[kscarter]

I'm been reading through quite a few posts over the last month or 2 for information on swapping a 4bt into a Dodge Ram 1500. It seems that most posters say the transmission and transfer case from a gasser will not hold up under the torque of the 4bt. If I read the specs correctly, the 5.2L gas has a torque of 300 ft/lbs and the 4bt has a torque of 265 ft/lbs. Just looking at the figures, I would think the transmission and transfer case from a gasser would hold up behind a 4bt if it’s possible to hook them up. I understand the need for a different torque converter due the differences in stall speed. Is it possible to take the bell housing, torque converter, and input shaft from a 47 rh/e and install them in a 46 rh/e? I’ve read all the posts about it costing twice what you originally think, do it right the first time, and so forth and I’m not necessarily trying to be cheap, but the more I can reuse the better.

Any and all responses are appreciated

 

[JimmieD]

Welcome KS!

This is not a definitive answer to your question but may help understanding. A gasoline engine doesn't get into it peak torque until maybe 1,700-2500 rpm. The horsepower doesn't begin to turn on until higher revs.

A diesel produces near its peak torque right off of idle.

So the gasser gets the load rolling with low torque and hosepower, and the vehicle is already rolling pretty well before peak torque is fed into drivetrain. The diesel feeds near full torque into the drivetrain with vehicle at a stand still, so far greater rolling resistance to peak torque.

It's real similar to taching up the gasser to about 3,500 and slipping your foot off the side of the clutch! Rhymes with 'SNAP'! Whole different ball game.

 

[kscarter]

Thanks for the explanation, it helps clear some of the mud in my head about this swap.

In my searching, I read where Ram 1500 and 2500 4X4's both came with the NP241DLD transfer case. (the NP241DHD was optional on 2500) If this is the case, is it possible for me to reuse my current transfer case and only replace the transmission. I was looking at buying a tc from a 1997 Ram diesel that is a 241DLD but if that's what I already have then I should be good unless the spline count is different. Does anyone know if both the 23 and 29 splices where used behind the 6bt.

The gentleman with the tc also has a 47re transmission. From what I've read, I believe I need a 47rh and not the re unless there's an easy solution to getting the re version to work with a 4bt.

Thanks to anyone who can help me along the way.

 

[Diesel Durango]

no easy way to get the 47re to work with the 4bt unless you got money to pay for an ATS controller/valve body, etc. you will want a 47rh and will just need a lockup controller.

Easiest way would be to find a 2500 with a good trans that had been rolled or something, that's how i got my nv4500, it worked well financially after i sold the engine and the rest of the truck that i didn't use. You will have everything you need, plumbing and whatnot too if you do it this way. It would have saved me a LOT if i had done it first instead of when i just swapped transmissions.

you probably won't need to do anything to the TC input, i think both the 46 and 47 are a 23 spline output, should bolt right together.

you can't use the gasser trans because the bellhousing is all integrated, it's not modular like the nv4500. you need the diesel trans to make it work, they are probably governed differently too.

 

[kscarter]

If the truck currently has a 46RE transmission would the 47RE be able to use the same electronic hookups or will it not be receiving the needed inputs from the 4bt that it's currently getting from the 5.2L gas.

 

[Diesel Durango]

exactly, the 46/47RE is all electronic controlled, you might be able to do it, but i have no idea how. The RH series are hydraulic and much easier to work with in this application.

 

[kscarter]

Looking at transmission prices, it seems 47RH runs around the same price as a NV4500. Is one preferable over the over in terms of durability and longevity? Considering this will be mostly driven by my 16 year old son, which transmission has a better chance to survive. I'm going to assume a manual but might go through a clutch or 2. Can anyone who has converted a Ram from automatic to manual tell me if it was difficult or pretty straight forward?
Looking under the dash, it appears there's a pin that can be used to hang the clutch petal and there's a plug on the firewall where the clutch master cylinder installs.

 

[Diesel Durango]

i did it in my durango. you will have to cut a hole in the floor most likely, not sure if there is anything there already in the ram, they did com with manuals, so it is possible. that hole in the firewall should work for the clutch master, and if you can find the pedals to a manual 1500 they should work on that pin, may need a longer pin, depends on the setup.

learning to drive stick on a diesel, if done right, is EXTREMELY easy. I put it in second and let the clutch out and it starts moving... doesn't bog at all, very different from driving stick on a gasser.

getting all the pieces together for either could be difficult without a donor truck, but the manual would probably still be easier. remember you will need all the little pieces though, shifter/throwout bearing/clutch fork, master/slave. it may add up to more, but will most likely outlast the auto.

it really depends on if you want stick or auto.

 

[kscarter]

Thanks for the input. I currently have a VW TDI Jetta 5sp that he likes driving so he knows how to drive a stick and is all for going manual. I think I will start my planning with a manual in mind.

What is the best solution for brakes. I may be wrong but there seems to be 2 ways to go. A power steering pump with a vacuum or a hydroboost. Can someone correctly if I'm wrong and give me the pluses and minuses between to two.

Thanks

 

[averagef250]

If the vehicle requires vacuum for things like heater controls and cruise control the you'll need a vacuum pump anyway so you might as well stay vacuum brakes. If the vehicle doesn't need vacuum at all except for brakes (many do not) you can swap in hydroboost and keep things simple without a vacuum pump if you want.

Hydroboost works a lot better than vacuum brakes.

 

[Diesel Durango]

the +'s and -'s in a nutshell:

hydroboost:
say... PS pump fails, no hydroboost, no steering

hydroboost:
say... vacuum pump fails, no vacuum boost, still have steering... depends on how the vacuum pump fails and your setup. with the dodge ram setup, in theory the vacuum pump could completely fail and the PS pump wouldn't work since they are off the same drive gear on the engine. make sense?

say... PS pump fails, still have brakes


there are lots of variations, but with basic numbers, you have slightly more redundancy with vacuum boost than with hydroboost. Some people say that when you brake hard steering doesn't work so well, no clue about this, but seems possible. if you are used to vacuum brakes, the dodge PS/vacuum pump combo will work like stock.

 

[tate]

If you can get your hands on the dodge PS/Vac pump, keeping the vac brakes would be the easiest. I don't know how much the hydroboost setup is worth, but you already have vacuum brakes that work half decent. With my dodge, when the engine is off, its hard to hold the truck on an incline with just the brakes.

If you have a manual and the engine stalls, you can keep it in gear and cost and will still retain steering and brakes. Thats one con to the auto. That, and if its gonna hold decent power, you're gonna have to spend some coin to make it live. With the NV4500, you'll need a clutch and thats about it. Very robust trannies.

 

[kscarter]

I have a few more transmissions questions.

1. Seems most people agree that the 47rh/re transmissions are a weak spot with Dodge Cummins diesels. I would expect putting a 47rh behind a 4bt would make it more reliable since it would not be pushed to limits that it sees behind a 6bt. Would anybody agree with me on this.

2. Does anyone know if a 47RH will bolt right in place of a 46RE without any modifications to the frame or transmissions support.

3. If I do decide to go manual, what is involved with hanging an NV4500 in place of a 46RE besides cutting the hole for shifter.

Thanks.

 

[Diesel Durango]

not a ram, but i put the 4500 in my durango, should be a bit tighter by comparison. You will probably have to shoe-horn the 4bt in there more so than the nv4500, if you want to keep it 4x4 w/o a lift.

I would guess the nv4500 and 46re are about the same length, the nv may be shorter even. I am still using the stock drive shaft, though it is on the short side. You will probably have to modify the crossmember, but maybe not...

Most people regard the 47RE as being more problematic than the earlier 47RH, i would expect the 47RH to hold up fine behind a 4bt as long as you get it set up properly.

 

[sirhannick]

3. If I do decide to go manual, what is involved with hanging an NV4500 in place of a 46RE besides cutting the hole for shifter.

kscarter, I too am looking into doing a swap into a Ram 1500, but a 2WD. I have decided on converting to NV4500 instead of 46RE. The NV5600 will just weigh and cost too much.

Maybe we can collaborate on this since we both have the same truck minus the 4WD. I will be doing the 4BT swap for a class project at university.

 

[kscarter]

sirhannick - sounds like a good idea. I will need all the collaboration I can get. I will be picking up my 4bt this weekend. Still need to transmission and all the extras. When will you be starting your swap. I'll send you a PM with some of my plans and thoughts.

 

[MikeC870]

RE: RAM 1500 4x4 Swap

Hey Guys, I'm new to the forum(lots of mistakes will follow). I just got one project running, but not finished. It's a 1996 Dodge 1500 Reg. cab shortbed, 4bt 518 non-lockup. CPL 0986, intercooler off a 93 Ram 2500. 29 inch tall tire and 3.55 gears. The best mileage i've gotten is 24.5. I was hoping for more. Some say that the 6bt's get low 20's, so what gives? Any help would be great.

 

[kscarter]

I know this is sort of like putting a jigsaw puzzle together and when you change one piece, you most likely will need to change other pieces. Is it possible for me to use a gas model NV4500 if I use a flywheel from a gasser? (will a gasser flywheel fit?) I now have my 4bt at home and it has all the chevy parts and adapter which I will need to convert to dodge. I figure I need to get the NV4500 first and then match the pieces around it since their prices seem to be at a premium. If I were to find a good price on a chevy version, how hard is it to change the input and output shafts and is that all I would need to do? What about converting from 2wd to 4wd. If I know the cost and effort to change one version over to another, I could expand my search.

On another note - is it possible to crank up the 4bt for 30-40 seconds while out of the truck. Would be nice to hear it run before I start the journey.

 

[mastermoparman]

imo your best bet would be to change the input shaft on the nv4500 to the diesel fers and use a 6bt adaptor plate and bellhouseing and fly wheel/clutch. easyies way. besides i think the bolt pattern i diff on the gas/diesel flywheels

 

[moparguy]

MikeC870, would that be Jonesboro, AR? My first guess is the non-lock up 518, along with the tall tires and 3.55s are hurting your mileage. I'd bet your converter is making lots of heat due to slippage.

And yes, lots of 12 valve trucks can and have made low 20s mpg, however that's usually under constant cruise conditions running 60 or so. My 4.10 geared 95 3500 4x4 has hit 20 1/2, but with the new diesel and big winch bumper, I'm down to 18 on a good day.

Good luck,

RJR