhaps I will take that and wait till it needs rebuilt. Good advice.