Chevrolet/GMC Van suspension lift/rear locker questions

[ADVANTR]

Need some info from the Express/Savana gurus on the forum here:

My van is a 2005 GMC Savana, 2WD, 3/4 ton with 6.0 liter. Has 8 lug axles. Coil spring front end. No torsion bars here! Appears to have some type of factory lift over the 1500's I see running around. The front end is 2.25 inches lower than the rear as measured from the ground to the fender.

I am looking to make my van just a bit more formidable down dirt roads and off road excursions. I know darn well this beast has significant limitations when the pavement ends. Not trying to make it a rock crawler or anything of that sort, but also don't want to get hung up right away. I am planning a few more mods with this in mind:

- 2 inch lift for the front --> I really like the Boulder Off Road 4 inch kit but I think this is overkill for now. I simply don't need this kind of ground clearance though I think this is a great kit with new spindles and upper A-arms as well. I am not going to be adding oversize tires, so just a few more inches of ground clearance would be all I am looking for.

Does anyone know if the 2 inch spacer kit from a 1999-2006 Silverado 2WD will work on our vans?? I've got conflicting information on this from a few sources. Seems like it should. Daystar, Rough Country sell inexpensive spacer lifts (100-150 bucks). Or is the Boulder Off Road spacer kit worth the 300 bucks as it is specifically designed for our set-up? Do I need shock extenders or longer length shocks if I raise the front 2 inches?? I would want to swap out shocks since I am already there and would seem like a good time to do it.

Are there any drawbacks to adding this type of lift?? I know I will need an alignment, but anything else? Will this affect ball joints, handling or wear on other front end components??

- I am looking at adding a locker in the future. Most likely an Eaton E-locker or an ARB --> still compiling some info. Where is the best place to look to find out what kind of rear axle this sucker has?

- Basic recovery gear. Considering a winch in the future, but for now just some straps, adding a recovery point to the front and likely a Hi-Lift.

Rock on, love this forum. I have learned so much and have gained motivation from all the builds and adventures!

 

[ADVANTR]

Hey guys,

Sorry to be such a slacker. After I posted, I realized I wasn't being all that helpful in requesting that rear axle advice. So, I dug out some of the snow from under the van, an shot this little picture.

I think I have a Dana 60S. Is that a good rear axle?? I remember the previous owner of this van stating something about the rear end being the "optional" one, and it was a few bucks more on the window sticker. Looks like there is a L/S in there. Sure wasn't all that apparent the two times I have had this bird stuck in mud and snow. What type of limited slip would this baby likely have??

Thanks in advance.

-

Xavier

 

[barefoot boy]

Post a picture of the center pumpkin; it will be easier to tell what you have that way. I have seen Dana 60's in them and I have seen AAM/corporate axles in them. If it is AAM/corporate it will most likely have a Gov-Lock limited slip. If it is a Dana, someone else might know.

 

[GHI]

I am in a similar situation and just want/need a few more inches of ground clearance. I have water holding tanks and a generator exhaust pipe that make me scared to hit the gas station driveway at the wrong angle.

I have been looking into this for quite some time. It always takes me a while to make a decision because I'm terrified of making the wrong decision. FWIW, I keep coming back to Boulder Off Road and their kit. I am most likely going to go that route even though my buddy says we can do it for much cheaper. I'm not scared to admit I am very limited in my mechanical skills and experience and the Boulder Off Road fellas seem to be pretty squared away. I personally want to have it done right the first time rather toy around with how to tweak whatever it is my buddy and I came up with.

.My Chevy Express is a bit newer, but I plan on keeping it for the long haul so I might as well do this sooner rather than later to enjoy those back roads I love camping on.

I have about 20,000 miles on the tires. I should probably start researching my next set now.

Good luck. I'll be following along here.

 

[ADVANTR]

Barefoot Boy, this pic's for you:victory:

Looks like Dana 60S. Just wondering about the limited slip in there.....

GHI, funny you mention that. My brother and I had a similar conversation. He was convinced we could lift the van for a less expensive way after checking out some Silverado 2WD lifts. I am in the same boat. I have read good things about the Boulder Off Road kits in general. I also plan to keep my van for some time. It is a 2005, but only has 52k miles. Overall, it is in quite good shape, spent most of its life in Virginia and I don't drive her much at all in the winter because it would be a pain in the butt to do any work on her after that. With all the salt they use in NY state, I am not sure how the local mechanic's don't go crazy. It makes simple jobs much more harder than they have to be. Bolts simply don't come off. The body of this van has no rust which is great. Very very minimal surface rust on some parts of frame.

Just curious if someone else may have direct experience with this kit who can lend some pearls. I could not find any reviews online and the info on the Boulder off road website is minimal.

 

[ADVANTR]

Alright guys, been doing some research here. Looks like GM used some oddball rear ends on the late model Savana and Express 2500 and 3500 series. There are not many options currently for a locker in the back. These do apparently have some sort of L/S in there now, but I can't find anywhere what type this is. Not sure if it is G-80. Any ideas about this?

I searched the ARB and Eaton websites as well as a few others and there are no current aftermarket options other than a Gov-Lock limited slip, which I think is just a replacement for the stock part. I have a few emails pending to a few people for more possible info.

One guy here took one of these apart on a Jeep forum for a possible conversion and came to the same conclusion. I have included the link, lots of other info here as well:

http://www.pirate4x4.com/forum/gene...pline-semi-floating-c-clip-i-need-locker.html

Finally, these are the stats on the rear end straight from Ring and Pinion database:

Dana 60 Super Rear, GM Express and Savana Vans.

Ring Gear Diameter: 9.750
Cover Bolts: 12
Ring Gear Bolts: 12
Spline Count: 33
Dropout: False
Pinion Support: False
Carrier Breaks: 4.10 / 4.56
Rear Suspension: Solid
Pinion Nut Size: 1-5/16

With the info in mind, I think I will likely leave the stock unit in there. I would certainly consider throwing in a E-locker or ARB, but I am not going to swap the whole axle in the back just for this purpose. Kind of a bummer, but hey, otherwise I am pretty psyched about the van and most people have stated it is pretty stout rear end in stock form. (I may have heard a similar comment about my GF some months back) :wings:

 

[4x4x4doors]

I believe GM labeled the rear LSD as a G80 on the RPO (Reg. Production Option) sheet but it stood for different things over the years.

I drive the small (S10 and Colorado) GMs and all 4 (91, 99, 01, 08) were labeled as the G80. The one in the 91 was seamless and effective. The 99 was a bit looser. The 01 was crisp in its engagement and the 08 has been solid and very dependable. I believe the variations had to do with type and also with the amount of wear each had. All except the 08 were bought used with 80K+ miles on them.

In short if it works for you, go with it. I did switch the 01 for an Eaton E-locker and there was a noticeable difference in the Limited and the Elocker.

 

[barefoot boy]

That is for sure a Dana. Most likely a 60. If you look on the casting webs around the center housing you will probably see a 60 cast in it. If you look closely on the axle tubes near the housing you should see a series of numbers stamped into the tube. Go to the Dana2 website and enter those numbers and you should get the entire build data for that rear end including what limited slip is in it. I agree with 4x4x4doors that G80 is the RPO code for limited slip; I do not think it means only an Eaton Gov-Lock. Look for the "Service Replacement Parts" sticker in your van. On pickups it is in the glove box. On my 88 Chevy van it is in the glove box. I do not know about your model van. This sticker lists every option that is on your truck including the axle ratio and w/wo G80.