Accrete
Explorer
Greetings, I searched through my posts over at my build thread and found this from prior research : )
Thom
GM fullsize AWD Van Info thread
- Thread starter boardrider247
- Start date
My 2010 cargo has the 3.73 with G80 locker. With my 33.2" tires sometimes I wish I had lower gears when driving in the hills when loaded up, but it isn't bad. For flat terrain and rolling hills they work well. Before the larger tires and interior build, I didn't feel they were too low geared and fuel mileage was still good.
It depends what you plan to do with your van. Stock or smaller size tires, light loads, and more flat driving the 3.42 would probably provide better fuel mileage and adequate power. If you want larger tires, are loaded most of the time, or frequently drive in steep mountain terrain the 3.73s may be better. Also the 3.73s would be better for towing.
You make great points. I'm still working through which options are critical to what I buy and I think the 3.73s would be smarter. I expect to do some towing and live in VT where it's not real flat... I'll also expect to put larger tires on at some point. My interior build will be minimal though. But if the 3.73s aren't bad for normal passenger van driving they are probably a smarter place to start. I think the G80 is also smart. So much cheaper/easier to just have it from the factory. Thanks for the response.
Accrete
Explorer
Our e rated 265/70/r17's are just a smiddgen over ~32" tall up from the stock 245's at ~30".
Running the van just under GWVR loaded for adventure we were still able to pass going uphill (Oregon coast range and Cascades) pulling our (now sold) 15ft fiberglass TT weighing 2400lbs at scales. Didn't really notice it was back there.
Thom
Running the van just under GWVR loaded for adventure we were still able to pass going uphill (Oregon coast range and Cascades) pulling our (now sold) 15ft fiberglass TT weighing 2400lbs at scales. Didn't really notice it was back there.
Thom
Thom - Just to be sure - your van has the 3.42 gears? And you have no complaints about power with taller tires and interior build? Even while towing a moderate load on hills? That's great news. Finding a nice van is hard enough without having to get the 'right' gears too!
Herbie
Rendezvous Conspirator
The other way to look at it is to question whether you'll keep the stock gears in the long run anyhow. My Astro has 3.42s, but with 30" tires, I'll be needing a gear swap soon. 3.73s would help, but the reality is that I'll be running 4.11s. Granted, that's behind an Astro with the 4.3L V6, but even on the big vans, 3.73 could be marginally short enough if you end up with really tall tires and you might be changing anyhow...
The G80 is nice to have, and I suppose you could hold out for one, but again - if you feel like you'll be doing a gear change, then it seems a shame to pass up on otherwise good vans when you can fix the ratio and LS/Locker issue aftermarket.
yep, 3.73's are 'just' adequate for the mountains (8000-12000 ft hwys). With 32" tires I would love 4.10's... or, a low speed transfer case. (Not a rockcrawler, but occasional steep, loose hills), but G80 and 3.73's work on forest roads.... but, your forest roads may vary, mine are 'don't attempt, park & hike' - jeep kinda stuff around here.
86cj
Explorer
My van has 3:73 with 265's and runs 2100rpm at 70mph in OD and about 2800rpm in drive, that number drops to 2600rpm with 3:42 gears. If you are loaded for camping hopefully mountains or at least hills are in part of the journey, so can your van stay in O/D all the time? Even if it can you might not want to due to lugging issues and prefer to keep the trans in drive for certain terrain (to help the brakes), it does not kill MPG's as much as you might think.
So actually the 3:42 gear is less likely to stay in O/D but has a better sweet spot for mpg's when forced to run in drive and "not be in the way of normal traffic". My 5.3 still does great on fuel when running in drive or 1:1, 2800rpm seems worse to me than to the motor it has tons of power at that RPM. I too feel a 4:10 would be nice with the bigger tires and weight but if you still can't pull 2300rpm in O/D now your running 3000rpm at 70mph.
BTW it does take a pretty steep grade to make my van downshift from O/D so the 3:73 does work very well with the 265's, just don't feel to bad about only finding a 3:42 geared AWD Van the 4L60 trans also has a decent first gear ratio to help a little. Who is going to be the first to try some 4:10's?...........
So actually the 3:42 gear is less likely to stay in O/D but has a better sweet spot for mpg's when forced to run in drive and "not be in the way of normal traffic". My 5.3 still does great on fuel when running in drive or 1:1, 2800rpm seems worse to me than to the motor it has tons of power at that RPM. I too feel a 4:10 would be nice with the bigger tires and weight but if you still can't pull 2300rpm in O/D now your running 3000rpm at 70mph.
BTW it does take a pretty steep grade to make my van downshift from O/D so the 3:73 does work very well with the 265's, just don't feel to bad about only finding a 3:42 geared AWD Van the 4L60 trans also has a decent first gear ratio to help a little. Who is going to be the first to try some 4:10's?...........
Thanks 86cj. That all still makes me think the 3.73 would be better long term. I'm also a bit curious about 50mph cruising RPM. Sounds like it would likely not be in O/D for that speed?
I did a cross country trip in a V10 Sportsmobile that wasn't geared well and it sucked. It was perfect for about 80mph but not great otherwise. So I'm extra sensitive to buying the right one. Especially because I know I won't re-gear it later. Sort of like the locker - I'm better to buy one factory rather than think I'll add one. I just know how it will go and coming up with the lump sum to do that sort of stuff is always low on the list compared to other mods!
I did a cross country trip in a V10 Sportsmobile that wasn't geared well and it sucked. It was perfect for about 80mph but not great otherwise. So I'm extra sensitive to buying the right one. Especially because I know I won't re-gear it later. Sort of like the locker - I'm better to buy one factory rather than think I'll add one. I just know how it will go and coming up with the lump sum to do that sort of stuff is always low on the list compared to other mods!
fire_strom
Adventurer
Thanks for that conversation. I'm in Colorado and will be towing a 3000# travel trailer as frequently as possible. I found a 2013 w/ 77.2k on the clock. I happen to be in MI and found it here. I bought it today and will drive it home. Metallic blue LS with 3.73 gears!
GAME ON!!!
Thanks again,
-G
GAME ON!!!
Thanks again,
-G
86cj
Explorer
The RPM at 50mph in drive is 2100rpm with my 3:73, same as 70mph in O/D, so take 200rpm off for a 3:42 gear ratio. It has to be pretty flat to pull O/D at 50 mph loaded, but the MPG readout will be 20 for some AWD Vans. If you could run 50mph all day you would be bragging about your campers mpg's to all your friends, I run that speed when sightseeing someplace cool. The 5.3 will pull all but the crazy steep stuff at 2000rpm or above in drive, it likes mid 2000rpms best for power.
fire_strom
Adventurer
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
Does the tow/haul mode help (if this tranny even does that hunting thing)?
-G