GM fullsize AWD Van Info thread

[boardrider247]

Since transmissions came up in the last conversation I have to ask. I only have D321. I haven't seen an overdrive off switch or anything. How are folks preventing the insessant overdrive hunting that automatic transmissions sometimes do in the mountains?
Does the tow/haul mode help (if this tranny even does that hunting thing)?
-G

Honestly that is my largest gripe with these vans. So far I have not found the tow mode to help significantly.
Mostly on tight steep runs i.e. Durango to silverton I shift down a gear and just take it a bit slower. Or really keep your foot in it and hold on:smiley_drive:

 

[fire_strom]

Dang. I'll go with option 2 for Durango to Sliverton. For Sliverton to Ouray, option 1 with eyes closed.
Thanks!
-G

 

[Accrete]

Thanks 86cj. That all still makes me think the 3.73 would be better long term...

Back when there was a similar discussion I remember matching the appropriate door-jam plate info and remember it having the 3.42/LSrear option. 86cj is way ahead of me in knowledge/info on the particulars as I have no RPM gauge on our rig. In the hills it doesn't spend much time in OD and seems to do fine for us. We are glad to no longer be towing, but that is mainly because we want more freedom to explore without worrying about having figure out what to do if the trail becomes unpassable and we have to turn around on a one lane forestry road ; )

Thom

 

[TeleSteve]

Back when there was a similar discussion I remember matching the appropriate door-jam plate info and remember it having the 3.42/LSrear option. 86cj is way ahead of me in knowledge/info on the particulars as I have no RPM gauge on our rig. In the hills it doesn't spend much time in OD and seems to do fine for us. We are glad to no longer be towing, but that is mainly because we want more freedom to explore without worrying about having figure out what to do if the trail becomes unpassable and we have to turn around on a one lane forestry road ; )

Thom

You should be able to select and view a tachometer in your Driver Information Center in your 2010, it rounds to the nearest 100, but is better than nothing.

 

[Accrete]

You should be able to select and view a tachometer in your Driver Information Center in your 2010...

Ah U R right... being an old school 60's & 70's muscle car guy recalling the dash mounted tac... I really didn't think of selecting the RPM-ish digital version. Maybe next trip as an experiment.
: ) Thom

 

[boardrider247]

Added a few more build threads to post#6

 

[North]

Is the stock stereo in the Express a standard Double DIN unit or GM-specific size? I want to replace my stock unit so I can hook up a backup cam, but the options Crutchfield is spitting out seem really limited. Anybody have the same experience? Any recommendations on a Double DIN stereo that fits well and has good resolution for the backup cam?

 

[fire_strom]

Standard double DIN, which is only a height/width rating. It's the depth on the GM van that's the issue. The tolerances are tight. I didn't like any of the units so I called about a Pioneer unit and they admitted that they err on the safe side so they don't get the ****** calls from people that get bound up by challenges. I ended up ordering a Pioneer 4800BS something or other. It should be here tomorrow so I'll report back on the fit ASAP. I got a set of Polk speakers for the rear roof and front doors too. They're my only stock location. I also have a TaddiBrothers wireless 3rd brake light backup camera on order so I'll pipe in on that too. I just need to pick out a little powered sub woofer to round out my A/V. Even old man music needs the low end!
-G

 

[Pest]

I just need to pick out a little powered sub woofer to round out my A/V. Even old man music needs the low end!
-G

We ended up getting a little Kenwood KSC-SW11 Compact Powered Enclosed Subwoofer (just using the stock head unit though). It's very small, fits nicely under/behind the passenger seat.

If you're looking to shake the cars next to you or blow your ear drums, this won't do it. But it sounds really good. It adds just the right amount of kick while being tiny and easy to install.

https://www.amazon.com/Kenwood-KSC-SW11-Compact-Enclosed-Subwoofer/dp/B00BO8O9XQ

 

[dleeallen]

Has anyone added trailer wiring (lights and brake controller) to an AWD GM van that didn't have the trailer prep? I've got a plug and play light wiring but not sure how to best get the plug run to underneath the van. The instructions just show it routed out the rear door and down behind the bumper which seems kind of lame. Since I also need to wire up a electric brake controller I'll want those wires running out to the hitch plug as well. Any suggestions from experience?

 

[710m]

I've been curious about them too. The Quigley long wheel base could be a nice rig but I wonder how hard those 150k miles were... I notice that one has a brake controller so it must have spent some time towing. The question is how much time and how much weight...

I bought one of these (a 2011 with 46k on the clock) this spring. There were two available in Colorado at the time and one was in much rougher shape than the other. Mine isn't too bad although I had a few electrical issues with it because some critters had gotten in there. Otherwise it is in decent shape. I have a build thread on my conversion with a few more details.

 

[TeleSteve]

Has anyone added trailer wiring (lights and brake controller) to an AWD GM van that didn't have the trailer prep? I've got a plug and play light wiring but not sure how to best get the plug run to underneath the van. The instructions just show it routed out the rear door and down behind the bumper which seems kind of lame. Since I also need to wire up a electric brake controller I'll want those wires running out to the hitch plug as well. Any suggestions from experience?

I ran mine out through the grommet for the rear driver side door. The flex boot in this picture was added later to run speaker wiring to the door. If you have rear speakers the boot will be there if not, there is a plastic plug in the body.

I ran the brake and battery power wires from under the dash down to the floor and then up the A pillar and to the back of the van next to the factory wire harness.


Sent from my iPad using Tapatalk

 

[drsmonkey]

Has anyone added trailer wiring (lights and brake controller) to an AWD GM van that didn't have the trailer prep? I've got a plug and play light wiring but not sure how to best get the plug run to underneath the van. The instructions just show it routed out the rear door and down behind the bumper which seems kind of lame. Since I also need to wire up a electric brake controller I'll want those wires running out to the hitch plug as well. Any suggestions from experience?

I ran the 12v+ for the trailer battery and power for the brake controller off of the post that feeds the fuse box under the drivers seat and installed the breakers inside the box. I used the OEM harness routing under the drivers seat to get to the dash (for the controller) then up the A pillar. I pulled the OEM wire channel along the roof to get to the rear drivers side corner.

If you crawl under the van and look in the bottom rear corners of the body looking to the rear you will find a black plastic cover that accesses a small box that is at the bottom of the rear pillar. I drilled a hole through the top of that box from below (just plastic) up into the rear pillar and another one in the cover. Fished the wires down through there and out a grommet in the box cover. I left a small service loop inside the box for future use just in case.

Nice and clean with no wires in or around the doors.

 

[fire_strom]

I also used that bottom of rear pillar area but didn't drill anything except the plastic cap on the outside box. There was enough room to fish the wires through a bit of the foam seal down there. I had less wires though, I brought my power through the frame rail. Worked out really clean.
I have no speakers on the rear doors but I do have the defroster so there were rubber boots in my way too.

@Pest that's just the sort of sub I'm looking at. Thanks for the tip I'll check it out.

-G

 

[dleeallen]

Thanks for the ideas on the trailer wiring everyone! My van is at the shop getting a few 'new owner' things done that I didn't want to do. Trans service, alignment, etc... I'll crawl around it when I get it back and see if I can't figure out the wire routing.