GM fullsize AWD Van Info thread

[Inspired Adventurist]

FUSE HELP!!!

Does anyone have an idea on what fuse(s) control the cigarette lighters in the cab of an 2003?

I've consulted online guides and popped the fuse boxes open (under hood and under drivers seat) to find the fuses intact in both the main and aux cigarette lighter slots. I replaced them anyway to no avail. I don't want to pull all the fuses randomly, as that seems like a way to cause more problems. I'd really like to get back to using them for charging my phone, etc on long drives. They burnt out when I used my compressor to air-up my tires. I've wired that directly to my house batteries fuse block now.

Could it be something other than the fuses?

 

[Grinder74]

Anyone swap in the 14 bolt semi floater in the AWD van? Mechanic said r&p are shot, seems like a good time to upgrade. I believe my van has 3:73 gears.

Sent from my SM-G990U using Tapatalk

 

[drsmonkey]

No surprise the leaf shop wants to build me a custom set of springs for 2k. I think i'll go with the suburban springs for now.

Anyone use the rough country control arms? Im wondering if these would work. https://www.roughcountry.com/gm-for...tml?find=2006-chevy-silverado-1500-4wd-736544

I don't think those UCA's will work on our vans, you need the previous generation (99-06) Silverado UCA's.

I good way to check this is to use either a GM parts catalog or Rockauto to compare part numbers between your van and the possible "donor" vehicle

 

[andrew4566]

Finally got my suspension mods/tires sorted, thanks to all the great contributions here on EP: I started out with the MaxxCam2 keys (3inch), 3/4 Suburban leaf springs, Bilstien shocks; one block down the road It was apparent that I need to try the upper control arms as the ride was terrible.
Cognito control arms now installed, the van rides better than ever before. The firm leaf springs, tightened torsion bar, firm shocks have given the van a sport car feel in the tight twisty turns; I can punch it and pass on a turn with no wallow/sway. The Cognito upper control arms allow for movement throughout the range needed for rough road; the stock control arms were bottoming out in the dips/potholes. I highly recommend the Cognito upper control arms for a supple/flexible response for rough road driving. I'm still going to modify the bumpstops front/rear with spacers for the new height. The stock ones have a large gap; I'd like to have the bumpstops be an additional component to improve stabilty. I went with a taller than stock, but skinny set of tires for good snow tracking and no rubbing; Toyo Open Country A/T lll's are handling ok, with acceptable road noise. I'm still fiddling with tire pressures to get the best handling; 45 psi still seem a bit high for my weight and driving style; going to go down to 35 psi.

Toyo OPEN COUNTRY A/T III LT235/85R16
MaxxCam2 keys (B3 Setting) front
General Leaf Springs 3/4 Suburban rear
Bilstein 24-186643 on the front
Bilstein 24-185615 on the rear
Cognito 110-90289


View attachment 697775

Any idea what your rake is now? I carry a load in mine almost always so stock it is about 1" low in the rear.

 

[Willsfree]

Any idea what your rake is now? I carry a load in mine almost always so stock it is about 1" low in the rear.

Rake is less than one inch in the rear. Suburban springs lift 3+ inches over stock. Max keys have given me almost 3 inches in front. Cognito control arms allow for full range of motion. One inch increase from new tire size all around.

 

[jonnypage]

Has anyone run some Icon shocks on their awd? Having a hard time deciding which shocks to get!

 

[2006Express]

Here is my 2006 with 2 inch front and 3 inch rear set up.

 

[andrew4566]

Express van AWD is 2005.
If you read my post, the Cognito control arms allowed the suspension full range for the tires to drop into holes and rise over bumps. Whereas the key lift only was unmanageable; every bump/pot hole/ road imperfection was jarring the suspension as it had topped out, tire couldn't drop into any depressions. The ride and handling was dangerous. As far as accelerated wear on parts, holding up well for 20k miles now. Van has good brakes, tires, suspension for blasting up to the Sierra during big snow storms. I highly recommend the control arm mod.

3/73 or 3.42 gearing? If 3.42 did you loose much with the taller tires?

 

[Willsfree]

AXLE,REAR,3.42 RATIO on my 2005 AWD Express.
The taller tires have affected torque/power up steep grades and deceleration on the downhills; noticed on roads like highway 108, Sonora Pass etc.
It would be an expensive regear for both rear and front differentials.
I've been driving it as is for the meantime.
If I add a Truetrac to the rear I would consider a regear.

 

[Scotty D]

AXLE,REAR,3.42 RATIO on my 2005 AWD Express.
The taller tires have affected torque/power up steep grades and deceleration on the downhills; noticed on roads like highway 108, Sonora Pass etc.
It would be an expensive regear for both rear and front differentials.
I've been driving it as is for the meantime.
If I add a Truetrac to the rear I would reconsider a regear.

This is why I never went with taller tires. My vans gearing is too tall as it is.
In deep sand reverse gear is so tall I have to make sure I dont have to use it.

 

[TheEL]

Wanted to see what the general consensus was about new tires for our vans. From what I can tell its predominately RWD until there is slippage in the rear then transferring more power to the front. Is it recommended to change all 4 tires at the same time still since its AWD?

Asking b/c I blew a sidewall down in baja last week. My tires (toyo open country at2s) have about 30k on them. They have some more life left and dont want to swap all 4 if I dont have to. I made it back using my brand new spare and have 3 older tires on there. Would it be ok to put 2 new tires in the rear and keep the older ones up front?

Feel free to rip this apart. As I've stated before Im pretty mechanically dumb. This place has helped me learn a lot!

 

[marret]

Wanted to see what the general consensus was about new tires for our vans. From what I can tell its predominately RWD until there is slippage in the rear then transferring more power to the front. Is it recommended to change all 4 tires at the same time still since its AWD?

Asking b/c I blew a sidewall down in baja last week. My tires (toyo open country at2s) have about 30k on them. They have some more life left and dont want to swap all 4 if I dont have to. I made it back using my brand new spare and have 3 older tires on there. Would it be ok to put 2 new tires in the rear and keep the older ones up front?

Feel free to rip this apart. As I've stated before Im pretty mechanically dumb. This place has helped me learn a lot!

If you have AWD, traction control, limited slip, etc. I believe the recommendation is to replace all tires. For limited slip, at least both tires on that axle. I am not real familiar with the AWD system on your van.

For my auto lock G80 axle, in your situation, I would replace both tires and run the old tires on the front. 30k miles is significant miles.

 

[TheEL]

If you have AWD, traction control, limited slip, etc. I believe the recommendation is to replace all tires. For limited slip, at least both tires on that axle. I am not real familiar with the AWD system on your van.

For my auto lock G80 axle, in your situation, I would replace both tires and run the old tires on the front. 30k miles is significant miles.

I should have noted mine is a 2007 so no stabilitrak

 

[marret]

I should have noted mine is a 2007 so no stabilitrak

Maybe someone with more knowledge will come along.

Found this:
The Chevrolet Express AWD van using a Borg-Warner 4473 viscous coupled transfer case with the front output on the driver side. This transfer case relies on differences in drive shaft speed to engage the front drive shaft. Copied from member @zuren post for a 2005. I believe they are all the same.

I found something here that said more than 1/4" difference could cause damage:
https://www.jimjenningstransmissions.com/faq/4-wheel-all-wheel-drive/varying-tire-sizes/

How much wear/difference in size is there with 30k miles?

 

[TheEL]

Maybe someone with more knowledge will come along.

Found this:
The Chevrolet Express AWD van using a Borg-Warner 4473 viscous coupled transfer case with the front output on the driver side. This transfer case relies on differences in drive shaft speed to engage the front drive shaft. Copied from member @zuren post for a 2005. I believe they are all the same.

I found something here that said more than 1/4" difference could cause damage:
https://www.jimjenningstransmissions.com/faq/4-wheel-all-wheel-drive/varying-tire-sizes/

How much wear/difference in size is there with 30k miles?

Woof. Pretty significant difference. Hopefully the ~500 mile trip home didnt do too much damage. 😬

Guess ill go ahead and replace all 4.