Install AWD rearend in Grand Caravan

Can find this info NOWHERE. - Can you help please? - I have a 98 Grand Caravan WITHOUT all wheel drive (AWD). Can i install AWD in my existing van ? - I just want to replace my existing rearend with an AWD rear end. I do not need to install the drive shaft from the engine. It seems to me that the uniweld body should be designed to accept either the AWD or NOT (when assembled at the mfg., by order). It should not require a unique body construction. I need the transfer case and wheels. I want to replace the drive shaft with an electric motor shaft (batteries, and controller) to provide a parallel hybrid. I will use the conventional ICE in NEUTRAL to maintain power brakes, steering, etc. - I will use the electrical motor power to the free wheel rear end to provide wheel torque in town driving (95% of my driving mileage). - Someone said, “Just buy a van with AWD!” - I know my vehicle and do not want to replace it with a pig in a poke and a hundred other things wrong with it. - Thanks for your help.

Gary Blessington.











Two easy steps:

  1. sell your vehicle
  2. buy one with AWD

Done!

Gary,

If you are going to install electric motors in the rear axle, the first step is to get an electrical power source. The alternator just doesn’t put out enough power by itself. You will need a “generator” built into the drivetrain - like the current hybrids do.

If you follow the current practice in hybrids, the ability of the engine to supply electrical power is slightly less than the peak power needed, so they use a large battery to store power when it is not being used - and then make it available when it is needed.

Yup, your minivan is not only NOT designed to accommodate the generator, but it isn’t designed to house the battery. You could do all that, but the work needed to accomplish that is tremendous - well beyond the average mechanic.

You’re going to spend tens of thousands of dollars to re-design and rebuild your GC.

If you’re lucky it might work as you think it will. (What’s going to power the electric motors?)

If you’re unlucky you’ll be out tens of thousands of dollars and have nothing to show for it.

It would be much less expensive, and probably less trouble, to trade your van for one with AWD.

You are asking folks who fix things if you can make a major modification to your van. Where are you going to mount electric motor(s)? Where are you going to put the power source, batteries? And countless other engineering questions that all go into making this work.

If you are an “inventor” with a lot of tools, such as welding, fabrication, etc. you might be able to do this. The costs will be high. The van would be largely unusable with motors, batteries, and wiring taking up most of the rear cargo area.

To source an AWD rear end just start with a good salvage yard search. You will have to take all the braking and wheel hardware as well. Once you start this project be ready to deal with lots of issues on the fly. You’ll need another vehicle to use for the 6 months it will take to complete the project.

Re engineering something that was never designed for is the most unrewarding and daunting task you can imagine. That’s why remodeling is often much more expensive than building.
Eventually, when “legos” take over car making, maybe. “Twotone” has the only worth while solution for now.

Try http://car-part.com

The parts list will only say FWD or RWD - choose RWD and you’ll come up with AWD rears.

I’m not going to tell you how to spend your time and money. If you want to give something a whirl, then have at it.

I will actually suggest buying an AWD though. I do get what you mean about knowing your own van. So I’d not buy it as a replacement, but as a parts car. The engines in those vans tend to be very good. The transmissions not so much. I’ll bet there are a few around up for sale cheap due to failed transmissions (though the AWDs were not all that common so you’d likely end up needing to haul one in from a distance).

So if you get it as a parts car, you’ll have a complete look at the rear axle set up before trying to take it all apart, but you’ll have a full load of all sorts of parts from body panels & doors to sensors and such. If you find a disabled '98 AWD the whole van would likely only be a couple hundred extra $$.

I’d say that the bonus to that is if you do try the whole thing and don’t get it to work out you can recover a lot of your own costs on parts, scrap, etc. If you buy only a rear you’re holding less value if things go wrong.

Dude, it aint that simple.

Anything’s possible with an unlimited budget, your own tv show, and every fabrication & production tool known to mankind.

otherwise ( per twotone )
sell that car,
Buy an awd.

This was my favorite answer. It still did not answer my original question. Everyone is being really helpful suggesting that i do this, or, that, or don’t waste money, or WHATEVER ! - But no one has answered whether or not i can put and AWD rear end into my van. - It may very well be that no one reading the question really knows the answer. - (So, they are substituting other stuff that is not related to the question.) - That’s O.K. - Click and Clack would probably have to go to the engineers to find the answer. - Maybe the engineers will talk to them, but they won’t talk to me. - (Wonder why ?) - SIMPLE ! - Just buy and AWD ! - (Duh !) - That does NOT answer the question. Sorry Guys. ! - I give up.

I misread it and thought you couldn’t find a rear for it.

It seems to me that you should be able to get a good idea about this from repair manuals. If you were to buy a Haynes or Chiltons it will likely cover both AWD & FWD vans. It won’t tell you whether or not you can swap rear ends or how - but you should be able to get a good idea of what is different. I’d just start with a diagram of the rear ends.

It is likely that no one really would know enough to just say “yes” or “no” or “here’s how” b/c it is a maverick thing to do. I.e. an actual mechanic in the normal course of working on cars would not even think to do such a thing. It is unlikely to be workable even if you can bolt on a different rear.

But if you’re determined to do it, then go for it. If you’re interested there are a lot of really smart and knowledgeable Dodge van people here: http://www.allpar.com/forums/

I feel somewhat confident that no one here has ever tried to install the drive train as you hope to do. And I am certain that no one here has successfully done so. Certainly it is possible. Do you have a lift? How about a transmission jack? An oxy-acetylene torch? A wire welder? Several here, myself included, have done some re-engineering on vehicles with varying degrees of success and the above mentioned equipment was readily available plus an outrageous array of tools and other equipment and a store room full of miscellaneous nuts and bolts, sheet metal, angle iron, etc., ad nauseum. It would seem that the efforts of some to be kind in their efforts to discourage you from wasting time and money brings you to denigrate their intelligence. Well, bring me the van and $50,000 and I’ll install everything to my satisfaction and refund any cash left over. So don’t give up. Just get that cash together.

Thanks again, friend. - I have the Haynes book and referred to it first of all, long before my questions began. - It says absolutely nothing about the AWD van model. It shows, clearly and shortly, how to remove and replace the rear ‘axle beam’ (so called). - Doing that is no big deal. (Neither, should be, dropping the rear axle of the AWD.) - (I hope you see where my question is coming from.) Drop one, put another in. - It’s not rocket science (IF IT CAN BE DONE). - That’s why i asked the question. - Probably, the Manufacturer’s maintenance manual has sufficient information to answer that question (at least by looking at corresponding photographs). But i do not have that manual available. - I am well aware of the other costs related to the project. Motors, batteries, and controllers are not ‘cheap’. (But they won’t run 25,000 or 30,000 dollars - if an electric van hybrid EVER sells that cheaply !) - Try, maybe, 40 to 50 K ! - I also don’t want an electric teeny weeny that’s going to need new batteries in three days anyway. - My van doesn’t care if it’s running with its present rear end or a substituted AWD rear end (with no attached drive shaft). - There’s no “down down” involved. - The other required changes can be made whenever i like. There’s no timetable. The van is always running anyway. - In addition, i have ROOM for an AWD rear end. I do NOT have room for another van ! - More later. Thank you.

hello, friend. I do NOT denigrate their intelligence. I am disappointed that they did not pay attention to the question. - I am disappointed that no one said, simply, “I don’t know. I haven’t done that.” - I am disappointed that all kinds of OTHER things were addressed (like having to have power for the electric motor ?) - (really ?) - that had nothing to do with the real question (which remains). - Also, i respect the mechanical interest you have by your assembly of tools, etc. - I have NONE of that ! - But, sometime back, i had to have a rear end dropped (by a ‘professional mechanic’) and it certainly did not cost me an arm and a leg, let alone $50,000. - You bring me the $50,000 and I’ll do it for you. - (Of course, i know you are not interested in doing it anyway.) :wink: You know. — I’m just going to assume it can be done rather easily. And go from there. Will report to you later on this subject.

What you are saying is that you will have two independent power systems–the internal combustion engine driving the front wheels and the electric motor driving the rear wheels. If the internal combustion engine will not be powering the front wheels when the electric motor is driving the rear wheels, and the electric motor driving the rear wheels will be off when the internal combustion engine is driving the front wheels, this may work out. However, I’m not certain that there would be a big fuel savings since the internal combustion engine would always be running.

On the other hand, if both systems are to propel the car, then some sort of sophisticated system is needed to apportion the power. I remember the old CJ-2 Jeeps had a problem that in 4 wheel drive, it was hard to keep the front wheels and rear wheels turning at the same speed. It seems to me that this may be a problem for you as well.

If you can, you might study the service manual for a Toyota Prius or a Honde Civic Hybrid to see how this dual system works.

Exactly, RK, I might even bet that nobody in the US has tried to put a rear axle under a fwd Caravan. I bet you can’t (without lots of work), the floor pan’s probably different. Easy to check, find an AWD version and look!

YOU GOT IT _ ! ! !! That is exactly what I’ve been trying to find out .
THANK YOU !. - - - - If it doesn’t fit ALREADY, i KNOW it’s going to be expensive. -

I just believe that the designers of the uniweld body did NOT have to design two different bodies for these installations. - That’s what I’m trying to find out. -

There you go, guys ! - If i knew what the hell i was looking for i would do it ! - (Of course I’d first have to find an AWD drive van, etc.) - But maybe my local garage guy (Dodge) knows of one or has worked on one. - That’s why i was inquiring in this space. - You guys DO this (much more than me). - If the ‘floor pan’ (as you say) is different, then, I’m probably in trouble. It would be too expensive to adapt. - (I would consider the floor pan to be part of the uniweld body construction.) -If that is NOT designed to be used by EITHER the AWD or the NOT AWD, I’m in trouble. If it’s NOT an easy drop and replace, i will not do it. - Simple.

You understanding of my intention is correct. - The ICE will ALWAYS be running (in neutral, at very low RPM)to provide standard power steering, brakes, etc.) - It will be providing no torque to the front wheels. The (in town) torque will be provided by my electric motor and controller (powered, of course, by batteries). -The motor shaft will be attached to the transfer case of the rear end AWD drive (in place of the normal drive shaft from the fwd engine). - Only the electric motor will be mounted beneath the van. Everything else will go on the inside of the van. - When torque is wanted from the ICE fwd (no longer in neutral), the electric motor power will be cut off. The rear wheels will free wheel.- The savings relate to the savings in torque power. In town, that will come from my battery system, not the ICE. - There will be no torque competition between the two systems. Thank you.

You aren’t looking for AWD. You are alternating between FWD and RWD. I think you may want to set it up so that you have regenerative braking so that the motor serves a a generator and puts energy back in the battery.

Your project is something I might dream about doing, but I would never try to carry it out.

Yes. When driving with the ICE in neutral, i will be using regenerative braking. - At this point, i will disconnect the motor when the ICE is not in neutral. - No. I will NOT be using both systems at the same time, so i will NOT be using it in an AWD mode of operation. - I just need the AWD rear end to implement the design. -