New Tires for Chevy Express 1500, to Lift or Not?

[quagmire1985]

My 2008 Chevy Express AWD will be getting new tires this summer and I'm looking for some opinions. This van is a ski/bike/camping vehicle that sees a lot of snow in the winter and mostly dirt forest service roads in the summer. I'm in Utah, so a bit of mountain roads and a bit of desert. Nothing too crazy. I tow a 3,500lb trailer. This van has been very reliable and I want to keep it that way.

I'm probably going to go up one size to a 265 70 R17, from 245 70 R17, in something like a BFG AT. I'd consider 285 but my gearing seems pretty tall to begin with and I don't want to put too much more stress on the front end which has 120k miles on it.

Better ground clearance and honestly, looks, are part of the decision to go bigger. The transmission subframe is super low on these vans.

2-3" lift and 265 or 285 tires seems to be Standard Operating Procedure for this type of van.

I'm considering doing a torsion bar lift, similar to this kit: https://www.journeysoffroad.com/expresssavanna-lift-kits.html . I'll probably just get the keys somewhere cheaper since I'd get longer shocks to avoid the extenders. I have Gabriel Hi Jackers adjustable air shocks in the rear, and it sits pretty tall, so I might keep that as is. Blocks seem easy to add if it needs to be leveled. I tow a bit and the adjustable air really helps, while keeping it soft when unattached.

I have a few questions regarding the lift.

1. Can I fit a 265 tire on the stock rim with no lift? Tire size calculators tell me they are 1.1" taller and 0.8" wider so they seem like they would fit without any trouble.

2. If I lift my van 2-3" will is screw up the front suspension and drivetrain on the front end? The CV axles and steering are stock, so if I make the CV angle greater on an older system, am I asking for trouble? Do any other drivetrain or steering angle changes come into play with a lift this small?

3. The van has 120k miles with a lot of winter driving. I have air tools and a pneumatic hammer and decent auto experience. How stuck are my torsion bars going to be once I let the tension off? I feel comfortable with the process, but I'm doing this on a small driveway and don't want it stuck on jack stands too long.. There is a bit of rust on the underside, but nothing rotting.

4. Are there any other downsides to a torsion bar lift or bigger tires? I'm ok with a stiffer ride, this thing rides like a cushy sofa now! Does the increased height make it noticeably top heavier? I already can't park anywhere indoors so size isn't an issue.

My options, listed by difficulty are 245's no lift, 265 no lift, 265 with 2-3" torsion bar lift.

Thanks in advance.

 

[Choff]

Welcome, Looks like a nice van , on tires, I have gone to 17 inch rims (2005 GMC Denali rims) with 265 and just put on Nexen Roadian AT Pro RA8 All-Terrain Tire , like them so far, great in snow this winter. No lift other than air bags in back., I can fit in our 7' garage door opening with about 1 inch clearance. Remember the spare tire also. get the same rim and same size tire!!! it fits under the back no problem.
And yes we use it every winter, drive the wheels off if it. Camping and lots of road time down south to the Carolinas.
Just turned 206,000 miles on our 2005 GMC AWD Savana full conversion, got it with 43,000 miles.
I VOTE NO LIFT, also my wife is shorter than me and i have to goose her to get in the van.

 

[vintageracer]

Here are ALL the answers to ALL your questions.

HOURS of reading and learning (35 pages) about the do's and don't's on GM Express/Savana full size AWD vans.

https://www.expeditionportal.com/fo...d-van-info-thread.137390/page-34#post-2628688

 

[boardrider247]

Here are ALL the answers to ALL your questions.

HOURS of reading and learning (35 pages) about the do's and don't's on GM Express/Savana full size AWD vans.

https://www.expeditionportal.com/fo...d-van-info-thread.137390/page-34#post-2628688

This.

The quick answers to some of your questions

1. I don't believe so, at least not without some rubbing at full lock.
2. No drivetrain issues yet with my van. Probably close to 80k on it since the lift
3. Soak them early and often with a quality penetrant. Kano Kroil, PB blaster or ATF/Acetone mix. Mine dropped right out. Others have struggled. Kind of a crap shoot probably how hard they are to get out
4. Gas mileage. I dropped about 3 MPG with the lift and tires. Otherwise I didn't notice any significant changes in driveability.

 

[Scotty D]

One thing that rarely gets mentioned is that if you put bigger tires on , you are making the gearing taller.
First gear on this transmission is already too tall for my taste and shows up when you have to negotiate some rough terrain very slowly and need to go up a very steep hill or get over a rock.
If you dont get offroad much its not a big deal but in baja it can be a problem.

 

[quagmire1985]

Thanks for the replies.

I have definitely read the GM Fullsize thread through since owning my Van. It's an awesome resource.

I should have been more specific on my question. I'm more curious on the effects of changing the angles on the CV axles and other front suspension items after 11 years and 120,000 miles in the stock position. I imagine the torsion bar lift "extends" the suspension more, making it ride higher and rest on different areas of the bushings, basically setting a different "resting" or "zeroed out" point.

Does the torsion bar lift accelerate wear on any components? Are my fears unfounded?

 

[Len.Barron]

Yes it will accelerate wear. The more you lift the more static angle you run, during any turning the (now higher) angles are compounded, but, it's just the price of doing this type of mod.
The truck guys have access to a lot larger lift product line that include differential drops that return the angle back to stock position, modifying(one from a truck) or building your own diff drop is an option if you can't live with the lower front shaft life.

 

[bdog1]

I believe the CV angle is neg. stock, so a moderate lift might improve the operating angle.

I think moderate is key here, an inch plus or minus.


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[XJ-Maki]

I just bought a 2005 Savana AWD and have the same questions as Quagmire. Trying to decide between 245 and 265. In my case I don't want to do any lift beyond adjusting the stock keys (got me a surprising 2.25" of lift going from 1/2" of thread showing to bottomed out) and adding load assist shocks in the rear (gained .75" and the rear is now exactly 1" higher than the front). I've been battling pinion angles and caster and driveline vibes on lifted Jeeps for 15 years and don't want to do it on my van. It rides like a Town Car right now compared to my XJ.

I want to stick with the very nice stock aluminum 16" rims and am loyal to the Duratracs. It looks like the 265/75R16 Duratrac is actually $10 cheaper than the 245/75R16 too. I just picked up an alloy Suburban rim to replace my rusty steel spare and it has a 265 on it so I think I'll test fit that and see how it looks lock to lock etc. I think it will fit easily.

Also is it generally recommended to go with a load range E for a fully kitted van? Always tried to avoid them with Jeeps but it seems that what the Class B forums recommend so they can run crazy high PSI.

 

[dleeallen]

I have 265 BFG a/t on my stock wheels at stock ride height. If it rubs it's very occasional and hasn't left a mark to prove it.


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[45Kevin]

On my van the stock suspension had the front axles slightly higher at the wheel than the diff.
New Rough Country keys gave about 2.5" of lift and the axle end of the axle is now about the same difference lower than the diff. So really, no change in axle angle, just opposite.

I run my 235/85/16 tires with no rubbing. Load range E BTW.

I put the 2700# suburban springs in the rear and got a couple of inches of lift there, along with more load capacity.