Hi guys,


I have a shorty Dodge Ram Van 1500 (1999) that I have added a camper topper too, 240w solar (Going to be 1KW shortly), 4x4 foot sun deck, 14 gallons fresh water w/ sink, tables, and toilet w/ septic. Having it weighed, with full loadout, food, extra water, I am exactly at the GVWR. I have Hellwig helper springs I have yet to install, but I want to upgrade the rear axle as I want to add a small motorcycle to the back.

I have been told it's a straight swap, and I have been told the driveshaft will have to be shortened. I looked it up and my axle is one of the same types they put under Jeeps. The people in town want $300 to shorten the drive shaft, so I want to avoid that, if possible. Other people have said that I need to cut the hangars off of the frame of the donor 3/4 ton vehicle and weld them onto my van... Can I use the stock 1/2 ton springs and helper springs and just bolt the 3/4 ton axle up underneath?

 

I put the 2500 springs on my rear axle I have still have the 8.25. Everything mounted fine, so I would think the reverse would be true. I think you will have to shorten the driveshaft too (not 100% on that). I had to when I put in the 4speed in over the 3 speed - but that is pretty obvious.
What I am thinking about is the 9.5 axle has 6 lugs. So you will have different pattern front and rear with potentially, different tire and wheel sizes. Is there a 5 lug 3/4 ton rear?
I would think to do it right - and yes I have had the same thoughts you have - I would find both the front and rear setups from a donor van. You would need basically everything from the front...but it really wouldn't be that hard of a job.

 

Wow that is a good question, maybe if I go 3\4 or 1 ton rear end I will have to go rear wheel adapters to use the same rims unless I put the heavy duty front end in as well which I don't know if I'll do...

 

No - I wouldn't do wheel adapters.
There are 9.25 five lug out there, I think. But it believe it would be out of a car from the 70s. I am unsure if it would bolt up to a late model van, but I am sure it could be done.
There are several spline amounts too - 29, 31, 33, and 35. Some think that the more splines the more strength, and that is basically true. The Corporate 8.25 is a good rear though and it is good up to 4500-5000lbs. The front axle, with the five lug is "only" 3500.
The weakness is really in the front and not the rear. I think the only way to do it right is to replace both front and rear with a late model van 6 lug set up.
I may do this someday...heck I swapped the 3.9 for the 5.8 LOL

 

I have a 99 ram van... and have some experience swapping out axles on these and trucks, other vehicles... I'm assuming that your axle is a dodge 9.25 (fairly strong, somewhat underrated axle...). I'm not sure what kind of vehicle or which axle you are talking about putting under it instead? note that dodge ram truck axles, springs, etc... are NOT a bolt on situation at all. Nothing is to my knowledge. The Ram van axles are about 4 inches narrower the spring perches are in different places and at a different angle relative to the differential... Note that if it's like mine, the speed sensor is in the differential as well so that's got to be consistent....

I would suspect that the axle itself isn't the limiting factor in setting the gvrw, it's most likely the springs, brakes, etc...

If you're dead set on changing the axles (rather than updating springs, brakes, etc...), why not find a ram 3500 ram of similar year and put that in it and swap the front end stuff and wheels as well... not simple, but I'm pretty sure you'll have the same issue with rear ends... I would want a Dana 60 or 70 from a similar year van in it if it were me... That said, I have a dana 60 from a 98 ram truck under mine (cut spring perches off and welded new ones on)... but then you're still going to have the deal with the expense of getting lug pattern / wheel offsets to match for front and rear... I can't think of any simple / easy way to do what you're wanting to...

 

You are correct if you want to put anything other than a van axle under it. That would be totally fabrication.
The 98-03 shorties - what I have - only came with the the 3.9 and the 8.25 in the rear as far as I know. the standard wheelbase 2500.3500s did have a 9.25 but it is six lug and not five - that is what he should have.
If you swapped out the 98-03 2500.3500 9,25 rear, as far as I know it all should bolt up but a custom driveshaft would be needed.. But then you are have six lug axle with a five lug axle in the front.
To do the front so you can upgrade to 6 lug, you would need lower control arms with ball joint, the spindle, and the hubs/rotors and it would be a direct swap.

 

maybe 8 lug axle in the rear? ;-) I'm sure you know, assuming just a type / brain fart...

I'm thinking the best option to upgrade the axle from what you're (OP) asking, is to find an 02 or 03 3500 van with a dana 60 or 70 in the rear (you also get much better disc brakes with that, cant remember what year the change was ;-) ), and swap out the front end parts to get you the heavier 8 lug spindles, etc... would be worthwhile to see if the heavy duty front brake calipers for the trucks would work there. I did those in the front of my *8500+ frankenvan along with heavy duty truck rear drums and oversized (chevrolet) pistons on the rear and it stops REALLY well for such a pig... (I put a 2500 4x4 truck Dana 60 with 4.10 gears under mine. had to cut spring perches off, weld new ones on at a slightly different pinion angle so the driveline geometry would be right... not trivial, but not ridiculously hard. I used the original van springs, but added several more leaves to give them more arch and a higher spring rate). Hope this is helpful / puts things in perspective...

 

Yea - LOL - I had a BF...
I think you are right on... I would really like my van to stop better too...any pics?

 

I am considering pulling a transmission for my van as it slips badly in 1st gear and needs 2 extra quarts above fill line to move and shift reliably. (I plan to rebuild it, other than that this van is very reliable!) Let me ask you something, are you getting better MPG with the 5.8? My 3.9 can't get out of it's own way... It does well once at highway speeds but getting there takes a while. Did swapping to the 5.8 help with fuel mileage at all? Like, it doesn't have to work as hard? I have a O2 sensor code being thrown, but I get about 12-14 MPG highway, but that was before I added all the camper stuff so it may be less now. May do a more stout transmission and engine swap, both. Upgrade to 5.8 and whatever trans I can with that (4 speed? Mine is a 3 speed)

 

What year is your Van?