GM fullsize AWD Van Info thread

[boardrider247]

Has anyone considered swapping the front drivetrain from an AWD Express into a RWD model? Would everything bolt up? Basically, I have an 8 passenger G1500 that a) is getting cramped from having more kids, b) is going to need an engine at some point (had a misfire since I bought it 60k mi ago, best I can figure is it's developing a flat spot in the cam, plus it's burning a lot of oil these days), and c) the cheap repaint the previous owner did is peeling off. From what I understand, GM never offered a 12 passenger model in AWD. Is it crazy to think I could swap the front end, transmission, and transfer case over to a newer 12pa model? Might have to deal w/ 6 vs 8 lug hubs, but are there any other major hurdles?

As I understand it they are totally different chassis. The AWD models are torsion bar front suspension and the rwd models are coil spring front suspension. That being said I have not been underneath of a 1500 RWD (do they exist?) to confirm that those are coil spring. I do know that the 2500/3500 RWD are for sure coil sprung front.

 

[Scotty D]

Pretty sure that 12 passenger van is not going to be a 1500

 

[camrg77]

As I understand it they are totally different chassis. The AWD models are torsion bar front suspension and the rwd models are coil spring front suspension. That being said I have not been underneath of a 1500 RWD (do they exist?) to confirm that those are coil spring. I do know that the 2500/3500 RWD are for sure coil sprung front.

Interesting, yeah mine is torsion bar, I figured the RWD models would be the same.

 

[camrg77]

Pretty sure that 12 passenger van is not going to be a 1500

Correct. All the 12 passenger vans are 2500/3500 but all the AWD models are 1500. So I was wondering if I could swap the 1500 front drivetrain onto a 25/3500 chassis to make a Frankenstein 12 passenger AWD.

 

[Scotty D]

Correct. All the 12 passenger vans are 2500/3500 but all the AWD models are 1500. So I was wondering if I could swap the 1500 front drivetrain onto a 25/3500 chassis to make a Frankenstein 12 passenger AWD.

with enough effort you can do anything but frankenstien is correct. Even just sorting out which transmission you would use. I dont think the 4l60E would work and I dont think the transfer case plays well with the 4L80

Then there are the rims. 6 hole in front , 8 hole in back?

I you end up doing it, I would sure love to see a write up on it

 

[Seaweed]

We have moved over to a truck camper and ours is listed here in the classifieds. It’s been an awesome van for the past 4 years!

 

[laz 1]

Just bought a 2012 AWD EXPRESS passenger van. Got it cheap because it has issues ... The previous owner drove it for months with no front propeller shaft. Supposedly this toasts the transfer case Gumby goo?? So I have budgeted for a Tcase rebuild or possibly an upgrade??

A local wrecker has a complete Express CLYDESDALE 4X4 CONVERSION with low miles Any idea if the Tcase and front shaft will match up with my stock AWD drivetrain? If so, there might be an opportunity here to upgrade to a true 4x4 two speed system instead of rebuilding the AWD Tcase.

I am transitioning in from years with several AWD ASTRO/ SAFARI vans. Journeys Off Road has a well proven two speed manual shift Tcase swap for these smaller rigs. I nearly built one up a few years ago. Maybe the same system will work with the Express?

 

[laz 1]

One of my previous AWD SAFARI van conversion into a micro motorhome. I have build a few of these, and OVERLANDER from Canada to Mexico several times. Two trips through Baja successfully proved the concept.

 

[vintageracer]

The AWD Express has the light duty 1500 (Half Ton) IRS type of suspension. It's the weak link which limits lift and other aspects. Look to the aftermarket 1/2 ton for upgrades that may work.

The transmission control module also runs through the body control module. Why? Who knows! This makes the transfer case swap to a true selectable transfer case always set a code in the computer. As far as I know nobody has figured a work around for this wiring issue. Yes it will run, drive etc however you will have a code in the computer and light on the dash. The 4L60 is another weak link.

Your CHEAP AWD Express purchase will get mighty expensive mighty quick given some of he mods you have suggested. Add it up BEFORE you leap. You might find that selling the AWD van and purchasing an already converted 4WD drive van from Quigley or another supplier might be a cheaper and better alternative!

 

[drsmonkey]

Just bought a 2012 AWD EXPRESS passenger van. Got it cheap because it has issues ... The previous owner drove it for months with no front propeller shaft. Supposedly this toasts the transfer case Gumby goo?? So I have budgeted for a Tcase rebuild or possibly an upgrade??

A local wrecker has a complete Express CLYDESDALE 4X4 CONVERSION with low miles Any idea if the Tcase and front shaft will match up with my stock AWD drivetrain? If so, there might be an opportunity here to upgrade to a true 4x4 two speed system instead of rebuilding the AWD Tcase.

I am transitioning in from years with several AWD ASTRO/ SAFARI vans. Journeys Off Road has a well proven two speed manual shift Tcase swap for these smaller rigs. I nearly built one up a few years ago. Maybe the same system will work with the Express?

It's not going to be bolt on for sure. I have researched this in the past. It comes down to a few issues that will require some custom solutions.

The donor van likely has either a 4l80e or 6l80e depending on year. We have a 4l60e, different output shaft size.

In theory you could swap the transmission and transfer case onto the 5.3l, but only if the donor has a driver-side front shaft output. You would need to fabricate custom transmission and transfer case mounts and crossmembers, get custom driveshafts made, and use HP tuner to do a segment swap for the TCM. In theory it could be done, maybe.

The front diff then becomes a weak link. Our front diff is from the Astro/S10 and somewhat undersized for the vehicle. The viscous coupler in the AWD transfer case protects the front diff by smoothly applying torque as needed based on slip. A true 4wd transfer case would require very cautious use to keep from blowing up the front diff.

There might be a way to swap the front diff, but it would take a lot of custom work to package it and make everything work with the IFS geometry. I have never measured everything side by side to see if it is possible, but I have regeared my van and replaced the steering rack and can tell you the it is very tight under there. Most of the conversions are using 1-ton truck parts, the frame on the 1500awd is not the same as the 2500/3500 vans so the parts wont swap easily.

 

[thatcabledude]

The AWD Express can be converted to 4wd selectable t-case very easy and cheap with a Np241c t-case and the appropriate front driveshaft. It’s been covered on this forum and there should be a link in this very thread.

 

[laz 1]

Just got off the phone with the Clydesdale shop who did a 4x4 transfer case swap into a 2010 Express 1500 AWD. They do not usually do conversions on the AWD 1500 models. This one had 3" lift blocks on the stock rear leafs and a MANUAL shift Tcase. They used some special Tcase parts from Journeys Off Road, who are very well known for their Astro/ SAFARI AWD to 4x4 conversions.

I have considerable OVERLANDING experience with AWD ASTRO/ SAFARI vans. I have owned over a dozen, custom converted a few into micro motorhomes, and been to Mexico for several Winters ... Including two trips to Baja and tens of thousands of highway miles. The AWD A/S vans are probably the best bang for the buck in an SMALL overland capable van.

NOTE: My personal definition of " OVERLANDING" is bi_annual trips from Canada to Mexico, with some serious off roading in the desert, or bouncing down old abandoned logging roads on Vancouver Island, BC.
YPMMV

But my personal experience with micro motorhome builds, which usually end up well over stock GVW, is that the 4.3 liter is minimal for power. Put on big tires, lower the pressure for sand, and it bogs even in low gear. Solutions include lower gearing (4.10 is supposedly good) or a bigger motor. Journeys is now offering a V8 conversion kit.

I am looking forward to exploring the larger, more powerful Express/V8 platform. More space, more weight capacity = more toys to haul.
PS: I also have previous experience with a Dodge ambulance solid front axle on coils 4x4 conversion, and with a Ford 12 passenger 4x4 conversion using the twin traction beam IFS. Both were BIG and HEAVY. The Express falls into the GOLDILOCKS zone, between too big and too small.

 

[laz 1]

The AWD Express can be converted to 4wd selectable t-case very easy and cheap with a Np241c t-case and the appropriate front driveshaft. It’s been covered on this forum and there should be a link in this very thread.

 

[laz 1]

In discussing this conversion with MIKE, from Journeys Off Road, he mentioned that the front driveshaft from the AWD is a bolt in. However the New manual Tcase requires shortening the rest drive shaft 1".

 

[laz 1]

The AWD Express has the light duty 1500 (Half Ton) IRS type of suspension. It's the weak link which limits lift and other aspects. Look to the aftermarket 1/2 ton for upgrades that may work.

The transmission control module also runs through the body control module. Why? Who knows! This makes the transfer case swap to a true selectable transfer case always set a code in the computer. As far as I know nobody has figured a work around for this wiring issue. Yes it will run, drive etc however you will have a code in the computer and light on the dash. The 4L60 is another weak link.

Your CHEAP AWD Express purchase will get mighty expensive mighty quick given some of he mods you have suggested. Add it up BEFORE you leap. You might find that selling the AWD van and purchasing an already converted 4WD drive van from Quigley or another supplier might be a cheaper and better alternative!