Chevy & GMC Vans

Long intro, then questions … I recently purchased a 1991 AWD Tiger XL based on the astro. I thought my first question here would be on my underpowered drivetrain, but I’m back to the lift. I’m offroad a lot and would like to get 4” up. Not trying to squeeze huge tires in ~30” will do for now, but need some room for flex.

I got it with near-bald tires and a very saggy butt, weight = 5780 lbs. In the process of trying to get it to smog here in CA, I pulled the rear wheels for access to the gas fill and vent lines and saw why – upside down leaf springs and dead shocks.



I took it to a leaf spring shop nearby (Atlas Springs) – they do work for almost every suspension shop I’ve heard of and do custom leafs all day along. I ordered some Detroit Springs and had Atlas add a leaf to it to accommodate the heavy rear coach on this thing. http://www.atlasleafspring.com/products.html


Also the bushings/U-bolts: http://www.sdtrucksprings.com/index.php ... ts_id=7686


Problem – the stock astro leaves are 2.5” wide and these are 3” wide. No problem - they rebuilt my leafs and added a leaf so now it’s a 4/1 setup. Replaced front (Bilstein F4-B46-1047-HD) and rear (Bilstein F4-B46-2136-H0) shocks at the same time, these were free from another Tiger-lifting friend.

Before: front L = 29/ front R = 28/ rear L = 25/ rear R = 25.5, rode like a porpoise and very tippy in the turns




After: 29/30/28.5/29 Gained 3.5” in the rear for a reasonable price, happy me.



But it still rode like a mush-mallow, so onto tires. Original tires were 215/75/15 (27.7” dia) load range C. You can’t get AT load range D or E on 15” rims, so I went to 16” wheels and added 225/75/16 (29.3” dia) E tires. Cranked stock torsion keys to max, and trimmed maybe 1.5+” off the rear part of the front wheelwells due to rubbing at full turn.



With new tires it sits at: 31.5/32.5/30.5/31 – a little off camber which I’ll get to, but pretty good. Rides SO much better with the stiff sidewalls, and no more slowing for turns. Hard turns on flat surface, no problem – turning through dips I sometimes hit rubber since torsions are maxed.

Took it offroad a few times, maybe 40 miles total of washboard and 400 miles highway driving. Now the rear is sagging again – not as bad as before, but still … rear leafs are flat again, and maybe inverted a bit. Uphill right hand turns, right rear tire hits. Turning into driveways, either front tire hits on the dips.

Time to stop puttering around and lift this thing, instead of this see-saw approach. Don’t want to ruin new rubber. Currently it sits at 31.5/32.5/29.5/29.8

So on to questions (finally)
REAR:
Atlas will add a couple leafs (or make all new) and get me the lift in the rear, maybe adding a block? Do I want to use a shackle for offset or just have them make me a set of leafs and bolt directly? Pros/cons?

FRONT:
I’m not a fan of subframe spacers but after looking at this install of the 2” OV kit, I’m not opposed to doing that.
http://chevroletforum.com/forum/astro-d ... ans-25553/

My spacer bushings are hard and cracked they were on the list for destruction anyhow. But I’m not sure I can even do larger spacers because of the attachment of the Tiger coach. I’m digging thru SnoDrtRider’s thread for the home-brew approach, great info!

Have a call in to Gerald for the torsion keys – does ANYBODY else make a re-indexed key for the long arm Astros? Do we know how high does just the OV torsion keys get you? I want to get the rear leafs made correctly without too much rake.

I think I saw somewhere here that the bumper relocation bracket isn’t necessary – there are bolt holes higher up you can use for the mount? True on a 1991?

FRONT SHOCKS:
I know that Rancho 5000 is what OV sells with their kit. Not a fan of the Ranchos. Any other good options? Clearance in the front seems pretty tight, based on the install of the Bilsteins not sure what I can squeeze in there.

Hatching a different plan for the rear, mui heavy back there.

GEARING:
For a 4” lift (if I can get that), what is suggested for re-gearing front/rear. My drivetrain is definitely struggling already, don’t want to add to the problem.

Thanks for listening, any input much appreciated!

The Overland shackles are nice because the height is adjustable.

3.73 or 4.10 gears would work well with your 29" tires, but I think your carrier has to be compatible. LiftedAWDAstro knows about that. What is your current gear ratio?

The springs in your first pic were not the stock springs to start with. Tiger apparently already upgraded them. It came from the factory with a fiberglass mono spring. Having your shop make up new ones would be the best bet as anything pre made for an Astro would not be setup for the added weight you have. I do not recommend the torsion keys at all. Way too much stress on the steering/suspension parts. I had them and took them off. I have used the two inch block setup from OLV for up front numerous times with good results. With the weight of your rig and the tires you have I would say 4.11 gears would be mandatory if not the minimum. And you are correct, you do not need the bumper relocation kit.

Not sure what my current setup is, digging through RPO codes to find out. Hold please ... k, here it is: GT4 = 3.73:1

Guess the primary question is - does anyone except OV make the re-indexed torsion keys? I may be SOL on the body part.

Copied from elsewhere here
GT4 Rear Axle: 3.73 Ratio
GT5 Rear Axle: 4:10 Ratio
GU5 Rear Axle: 3.23 Ratio
GU6 Rear Axle: 3.42 Ratio

Nice Tiger, I am a fan of those, lets see the interior!

lockdoc wrote:The springs in your first pic were not the stock springs to start with. Tiger apparently already upgraded them. It came from the factory with a fiberglass mono spring. Having your shop make up new ones would be the best bet as anything pre made for an Astro would not be setup for the added weight you have. I do not recommend the torsion keys at all. Way too much stress on the steering/suspension parts. I had them and took them off. I have used the two inch block setup from OLV for up front numerous times with good results. With the weight of your rig and the tires you have I would say 4.11 gears would be mandatory if not the minimum. And you are correct, you do not need the bumper relocation kit.

Good info, thanks. But if I'm unable to use blocks due to the hard connect of the coach to the frame, is there another choice besides torsion lift up front? Don't think I want to go spindle/coil, ugh.

I believe you should have no problem installing 4.11 gears.

Wiley wrote:Copied from elsewhere here
GT4 Rear Axle: 3.73 Ratio
GT5 Rear Axle: 4:10 Ratio
GU5 Rear Axle: 3.23 Ratio
GU6 Rear Axle: 3.42 Ratio

Nice Tiger, I am a fan of those, lets see the interior!

Ha - thanks! I put some interior pics up over here : viewtopic.php?f=20&t=8378

TB - good to know, needs all the help it can get!

suntinez wrote: Good info, thanks. But if I'm unable to use blocks due to the hard connect of the coach to the frame, is there another choice besides torsion lift up front? Don't think I want to go spindle/coil, ugh.

I've never looked under a motorhome conversion, but unless they have tied the coach to the front subframe, you should be fine. I'm not sure why they would do such a thing... and even if they did, hopefully it was done in such a way that it can be unbolted, meaning there would likely be a way to adapt to it. (The front subframe needs to drop for engine removal [so says GM] so I'm sure it hasn't been modified.)

I would be interested in see pictures how the sub frame is tied to the motor home and then to the rear.It's been kind of a question in my mind for awhile.

Me too, G.

Linda, I agree with LockDoc and Dean regarding the torsion keys and their resulting issues.

Does yours have the rear air suspension as in the brochure you sent me?

Linda sent this to me a short time ago. Somewhere I heard that the Tiger was welded to the Astro floor...even if that is true, it all should all just be bolted to the frame.

T.Low, not unless those frozen chunks of metal I replaced with Bilstiens were air shocks at one time (unlikely). No airbags or anything. I'll get some pics of underneath soon.

edit - here's a link to some pics down below: http://s259.photobucket.com/albums/hh31 ... nderneath/

This is the passenger side where astro meets Tiger, the wooden box is the coach entry step, which fits between the aluminum frame there.



It looks pure astro from this point forward, spent quite a while looking at the attachment points.

I don't see why I can't slide 2" pucks in up front, so going to order those and the re-indexed torsion keys. May not need the keys? Beef up the rear leafs, and see how it goes. Not totally sure what I'm doing on the shocks yet.

It certainly does look like a standard sub frame for a Astro.Should work out for the pucks.Not sure I would mess with the torsion bar keys as Lockdoc advised you.Maybe while your there teat the bottom wooden step area with something to preserve it.Actually all the wood on the bottom.

Oh yeah-when you do the puck lift you want to do one side at a time.Sure makes that easier.

From that last pic I can see no reason why you couldn't use the blocks up front like any other Astro. Don't forget you will need a 2WD steering linkage along with it.

lockdoc wrote:From that last pic I can see no reason why you couldn't use the blocks up front like any other Astro. Don't forget you will need a 2WD steering linkage along with it.

I was wondering about that - any info on where to get?

Gary, good idea about undercoating the wood.