Cummins Bronco and the D44

[pmctighe]

I have a post on the Cummins board that has created some unexpected discussion about whether I should use a D60 instead of the D44 on my project. I would like to hear from you guys and gals out there that have done the swap or know someone who has and find out how the D44 has held up. My plan was to use and EB or other narrow housing with axles that use the larger u-joint. If necessary I could get the 78 F150 hdd44 housing and narrow it. I really would rather stay away from the d60 because of the expense and weight. Anyways your thought and experiences are most appreciated.

Patrick

 

[Slick]

I would say it depends on how you are drive'n it. If it's just light trail and road drive'n the 44 will be fine.

If you plan to do moderate trail drive'n then get some beefy axels and you should be fine.

If yer do'n some high torque climb'n or heavy wheel'n the GET THE 60.

What breaks axels is the jerk of sudden traction when the wheel is turned, so if you kreep through everything and never HAMMER you way through an obsticle, yer likley to be fine... BUT as you are almost stuck it's AWFUL hard to keep yer foot off the floor!

I think there is a lil bit of homer simpson in all of us that thinks you can get un-stuck from anything with a WHOLE LOT OF FLOOR'n! THA's when ya snap the $$ metal stuff ya never want to break!


...but I digress

 

[COBlu77]

I got to drive a Cummins powered Bronco with a D44 and I think it's matter of when not if you'll break something. Can you say TORQUE!

 

[Apogee]

You're worried about weight and you're putting a Cummins diesel in your rig...I don't care who you are, that's funny there.

Without more info with respect to gear reduction, tire size, and how or where this thing is going to be driven, any recommendations are pretty much meaningless. I'm still having a hard time believing you're worried about a couple hundred pounds of low weight considering the beef you gain with it. I wish I had a 60...and I'm not running no Cummins.

 

[Broncobowsher]

I would say it depends on how you are drive'n it. If it's just light trail and road drive'n the 44 will be fine.

If you plan to do moderate trail drive'n then get some beefy axels and you should be fine.

If yer do'n some high torque climb'n or heavy wheel'n the GET THE 60.

What breaks axels is the jerk of sudden traction when the wheel is turned, so if you kreep through everything and never HAMMER you way through an obsticle, yer likley to be fine... BUT as you are almost stuck it's AWFUL hard to keep yer foot off the floor!

I think there is a lil bit of homer simpson in all of us that thinks you can get un-stuck from anything with a WHOLE LOT OF FLOOR'n! THA's when ya snap the $$ metal stuff ya never want to break!


...but I digress

That's about how I would look at it as well. Depending on how it is used/abused it can range from lasting forever to not making it out of the driveway.

 

[Dieselnutz]

I think a daily driven trail Bronco on 35's or smaller will be fine with the D44. That's my plan too. Don't get me wrong I would love a D60 but way to expensive around here.($1000 up). I just don't plan on holding it too the floor in the rock's. I don't want to spend my time and money building a Bronco and beat it to death! The so called D60 under my 7500lb Dodge holds up to twice the torque any 4BT will put out. And most F250 powerjokes have D50's with the same size ring gear and inner axles as a D44 under them!?:? The D44 will be fine.

The 9 inch will be too with the right parts. There is a guy here running around in
a sweet 69 chevy shortbed with one. I saw it hit nearly 1200ft/lbs on the dyno with a 6BT. But it does have major traction problems!

 

[DirtDonk]

Other than what was already mentioned, you could truss the axle housing to help fight any added flex caused by the extra weight of the Cummins.
Or are we talking about a smaller diesel engine? I'm not that familiar with them, so I'm "assuming" a big six-cylinder like out of a Ram or something.
If so, then a truss can at least help reduce flex, which reduces wear and tear on the axle components.
If it's a four-cylinder or something like that, is there any weight change at all?

Paul

 

[Preston]

I think the cummins 4bt weighs about 750lbs. Is that about what a big block weighs?

Preston

 

[Broncobowsher]

Other than what was already mentioned, you could truss the axle housing to help fight any added flex caused by the extra weight of the Cummins.
Or are we talking about a smaller diesel engine? I'm not that familiar with them, so I'm "assuming" a big six-cylinder like out of a Ram or something.
If so, then a truss can at least help reduce flex, which reduces wear and tear on the axle components.
If it's a four-cylinder or something like that, is there any weight change at all?

Paul

A 4BT or 4BTA is the same engines as the 6 cylinder diesel engines in the dodge, but they left left 2 pistons and cylinders out of the block. So it is just a 4 cylinder version of the big dodge diesel. Leave out 2 pistons, rods and 2 pistons worth of metal in the block, crank and head, so they are a bit lighter. By no means lightweight, just not as heavy as the 6. They were sold as a retrofit for gasoline engines in big box vans.

 

[swa0330]

I can give you my quick thought. I used to think that I had to have every single part and plan to perfection in building my rig before I could start. The reality is that there is nothing better than simply being up and running and adding or changing parts as needed afterwards. I have a 44 and will just run it and see what happens. The torque is a factor with this motor, however a 351 has a lot of torque also. All in all, run what you have for a while and save for a built D 60 while you are out. Unless you are wheeling the living shit out of your rig on rocks, you'll manage for a while. By the way, I would put my money on a 35 spline 9 inch over a Dana 60 rear any day. The 9 inch is the best rear end out there in terms of handling torque output and having better pinion bearing support than a D 60

 

[pmctighe]

You're worried about weight and you're putting a Cummins diesel in your rig...I don't care who you are, that's funny there.

Without more info with respect to gear reduction, tire size, and how or where this thing is going to be driven, any recommendations are pretty much meaningless. I'm still having a hard time believing you're worried about a couple hundred pounds of low weight considering the beef you gain with it. I wish I had a 60...and I'm not running no Cummins.

It is not just the weight under the truck, it's the weight when handling and the expense of d-60's when in my opinion I don't think there necessary. I posted this hoping to hear from some of the guys who have done the conv. to get their experience as well as the general crowd. It seems to me d44 has been used from the factory in equivalent applications. I am probably going to source a HD reverse spiral and shorten it. To do that with a d-60 is much harder and expensive.

As far as the rear I am using 31 spline moser axles in a big bearing rear. As I am not rock crawling I think this set-up will likely meet my needs.

However I would still like to hear from someone with first hand experience.

 

[swa0330]

I have firsthand experience although limited drive time. Nothing has broken yet. The 1st wheeling trip on the 21st should tell more. My only concern with a high pinion D44 is oilpan clearance. The regular 44 clears it with about 4" of lift or more. If it was high pinion, I know the driveshaft would hit the pan, even with the lift. Also, the only other bronco guy who even posts on this board that I can recall with a running 4BT is DogDiesel. Maybe you could PM, because he doesn't post very often.

 

[pmctighe]

DogDiesel Thanks for the reply,

Too everyone thanks for your input. I have been vacillating between the EB housing with upgraded axles and the High pinion. This helps a lot. I'll be trying to figure out clearance issues and make my final decision.

Further discussion is still appreciated.

Patrick

 

[pmctighe]

http://classicbroncos.com/forums/showthread.php?t=103853

%)

No apology needed - Thanks for your help and for defending my family and the freedoms we enjoy.

God Bless you and your family

 

[Scotty]

Just a thought,
I remember Miley (4BT conversion a couple of years ago) writing in one of his posts that he was uncomfortable with the stability of his rig when running Early-Bronco width axles. As I recall, he had 4.5 inches of lift to clear the engine's oil pan, but the extra weight combined with the added height really made him want full-width axles and perhaps even wider tires. SWA0330 might remember better than I do.

DogDiesel, I didn't see in your post if you're running a high pinion D44; stock (or even + 2.5") springs and modified oil pan suggest a standard, low pinion D44. Can you confirm?

Thank You,
Scott

 

[swa0330]

Just a thought,
I remember Miley (4BT conversion a couple of years ago) writing in one of his posts that he was uncomfortable with the stability of his rig when running Early-Bronco width axles. As I recall, he had 4.5 inches of lift to clear the engine's oil pan, but the extra weight combined with the added height really made him want full-width axles and perhaps even wider tires. SWA0330 might remember better than I do.

DogDiesel, I didn't see in your post if you're running a high pinion D44; stock (or even + 2.5") springs and modified oil pan suggest a standard, low pinion D44. Can you confirm?

Thank You,
Scott

First off, As I continue to stray away from all of the 4BT "Miley-isms" that I used to believe were somewhat true, all his advice usually was bad advice based on nothing at all. I am finding that out by reading on 4btswaps.com a number of his tips and suggestions were founded only on what he would do rather than what works. I am finding he was someone who talked and typed just to be heard.

As for his rig, he never believed in dual shocks, always swore by rear inboards and wondered why the thing was scary. Call me a shithead if you want but I cannot stand rear inboard shocks for anything that is ever driven on the road. That was half his problem. When I set my rig up, I called Jim Cole and said what I was going to be doing. He said to go with dual shocks at all corners. Ask those who have ridden in my rig, it is definitely not unstable. It all depends on setup is what I say about that.

I would think stiffer coils or shock valving would be way more beneficial than the extra 4 inches of width on an axle. But back to the original question, I believe that unless it is a wheeler, you are plenty fine with the stock Dana 44. If you aren't wheeling and worry about the weight, then I would pay $200-300 max to a shop to truss the shit out of the 44 rather then the $1200 plus labor time to swap in a Dana 60.

 

[Scotty]

Call me a shithead if you want...

Wait a minute, I'm not calling anybody anything!

I was just looking for a little clarification from someone who's going through it with the intent of actually keeping and enjoying the truck. I have been following 4bt conversions on here for years now and hope to tackle one myself someday, if I ever get through the punch list for my house.

I too believe that the 60 is overkill for a daily driver. The 44 shouldn't have trouble with the extra weight. I see rigs with Dana 44s all the time carrying heavy-duty bumpers and winches that combined weigh more than the variance between the diesel and a 302. You shouldn't have any problem.

I think we can all agree that the wife's approval is paramount. If mama ain't happy, ain't nobody happy.

Scott

 

[pmctighe]

swa0330 Thanks for chiming in I was hoping to hear from you, and as soon as I get the diesel ready I will be calling.

Dog diesel as always I appreciate the advice that you and SWA provide as you guys are the pioneers and I'm trying to learn from those who have already been there.

My preference is to run 2'-3" of suspension lift followed by hopefully 1' of body lift if I can. Emphasis on if. I am Looking to run 32"-33" tires and use as a daily driver. It seems prudent to upgrade the axles to use larger ujoints in a D44 if I stay on that course. High or low pinion will depend mostly on available clearance, second the option of using a HD D44 for a little stronger housing if there's room. Obviously motor mounted height will play a role.

With all of that said it sounds like the consensus given the daily driver aspect is the D44 will be fine. High or low pinion is still undetermined until the motor mounts have been worked out. I will keep you posted on my progress an as always appreciate the response.

Thanks to all,

Patrick

 

[swa0330]

The consensus I have heard on motor mounts is that the liquid filled like JBFab is using are the softest. Steve Graham (one of the earliest 4BT guys) figured out that drilling a few holes in the 6BT motor mounts in the rubber cut vibration considerably. I will tell you that the vibration is only evident at idle based on what I can tell. Once up and moving, the thing purrs like a little kitten. I will send you a diff pan shot sometime. If you go with 3.5" of lift with 33's you should be fine. I have about 2.5" of clearance between the diff and the lower rear left part of the pan.

 

[pmctighe]

The consensus I have heard on motor mounts is that the liquid filled like JBFab is using are the softest. Steve Graham (one of the earliest 4BT guys) figured out that drilling a few holes in the 6BT motor mounts in the rubber cut vibration considerably. I will tell you that the vibration is only evident at idle based on what I can tell. Once up and moving, the thing purrs like a little kitten. I will send you a diff pan shot sometime. If you go with 3.5" of lift with 33's you should be fine. I have about 2.5" of clearance between the diff and the lower rear left part of the pan.

Are you running a stock or high pinion D44?